A Novel Multi-functional Zn-MOF Fluorescent Probe Demonstrating

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A Novel Multi-functional Zn-MOF Fluorescent Probe Demonstrating Unique Sensitivity and Selectivity for Detection of PA and Fe3+ Ions in Water Solution Xinrui Zhuang, Xiao Zhang, NanXi Zhang, Yan Wang, Liyan Zhao, and Qingfeng Yang Cryst. Growth Des., Just Accepted Manuscript • DOI: 10.1021/acs.cgd.9b00704 • Publication Date (Web): 16 Aug 2019 Downloaded from pubs.acs.org on August 16, 2019

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Crystal Growth & Design

A Novel Multi-functional Zn-MOF Fluorescent Probe Demonstrating Unique Sensitivity and Selectivity for Detection of PA and Fe3+ Ions in Water Solution Xinrui Zhuang,† Xiao Zhang,* † Nanxi Zhang,§ Yan Wang,† Liyan Zhao,† Qingfeng Yang,// † MIIT key laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, People’s Republic of China. § School of Life Science and Technology, Harbin Institute of Technology, Harbin, 150080, People's Republic of China. // State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical, Engineering, Ningxia University, Yinchuan, 750021, China

ABSTRACT A novel metal organic framework {Zn2(tpt)2(tad)2·H2O} (tpt = 2,4,6-Tri(pyridin-4yl)-1,3,5-triazine, H2tda = 2,5-thiophene dicarboxylic acid) with a 3-fold interpenetrating 3D framework was successfully synthesized under hydrothermal condition. As expected, 1 displays excellent luminescence and stability, which can stably exists in different pure organic solvents and

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Crystal Growth & Design 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

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acid-base solution. 1 can be considered as an ultrasensitive sensor for detection of Fe3+ ions and PA with high selectivity by fluorescence quenching behaviors. Meanwhile, the fluorescence test plates shows that the visible color change of Fe3+ ions can be easily observed by naked eyes in the process detection, which makes Fe3+ ions more easily recognized in various metal ions. In addition, the mechanism of fluorescence quenching is also further discussed.

1 INTRODUCTION Nowadays, the effective detection of nitroaromatic compounds (NACs) and metal ions has drawn great interest due to its importance in human health and homeland security.1 NACs has been recognized as a kind of hazardous environmental pollutant because it is difficult to be removed or degraded, but it is still extensively used in a variety of industries including dyes, fireworks and pharmaceuticals.2-3 2,4,6-trinitriphenol (PA) as an important member of NACs family, which is a more powerful explosive than 2,4,6-trinitrotoluene (TNT), has been widely used in the fireworks, rocket fuels, and manufacture of landmines.45

Massive of PA is discharged into the environment from chemical industries that has

caused a series of problems for wildlife and humans. On the other hand, iron anion (Fe3+) has extensive applications in the industry and plays key roles in various biochemical processes at cellular level.6-8 However, excess of Fe3+ can be harmful to the nucleic acids and proteins because Fe3+ can catalyze the production of reactive oxygen species by the Fenton reaction.9-11 Therefore, developing highly efficient methods for quick, reliable and robust detection of PA and Fe3+ ions is one of great significance in human health and environment.


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Recently, luminescent metal-organic frameworks (LMOFs) have raised increasingly attention due to its remarkable sensitivity, highly selectivity, operability simplicity and dual compatibility in solid and solution media.12-13 In order to achieve highly responsive fluorescent sensing to analyte, an efficient strategy to design and synthesize the MOFs with excellence fluorescent property is to select the organic ligand with -electron conjugated system, for the following reasons. Firstly, the organic ligand bound by metal anions in MOFs will reduce the nonradioactive transition and show the strong emission.14-15 Secondly, the capillary effect of channel of MOFs can pre-concentrate the dilute analyte and give rise to better selectivity. Furthermore, specific functional groups can be easily introduced into MOFs to interact with the chosen analytes and improve the selectivity.16-18 Recently, a large number of fluorescent chemosensors based on MOFs have been investigated for the detection of NACs and metal ions. However, to the best of our knowledge, it is still the large challenge to rationally design and synthesize the MOF-based chemosensors with high sensitivity and selectivity for analytes in aqueous. Based on above discussion, in order to obtain MOF based fluorescent probe which demonstrate unique sensitivity and selectivity for analytes in water solution, we selected thiophene-2,5-dicarboxylic acid (H2tda) and 2,4,6-Tri(pyridin-4-yl)-1,3,5-triazine (tpt) as ligands, and Zn2+ as metal centre to construct MOFs, the reason as followed: (a) Zinc with d10 electronic configuration is an outstanding candidate for photoluminescence materials, and are usually used to construct MOFs with excellent fluorescence properties. (b) H2tda not only behaves attractive bridging performance which can be attributed the angle of 120o between two carboxyl groups, but also exhibits the excellent electron-transferrin ability due to electrons rich in thiophene ring. (c) tpt is -electronic conjugated organic compound and


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has rigid structure which is in favor of the stability of MOFs with excellent fluorescence properties and (d) the conjugated structure of tpt and H2tda is beneficial to electronic transition leading to the enhancement of photoluminescence. Therefore, the MOFs built by H2tda, tpt and Zn2+ will show intriguing architectures and topologies with excellent luminescence properties that can be used for the detection of NACs and metal ions. Based on above strategy, we report a highly luminescent MOF [Zn2(tpt)(tda)2]H2O (1) possessing a four-connected uninodal net. 1 can serve as a promising dual-functional fluorescence sensors for detection and recognition of PA and Fe3+ ions via fluorescence quenching with remarkable selectivity and sensitivity in aqueous solution. Furthermore, the visible color changes in the detection process make Fe3+ easy to be distinguished among various metal ions by the naked eye.

2 EXPERIMENTAL SECTION 2.1 MATERIALS AND METHODS All reagents and solvents were commercially available and used without further purification. Powder X-ray diffraction (PXRD) measurements were carried out on a Bruker D8 Advance X-ray diffractometer with Cu Kα radiation. Infrared (IR) spectra were measured on a Spectrum 100 spectrometer using KBr pellets (400 - 4000 cm-1). Thermogravimetric analysis (TGA) was carried out between room temperature and 400 °C under a flow of N2 at a heating rate of 10 °C min-1. The fluorescence emission spectra were measured on a Cary Eclipse Luminescent spectrophotometer. Elemental analyses (C, H, and N) were performed on a PerkinElmer 2400. The UV/Vis absorption spectra were recorded at room temperature on a Cary 4000 UV/Vis spectrometer. Point symbol and topological analyses were conducted by using the TOPOS program package.19


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2.2 SYNTHESIS A solid mixture of tpt (0.015 mmol, 0.009g), H2tda (0.03 mmol, 0.010g) and ZnSO4·6H2O (0.035 mmol, 0.021) were dissolved into 6 mL of mixture solvent containing water and CH3CN (5:1), then treated by ultrasonication for 10 min. Next, the mixture solution was transformed to 20 mL Teflon reactor and heated at 150 oC for 72 h. White block crystals were obtained after slowly cooling down room temperature and the yield is up to 63.2 % based on ZnSO4·6H2O. Analysis cal. (%) for C30H18N6O9S2Zn2: C 43.26%; H 3.65%; N 22.36%. Found: C 43.53%; H 3.67%; N 22.23%. 2.3 SINGLE-CRYSTAL X-ray DIFFRACTION ANALYSIS All data were recorded on an Agilent technology SuperNova Eos dual system with a (Cu-Kα, λ = 1.54184 Å) microfocus source and focusing multilayer mirror optics at room temperature. The structures were solved and refined using the full matrix least-squares method based on F2 using the SHELXS-2018 and SHELXL-2018 programs.20-21 The carFboxyl group (O5-C7-O6) of tda2anion is disorder, and splits two parts with the site occupancy factors being 0.55 and 0.45. The disordered carboxyl group was refined anisotropically. The ratios of the maximum and minimum displacement parameters for the disordered atoms were larger than 2, and were restrained. The hydrogen atoms of ligands were localized in their calculated positions and refined using the riding model. All non-hydrogen atoms were refined anisotropically. Further details of the X-ray structural analyses are given in Table 1. Selected bond lengths and bond angles of 1 are listed in Table S1. Table 1. Crystal data and structure refinement for 1. Identification code

1

Empirical formula

C30H18N6O9S2Zn2

Formula weight

801.36


5


aR

1

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Temperature/K

293(2)

Crystal system

monoclinic

Space group

P21/c

a/Å

10.14670(10)

b/Å

20.2077(2)

c/Å

15.5165(2)

β/°

91.2420(10)

V/Å3

3180.78(6)

Z

4

ρcalcg/cm3

1.673

μ/mm-1

3.647

F(000)

1616.0

Radiation

CuKα (λ = 1.54184)

2θ range for data collection/°

8.716 to 141.308

Index ranges

-11 ≤ h ≤ 12, -23 ≤ k ≤ 24, -13 ≤ l ≤ 18

Reflections collected

12362

Independent reflections

6002 [Rint = 0.0205, Rsigma = 0.0266]

Data/restraints/parameters

6002/18/473

Goodness-of-fit on F2

1.037

Final R indexes [I2σ (I)]

R1 = 0.0326, wR2 = 0.0871

Final R indexes [all data]

R1 = 0.0378, wR2 = 0.0913

= ||Fo| - |Fc||/|Fo|. bwR2 = |w(|Fo|2 - |Fc|2)2/|w(Fo2)2|1/2

3 RESULTS AND DISCUSSION 3.1 CRYSTAL STRUCTURE DESCRIPTION Single crystal X-ray diffraction analysis reveals that 1 crystallizes in the monoclinic P21/c space group, displaying a novel 3-fold interpenetrated 3D architecture. The asymmetric unit of 1 contains two crystallographically unique Zn(II) ions, two tda2- anions, one tpt and one lattice water (Figure


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S1). The Zn1 center exhibits two kinds of geometry, distorted tetrahedron (ca. 55%) and distorted tetragonal pyramid (ca. 45%), because of the disorder of carboxyl groups of tda2- anion. In the disordered tetrahedron/tetragonal pyramid, the Zn(II) center is four/five-coordinated by two nitrogen atoms from two different tpt ligands and two/three oxygen atoms from two different tda2anions. The distances of Zn-N [2.046(2)-2.067(2) Å] and Zn-O [1.901(6)-2.271(13) Å] are in the normal ranges of those observed in reported Zn (II) compounds.22-23 The central Zn2 center displays a distorted tetragonal pyramid, defined by four oxygen atoms [O8, O4iii, O3iv, O7v,symmetry codes: (iii) 1+x, 0.5-y, -0.5+y; (iv) 2-x, -0.5+y, 1.5-z; (v) 3-x, -y, 1-z] from four different tda2- anions a least-square plane with average deviation 0.008 Å, and one nitrogen atom [N2ii; symmetry codes: (ii) 1-x, -0.5+ y, 0.5-z] from tpt ligand in the axial sites. the Zn–N distances and Zn–O distances are 2.061(18) Å and 2.027(2)-2.041(2) Å, respectively, which are in the normal ranges of those observed in reported Zn(II) complexes.24-25 Two adjacent Zn2 atoms are bridged by four µ2-η1:η1-carboxylate groups from four tda2- anions into a paddle wheel dimeric [Zn2(CO2)4] with C4 symmetry, in which the Zn−Zn distance is 3.013 Å. As shown in Figure 1, the disordered tda2- anions are two linkers and use two carboxylate groups to bridge the Zn1 centers and the [Zn2(CO2)4] dimers. The tpt ligand is a three-way tube linker and adopts the μ3coordination mode to coordinate with two Zn1 centers and one [Zn2(CO2)4] dimers. Therefore, a two-dimensional (2D) sheet structure with two types of caves is formed. Cave A is pentagon constructed by two Zn1 atoms, one dimer, one tda2- anion and two tpt ligands with the side lengths of1.48 Å, 7.92 Å, 7.42 Å, 7.58 Å, 9.36 Å.. However, cave B is hexagon formed by two Zn1 atoms and two dimers, two tpt ligands and two tda2- anions with the side lengths of 9.41 Å, 10.24 Å, 7.57 Å, 9.07 Å, 10.28 Å, and 7.29 Å.


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Figure 1. The 2D sheet of 1 featured two type of caves, the pentagonal cave A and the hexangular cave B. The 2D sheets are further pillared by the orderly tda2- anions to construct the 3D framework. The separation between the adjacent sheets is about 10.2 Å (Figure 2). A feature of 1 is the space of interlamellar is separated by orderly tad2- anions and forms two types of tunnels along b axis. The dimensions of A and B are 7.1 × 10.2 Å and 10.2 Å × 14.5 Å, respectively. Despite the nature of the 3-fold interpenetration, 1 still forms 1D open tunnels with the dimensions ca. 3.2 Å × 7.1 Å in which the lattice water molecules are trapped by O-HO hydrogen bonds.

Figure 2. The 3D framework of 1 constructed from 2D sheet pillared by tda2- anions with A and B tunnels.


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From the topological point of view, if each Zn1 center, being connected by two tda2- anions and two tpt ligands, can be considered as a four-connected node, each dimer can simplified as a sixconnected node, because it is connected by two tpt ligands and four tda2- anions, each tda2- anion is simplified by a linear linker, and tpt ligand is simplified by a three-way tube linker, this framework can be simplified into a 3,4,6-c net with Schläfli symbols {53}2{5462}2{56647293} (Figure3a). As far as we know, this type of topology has not been reported yet. Because of the spacious nature of the single framework, the tunnels in a single 3D framework can be interpenetrated by two identical frameworks, and generate a 3-fold interpenetrating 3D framework (Figure 3b).

Figure 3. (a) the topological of 1 simplified into a 3,4,6-c net with Schläfli symbols {53}2{5462}2{56647293}, (b) A 3-fold interpenetrating 3D framework formed by interpenetration of two identical frameworks. 3.2 PXRD, IR AND THEEMAL PROPERTY


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The PXRD pattern of 1 matches well with the simulated patterns based on the single-crystal construction, indicates that 1 has high phase purity (Figure S2). In addition, the IR spectrum of 1 was studied, as shown in the Figure S3, the strong absorption at 1646 cm-1 and 1561 cm-1 were attributed to the C=C and C=N stretching vibrations, respectively. The peak at 1460 cm-1 was resulted from C=O vibrations. And the strong peak at 1365 cm-1 in 1 was C-C vibration, another, the sharp peak at 772 cm-1 was characteristic peak of meta substitution of dicarboxylic acid. To investigate stability, thermogravimetric analysis (TGA) of 1 was carried out under nitrogen environment and the heating rate was 10 oC/min. As shown in the Figure S4, the TGA curve of 1 displays three step of weight loss. The first weight loss ranging from 30 oC to 100 oC is connected with the water molecular adsorbed on the surface of the crystal. The second weight loss of 2.27 % (ca. 2.25 %) from 256 oC to 337 oC attributes to the loss of one free crystal water molecular. The last weight loss step after 337 oC corresponds to the collapse of framework. 3.3 SABILITY OF 1 IN ACID-BASE SOLUTION Stable existence in acid-based solution with different pH is a test criterion for the performance of sensors. 1 was immersed into the acid-based solution with different pH value for 12 h, filtering and then measuring the PXRD, respectively. As shown in the FigureS5, the patterns of 1 before and after pretreatment are closely matched, implies that the framework of 1 still remains intact. The experimental results show that 1 has excellent tolerance of acid-base. Meanwhile, the PXRD pattern of 1 in various organic solvents were also investigated, respectively. As shown in the Figure S6, the results display that 1 can maintain integrity of framework after dealing with organic solvents. What is more, the SEM imagine of 1shows that the surface of MOF material after treating with different solution has no change compared with blank sample, which further implying that 1 has excellent stability (Figure S7).


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3.4 PHOTOLUMINESCENT PROPERTIES In view that 1 was constructed from -conjugated ligands and d10 metal centers, we speculated that it may be a good photoactive material, so the solid-state photoluminescent of the free ligands and 1 were investigated at room temperature. As shown in the Figure S8, the free tpt ligand and 1 display strong emission peak at 394 nm (ex = 282 nm) and 386 nm (ex = 280 nm), respectively. H2tda ligand shows emission peak at 365 nm (ex = 285 nm). We can find that tpt plays significant role in fluorescence of 1. The result shows that the emission band of 1 may be attributed to the intraligand *   and *  n transition due to the d10 nature of Zn2+ ions. Furthermore, the liquid luminescence property of 1 and tpt (molar ratio = 1:1) were investigated (Figure S9). Compering with free tpt ligands, the emission intensity of 1 significantly enhanced which may be explained that after coordinating to central metal ions (Zn2+), the non-radiative relaxation in the ligands reduce leading to the increasing of emission, besides which can be related with the increasing electronic communication between the adjacent coordinated ligands molecules resulted from metal cneter.22 In addition, 2 mg of 1 were separated into acid-based solution with different pH and measured fluorescence spectral. As shown in the Figure S10, after dealing with acid-based solution, the fluorescence intensity of 1 is well as the origin one, suggesting that the pH has no influence on the fluorescence of 1. What’s more, the fluorescence property of 1 in different organic molecules was determined. As shown in the Figure S11, different solvents have different effect on the luminescence intensity of 1 which can be attributed to solvent effects.26-27 Obviously, the luminescence of 1 was completely quenched by NB solution compared with other solvents which implied that 1 can be served as fluorescence probe to recognize NACs in aqueous phase. 3.5 DETECTION OF NITRO COMPOUNDS


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Considering that NB displays completely quenching effect on fluorescence intensity of 1, we further investigate its sensitive and selective ability towards different NACs. Thus, a series of fluorescence titration experiments were carried out by gradually dropping the concentration of different NACs (5 mM) into suspension of 1, including nitrobenzene (NB), p-nitrophenol (4-NP), 2,4-dinitrotoluene (2,4-DNT), m-nitrotoluene (m-NT), m-dinitrobenzene (m-DNB), p-nitrotoluene (p-NT), o-nitrotoluene (o-NT), picric acid (PA) and o-nitrotoluene (o-NT). The detail of fluorescence intensity of 1 after addition of different NACs were recorded in the Figure S12 and Figure 4a, respectively. It is obvious that the fluorescence of 1 with addition of PA was almost completely quenched in contrast with other NACs, the quenching efficiency reached 96 % (Q = (I0-Ii)/I0  100%) when the concentration of PA was to 80 µM (Figure 5). The results show that 1 can selectively detect PA by the property of luminance quenching in aqueous solution. Control 2 L 4 L 6 L 8 L 10 L 12 L 16 L 24 L 32 L 48 L

600

400

200

30

(b)

25

2.2

R2=0.99

2.0

Ksv=7.8104

1.8   

(a)

20

1.6 1.4 1.2

  

800

Intensity (a.u)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

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15

1.0

2

4

6

8

10

12

14

16

18

Concentration (M)

10 5 0

0 300

320

340

360

380

400

420

440

0

10

20

30

40

50

60

70

80

90

Concentration (M)

Wavelength (nm)

Figure 4. (a) The luminescence intensity of 1 upon incremental addition of PA solution (5 mM) in water. (b) Stern-Volmer plot for the luminescence intensity of 1 upon the addition of PA solution (5 mM) in water


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Figure 5. Stern-Volmer plots of analytes in higher concentration range of analytes (up to 80 μM). The quenching efficiency between PA and 1 can be quantitatively calculated using Stern-Volmer (S-V) equation: (I0/I) = 1 + KSV [Q], I0 and I is the emission intensity of 1 before and after addition of PA, respectively, Ksv is quenching constant, [Q] is the concentration of PA. As shown in the Figure 4b the S-V plot displays linear relation at low concentration of PA, while shows upward bending trend at high concentration of PA, which can be attributed to the self-absorption between MOFs and analytes. At low concentration, the KSV is up to 7.8  104 M-1, which was comparable to the previous reported MOF for detection of PA.16, 28-29 Meanwhile, the limit of detection was further calculated according to the corresponding the data. As shown in the Figure S13, the value of detection limit is up to 2.56  10-6 M, suggesting that 1 can act as an excellent sensor to detect PA with high selectivity and sensitivity in aqueous solution. It is worth mentioning that the proportion of 1 and solvent is up to 1:12 in all titration experiments, implying that 1 as fluorescence probe has ultra-high sensitivity. And the fluorescence response can be comparable to the reported MOFs. The detail is recorded in the table 2


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Table 2. A comparison of various fluorescent materials used for sensing PA Sensors based on MOFs

Media

Analyte

Ksv (M-1)

[MOFs]

Ref.

[Cd(NDC)0.5(PCA)]·Gx

water

PA

2.9  104

0.5 mg·mL-1

16

Ur-MOF

water

PA

10.83  104

0.5 mg·mL-1

30

[Zn2(L)2(dpyb)]

DMA

PA

2.4  104

0.5 mg·mL-1

31

[Zn2(apo)2]·H2O

EtOH

PA

3.16  104

0.75 mg·mL-1

32

{[Cd(H2TCPP)]·2H2On

water

PA

8.5  104

0.25 mg·mL-1

33

[Cd(5-BrIP)(TIB)]n

water

PA

2.68  104

1 mg·mL-1

34

1

water

PA

7.8  104

0.08 mg·mL-1

To better understand the reason behind fluorescence quenching of 1 in the presence of PA, the quenching mechanisms were deeply studied. Usually, the common accepted mechanisms are as followed: (a) photo-induced electron transfer (PET), (b) the collapse of framework of 1 after introducing analytes, (c) resonance energy transfer (RET). The most of NACs are belong to electro-deficient compounds with the low LUMO energy, which can easily accept excited electron from electron-rich fluorophores (MOFs) through donor-acceptor (D-A) interactions leading to fluorescence quenching. The HOMO-LUMO energies of ligands and all NACs were calculated using density functional theory (DET) at the B3LYP/6-31+G* lever. The LUMO energy of NACs behaves lower, the ability of NACs to accept electrons become stronger and the fluorescence quenching is more significant.14, 35-36 As shown in the FigureS14 and Table S2, compared with other NACs, the LUMO energy of PA is lowest and the excited electron of 1 can be more easily accepted by the LUMO of PA, which accord with the result of the titration experiment. Furtherly, the cyclic voltammetry (C-V) between 1 and PA was in favor of the PET theory in experiment. Platinum, glassy carbon and Ag/AgCl were selected as auxiliary, working and reference electrode, respectively. The 1 M of KCl solution was as supporting electrolyte removed O2 dealing with N2 at room temperature. As shown in the Figure 6, compared with the single system of 1, the reduction


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current of 1 after addition of PA was significantly enhanced, suggesting that the electron transition took place between analyses and electron material (Zn-MOF). In addition, the reduction potential of hydrogen evolution (-0.455 V) was disappeared and the reduction potential of PA, -0.679 V was presented under UV light at 235 nm in the presence of PA which indicated that the excited electron of electron material (Zn-MOF) was accepted by PA, the reduction of PA play key role in the whole system, rather than H+. The experimental results matched with the phenomenon of fluorescence quenching of 1 resulting from PA. So the PET theory can contribute to the luminescence quenching of PA to 1.

(a) 1+UV (b) 1+UV+PA

-6

5.0x10

0.0 Current / mA

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


-6

-5.0x10

-5

-1.0x10

-5

-1.5x10

-5

-2.0x10 -1.00

-0.75

-0.50

-0.25

0.00

0.25

0.50

0.75

1.00

Potential / V

Figure 6 C-V curve of compound 1. (a) 1 under UV light (235 nm), (b) 1 with UV light (235 nm) after addition of PA, measured in 0.1 M of KCl in acetonitrile at a scan rate of 25 mV s-1. Secondly, the PXRD pattern of 1 was agreement with the original one, so the framework of 1 still maintain integrity after detection of PA, suggesting that the fluorescence quenching of 1 did not attributed to the collapse of crystal framework (Figure S15). Based on previous research, resonance energy transfer which is depend on the degree of overlap between the absorption of analytes and emission band of fluorophore is another main mechanism for luminescence


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quenching of sensor. The extent of overlap gets wider, the efficiency of fluorescence quenching is higher. Therefore, the UV-Vis spectra of different NACs were monitored and recorded in detail in the Figure S16. The result shows that PA has maximum overlap with the emission spectral of 1, fitting well with the result of quenching efficiency. In addition, the absorption of p-NT and o-Np also has part overlap with 1 causing slight quenching response to luminescence intensity of 1. Conclusion demonstrated that 1 can selectively and sensitively detect PA which may mainly attributed to the combination of PET and RET. 3.6 DETECTION OF METAL IONS Metal ions play essential roles in biological systems and human health, so it is significant for us to accurate and real-time detection of them. The remarkable fluorescence property of 1 in liquid solution encourages us to explore its potential ability in the field of detecting metal ions. Various aqueous solution of M(NO3)x (0.1 M) containing different metal ions (Mx+ = Li+, K+, Na+, Ca2+, Ba2+, Mg2+, Hg2+, Mn2+, Zn2+, Al3+, Ni2+, Co2+, Cu2+, Fe3+, Ag+,) was separately dropped into suspension of 1 and tested the luminescence spectral under consistent conditions. As shown in the Figure S17, only Fe3+ ions display a significant quenching effect on the emission intensity of 1 suggesting the high selectivity of 1 for specific detection of Fe3+ ions in water solution. On the other hand, in order to determine the sensitivity of 1 for sensing Fe3+ ions in water solution, the titration experiments were carried out. Fe3+ ions solution (20 mM) was gradually added into the suspension of 1, followed by measuring fluorescence intensity at 385 nm, respectively. As shown in the Figure 7a, with the increasing of concentration of Fe3+ ions, the emission intensity of 1 continuously decreased, and the quenching efficiency between 1 and Fe3+ ions is up to 89 % when the concentration of Fe3+ ions is up to 0.38 mM (38 µL). At low concentration, the quenching constant (Ksv) of Fe3+ ions for fluorescence intensity of 1 can be


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accurate calculated using S-V equation, the result is 4.6  104 M-1(Figure 7b). Furthermore, the limit of detection for Fe3+ ions based on the corresponding data, up to 4.72  10-6 M (Figure S18), which is comparable with other sensor of Fe3+ ions previously reported.8,

10, 37-39

In addition,

selective detection of object metal ion under the interference of other metal ions is necessary. So competitive experiments of Fe3+-1 under existing other metal ions were studied. 20 µL of Fe3+ ions solution was dropped into the suspension of 1 containing other metal ions (40 µL). And then the fluorescence intensity of 1 were monitored and recorded in the Figure S19. The quenching effect caused by Fe3+ ions keeps invariant in the presence of other metal ions, indicating that 1 can selective recognize Fe3+ ions resisting interference of analogues. The recyclable performance of probe makes increasing attention in the field of detection. So the recovery experiment of 1 as the Fe3+ ions probe was further investigated. 3 mg of 1 was immersed into Fe3+ ions solution (20 mM) to form Fe3+-1, and then the sample was washed several times with distilled water. As shown in the Figure S20, the fluorescence intensity of 1 was recovered compared with Fe3+-1. Meanwhile, the PXRD demonstrated that the framework of 1 had remained intact after regeneration (Figure S21). The above discussions indicate that the high quenching constant, low limit of detection, strong interference immunity and regeneration ability make 1 can act as outstanding probe for detection of Fe3+ ions in water solution with high selectivity and sensitivity.


17


800 600 400 200

5

(b)

2.4 2.2 2.0

4

2

R = 0.98 4 Ksv = 4.610

1.8

I0I

Control 2 L 4 L 6 L 8 L 10 L 12 L 14 L 16 L 18 L 20 L 22 L 24 L 26 L 28 L 30 L 32 L 34 L 42 L 52 L 68 L 84 L 100 L

(a)

1.6 1.4 1.2

I0  I

1000

Intensity (a.u.)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

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3

1.0 0.005

0.010

0.015

0.020

0.025

0.030

Concentration (mM)

2

1

0 320

340

360

380

400

Wavelength (nm)

420

440

0.00

0.01

0.02

0.03

0.04

0.05

0.06

0.07

Concentration (mM)

Figure 7. (a) The luminescence intensity of 1 upon incremental addition of Fe3+ ions solution (20 mM) in water. (b) Stern-Volmer plot for the luminescence intensity of 1 upon the addition of Fe3+ ions solution (20 mM) in water. It is noticeable mentioned that the luminescence intensity of 1 and concentration of Fe3+ ions displayed liner relationship at low concentration and shows an up-bending non-linearity at higher concentrations which can be explained by static or dynamic mechanism. The distinction of two mechanism is the change of fluorescence lifetime after addition of analytes. Bonding interaction between quencher and fluorophore leading to the formation of non-radiation complex will occur in the static process, the fluorescence lifetime of sensor will remain unchanged. In the dynamic process, the fluorophore undergo collision with quencher and present energy transfer among them. The lifetime of sensor material will decrease. As shown in the Figure 8, the fluorescence lifetime of 1 remained unchanged as the increasing concentration of Fe3+ ions Therefore, the behavior of quenching for Fe3+-1 is belong to static quenching, rather than dynamic quenching.40


18

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Compound 1 3+ Compound 1 +Fe

2000

1500

Counts

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


1000

500

0 20

22

24

26

28

30

32

34

Time (ns)

Figure 8. The fluorescence lifetime of 1 before and after addition of Fe3+ ions (12 µL, 20 mM). It is simple and convenient to detect metal ions with a naked eye colorimetric sensor, herein, a class of fluorescent test plates were prepared for sensing of various metal ions. The suspension was prepared containing 2 mL of a 0.5 % water solution of carboxymethylcellulose sodium (CMC) and 1 (0.02 g ), then spread on glass substrates, followed by dying at room temperature. Next, various metal ions solution (10 µL 25 mM) were dropped on the test plates, respectively. As shown in the Figure 9 the fluorescent color of the test plate dropped with Fe3+ ions become black under irradiation with a UV light at 365 nm which can be obviously recognized by naked eye, while the others are not change. In a word, the fluorescent test plates showed a continent, fast response and sensitive and selective method to sense Fe3+ ions.


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Figure 9. Optical images of the test plates after immersion in solutions with various metal ions under irradiation with a UV-vis light at 365 nm. To better explain the quenching in the luminescence intensity of 1 in the presence of Fe3+ ions, the UV-vis spectral of all metal ions solution were measured and recorded in the Figure S22. It is obvious to find that Fe3+ ions solution exhibit broad and strong absorption band at 260 - 400 nm, which not only just cover the excitation light (ex = 282 nm), but also has maximum overlap with emission band of 1 compared with other metal ions, which implies the emission and excitation light of compound 1 was absorbed by Fe3+ ions solution leading to the fluorescence quenching. Besides, the PXRD of 1 after detecting Fe3+ ions were also monitored and found that the pattern matched well with the original one (Figure S23), suggested that the framework of 1 remained intact and the fluorescence quenching between 1 and Fe3+ ions did not result from the framework collapse of 1. Moreover, the introduction of metal ions may diffuse into the pore channel of 1 and the electronic structure of ligands in framework would be disturbed. So the energy transfer between ligands and metal canter in framework was reduced causing the fluorescence quenching of 1. The X-ray photoelectron spectroscopy (XPS) of Fe3+-1 can confirmed that the Fe3+ presented in the framework of 1 (Figure S24) and the typical characteristic peak of Fe3+ was founded at 713 eV and 726 eV. And the ions exchange between Fe3+ ions and 1 can be excluded vis recovery experiment. Therefore, RET, competition between excitation of 1 and absorption of Fe3+ ions, and the interaction between Fe3+ ions and the framework of 1 play a significant role in the detection of Fe3+ ions by 1. Meanwhile, the non-liner relationship of S-V plot at high concentration of Fe3+ ions can also suggest the quenching process is complicated.

4 CONCLUSIONS


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In conclusion, a 3D MOF based on Zn(II) was successfully synthesised under hydrothermal condition, which displays a 3-fold interpenetrating 3D framework and can be simplified into a 3,4,6-c net with Schläfli symbols {53}2{5462}2{56647293} from topological point of view. 1 not only displays good thermal stability, but also can be stable in the different pure organic solvents and acid-based solution. In addition, the high sensitivity and selectivity for PA and Fe3+ ions in aqueous make 1 act as a ultrasensitive fluorescent sensor by luminescence quenching behavior in the field of detection. Furthermore, the quenching mechanism between 1 and PA/Fe3+ were discussed and testified by a class of data, respectively. We confirm that 1 can be seen as a good sensor for detecting PA and Fe3+ in the future.

5 CONFLICTS OF INTEREST There are no conflicts to declare. 6 ASSOCIATED CONTENT Supporting Information Electronic supplementary information (ESI) available: CCDC reference numbers 1910412 for 1. For ESI and crystallographic data in CIF or other electronic format. See DOI: 10.1039/x0xx00000x

7 ACKNOLEDGEMENTS This study was financially supported by the Foundation of State Key Laboratory of Highefficiency Utilization of Coal and Green Chemical Engineering (Grant No.2017-K09).

8 REFERENCES


21


(1).

Page 22 of 29

Hu, Z.; Deibert, B. J.; Li, J., Luminescent metal-organic frameworks for chemical sensing

and explosive detection. Chem. Soc. Rev. 2014, 43, 5815-5840. (2).

Xu, H.; Liu, F.; Cui, Y.; Chen, B.; Qian, G., A luminescent nanoscale metal-organic

framework for sensing of nitroaromatic explosives. Chem. Commun. 2011, 47, 3153-3155. (3).

Dong, M.; Wang, Y. W.; Zhang, A. J.; Peng, Y., Colorimetric and fluorescent

chemosensors for the detection of 2,4,6-trinitrophenol and investigation of their co-crystal structures. Chem. Asian J. 2013, 8, 1321-1330. (4).

Fu, H.-R.; Wu, X.-X; Ma, L.-F.; Wang, F.; Zhang J., Dual-Emission SG7@MOF sensor

via SC−SC transformation: Enhancing the formation of excimer emission and the range and sensitivity of detection. ACS Appl. Mater. Interfaces. 2018, 10, 18012-18020. (5).

Nagarkar, S. S.; Joarder, B.; Chaudhari, A. K.; Mukherjee, S.; Ghosh, S. K., Highly

selective detection of nitro explosives by a luminescent metal-organic framework. Angew Chem. Int. Ed. Engl. 2013, 52, 2881-2885. (6).

Qu, K.; Wang, J.; Ren, J.; Qu, X., Carbon dots prepared by hydrothermal treatment of

dopamine as an effective fluorescent sensing platform for the label-free detection of iron(III) ions and dopamine. Chemistry 2013, 19, 7243-7249. (7).

Yang, C. X.; Ren, H. B.; Yan, X. P., Fluorescent metal-organic framework MIL-53(Al) for

highly selective and sensitive detection of Fe3+ in aqueous solution. Anal. Chem. 2013, 85, 74417446.


22

Page 23 of 29 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


(8).

Zheng, M.; Tan, H.; Xie, Z.; Zhang, L.; Jing, X.; Sun, Z., Fast response and high sensitivity

europium metal organic framework fluorescent probe with chelating terpyridine sites for Fe(3+). ACS App.l Mater. Interfaces 2013, 5, 1078-1083. (9).

Cao, L. H.; Shi, F.; Zhang, W. M.; Zang, S. Q.; Mak, T. C., Selective Sensing of Fe(3+)

and Al(3+) Ions and Detection of 2,4,6-Trinitrophenol by a Water-Stable Terbium-Based MetalOrganic Framework. Chemistry 2015, 21, 15705-15712. (10).

Xu, H.; Hu, H. C.; Cao, C. S.; Zhao, B., Lanthanide organic framework as a regenerable

luminescent probe for Fe3+. Inorg. Chem. 2015, 54, 4585-4587. (11).

Xu, H.; Gao, J.; Qian, X.; Wang, J.; He, H.; Cui, Y.; Yang, Y.; Wang, Z.; Qian, G., Metal–

organic framework nanosheets for fast-response and highly sensitive luminescent sensing of Fe3+. J. Mater. Chem. A 2016, 4, 10900-10905. (12).

Li, B.; Wen, H. M.; Cui, Y.; Zhou, W.; Qian, G.; Chen, B., Emerging Multifunctional

Metal-Organic Framework Materials. Adv. Mater. 2016, 28, 8819-8860. (13).

Feng, M.-L.; Sarma, D.; Gao, Y.-J.; Qi, X.-H.; Li, W.-A.; Huang, X.-Y.; Kanatzidis, M.

G., Efficient ermoval of [UO2]2+, Cs+, and Sr2+ ions by radiation-rresistant gallium thioantimonates. J. Am. Chem. Soc. 2018, 140, 11133-11140. (14).

Zhang, L.; Kang, Z.; Xin, X.; Sun, D., Metal–organic frameworks based luminescent

materials for nitroaromatics sensing. CrystEngComm 2016, 18, 193-206. (15).

Tan, Y. X.; Wang, F.; Zhang, J., Design and synthesis of multifunctional metal–organic

zeolites. Chen. Soc. Rev. 2018, 47, 2130-2144.


23


(16).

Page 24 of 29

Nagarkar, S. S.; Desai, A. V.; Ghosh, S. K., A fluorescent metal-organic framework for

highly selective detection of nitro explosives in the aqueous phase. Chem. Commun. 2014, 50, 8915-8918. (17).

Liu, W.; Huang, X.; Xu, C.; Chen, C.; Yang, L.; Dou, W.; Chen, W.; Yang, H.; Liu, W., A

Multi-responsive Regenerable Europium-Organic Framework Luminescent Sensor for Fe(3+) , Cr(VI) Anions, and Picric Acid. Chemistry 2016, 22, 18769-18776. (18).

Sun, J.-Y.; Wang, L.; Zhang, D.-J.; Li, D.; Cao, Y.; Zhang, L.-Y.; Zeng, S.-L.; Pang, G.-

S.; Fan, Y.; Xu, J.-N.; Song, T.-Y., Construction of metal–organic coordination polymers derived from 4-substituted tetrazole–benzoate ligands: synthesis, structure, luminescence, and magnetic behaviors. CrystEngComm 2013, 15, 3402. (19).

Ilyushin, G. D.; Blatov, V. A., Combinatorial and topological modeling of cluster self-

assembly of the crystal structure of zeolites. Crystallography Reports 2015, 60, 453-465. (20).

Sheldrick, G., SHELXS version-2018/3 and SHELXL version-2018/3: programs for

crystal structure solution and refinement. University of Gottingen, Germany 2018. (21).

Sheldrick, G. M., Crystal structure refinement with SHELXL. Acta Crystallogr C Struct

Chem 2015, 71, 3-8. (22).

Huang, W. H.; Ren, J.; Yang, Y. H.; Li, X. M.; Wang, Q.; Jiang, N.; Yu, J. Q.; Wang, F.;

Zhang, J., Water-Stable Metal-Organic Frameworks with Selective Sensing on Fe(3+) and Nitroaromatic Explosives, and Stimuli-Responsive Luminescence on Lanthanide Encapsulation. Inorg. Chem. 2019, 58, 1481-1491.


24

Page 25 of 29 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


(23).

Xiao, J.; Liu, J.; Gao, X.; Ji, G.; Wang, D.; Liu, Z., A multi-chemosensor based on Zn-

MOF: Ratio-dependent color transition detection of Hg (II) and highly sensitive sensor of Cr (VI). Sens. Actuators, B 2018, 269, 164-172. (24).

Ma, A.; Wu, J.; Han, Y.; Chen, F.; Li, B.; Cai, S.; Huang, H.; Singh, A.; Kumar, A.; Liu,

J., Rational synthesis of a luminescent uncommon (3,4,6)-c connected Zn(ii) MOF: a dual channel sensor for the detection of nitroaromatics and ferric ions. Dalton Trans. 2018, 47, 9627-9633. (25).

Wang, W.; Xiao, Z.; Lin, H.; Wang, R.; Zhang, L.; Sun, D., Synthesis, structure, and

properties of a 3D porous Zn(II) MOF constructed from a terpyridine-based ligand. RSC Advances 2016, 6, 16575-16580. (26).

Shustova, N. B.; McCarthy, B. D.; Dincă, M., Turn-On Fluorescence in

Tetraphenylethylene-Based Metal–Organic Frameworks: An Alternative to Aggregation-Induced Emission. J. Am. Chem. Soc. 2011, 133, 20126-20129. (27).

Sohn, H.; Sailor, M. J.; Magde, D.; Trogler, W. C., Detection of Nitroaromatic Explosives

Based on Photoluminescent Polymers Containing Metalloles. J. Am. Chem. Soc. 2003, 125, 38213830. (28).

Xing, S.; Bing, Q.; Qi, H.; Liu, J.; Bai, T.; Li, G.; Shi, Z.; Feng, S.; Xu, R., Rational Design

and Functionalization of a Zinc Metal-Organic Framework for Highly Selective Detection of 2,4,6Trinitrophenol. ACS Appl. Mater. Interfaces 2017, 9, 23828-23835. (29).

Li, L.-S.; Wang, X.; Jia, Y.-Y.; Xu, S.-X.; Yu, M.-H.; Zhang, Y.-H., A Hexanuclear

Cadmium Metal-Organic Framework Exhibiting Dual Mechanisms to Trigger a FluorescenceQuenching Response toward Iron(III) Ions. Eur. J. Inorg. Chem. 2018, 2018, 1068-1072.


25


(30).

Page 26 of 29

Mukherjee, S.; Desai, A. V.; Manna, B.; Inamdar, A. I.; Ghosh, S. K., Exploitation of Guest

Accessible Aliphatic Amine Functionality of a Metal–Organic Framework for Selective Detection of 2,4,6-Trinitrophenol (TNP) in Water. Cryst. Growth Des. 2015, 15, 4627-4634. (31).

Shi, Z. Q.; Guo, Z. J.; Zheng, H. G., Two luminescent Zn(II) metal-organic frameworks

for exceptionally selective detection of picric acid explosives. Chem. Commun. 2015, 51, 83008303. (32).

Wan, K.-K.; Yu, J.-H.; Xu, J.-Q., 4,5-Diamino-1,2-dihydropyridazine-3,6-dione-based

layered Zn2+ coordination polymer and sensing properties on 2,4,6-trinitrophenol and Cr2O7. J. Solid State Chem. 2019, 270, 212-218. (33).

Wang, T.; Huang, K.; Peng, M.; Li, X.; Han, D.; Jing, L.; Qin, D., Metal–organic

frameworks based on tetraphenylpyrazine-derived tetracarboxylic acid for electrocatalytic hydrogen evolution reaction and NAC sensing. CrystEngComm 2019, 21, 494-501. (34).

Rachuri, Y.; Parmar, B.; Bisht, K. K.; Suresh, E., Mixed ligand two dimensional

Cd(ii)/Ni(ii) metal organic frameworks containing dicarboxylate and tripodal N-donor ligands: Cd(ii) MOF is an efficient luminescent sensor for detection of picric acid in aqueous media. Dalton Trans. 2016, 45, 7881-7892. (35).

Li, J.; Yang, G.; Hou, L.; Cui, L.; Li, Y.; Wang, Y. Y.; Shi, Q. Z., Three new solvent-

directed 3D lead(II)-MOFs displaying the unique properties of luminescence and selective CO2 sorption. Dalton Trans. 2013, 42, 13590-13598.


26

Page 27 of 29 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


(36).

Zhao, S.; Lv, X.-X.; Shi, L.-L.; Li, B.-L.; Wu, B., An unusual (4,4)-connected 3D porous

cadmium metal–organic framework as a luminescent sensor for detection of nitrobenzene. RSC Advances 2016, 6, 56035-56041. (37).

Song, X.-Z.; Song, S.-Y.; Zhao, S.-N.; Hao, Z.-M.; Zhu, M.; Meng, X.; Wu, L.-L.; Zhang,

H.-J., Single-Crystal-to-Single-Crystal Transformation of a Europium(III) Metal-Organic Framework Producing a Multi-responsive Luminescent Sensor. Adv. Funct. Mater. 2014, 24, 4034-4041. (38).

Tang, Q.; Liu, S.; Liu, Y.; Miao, J.; Li, S.; Zhang, L.; Shi, Z.; Zheng, Z., Cation sensing by

a luminescent metal-organic framework with multiple Lewis basic sites. Inorg. Chem. 2013, 52, 2799-2801. (39).

Dang, S.; Ma, E.; Sun, Z.-M.; Zhang, H., A layer-structured Eu-MOF as a highly selective

fluorescent probe for Fe3+ detection through a cation-exchange approach. J. Mater. Chem. 2012, 22, 16920. (40).

Buragohain, A.; Yousufuddin, M.; Sarma, M.; Biswas, S., 3D Luminescent Amide-

Functionalized Cadmium Tetrazolate Framework for Selective Detection of 2,4,6-Trinitrophenol. Cryst. Growth Des. 2016, 16, 842-851.


27


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For Table of Contents Use Only A Novel Multi-functional Zn-MOF Fluorescent Probe Demonstrating Unique Sensitivity and Selectivity for Detection of PA and Fe3+ Ions in Water Solution Xinrui Zhuang,† Xiao Zhang,* † Nanxi Zhang,§ Yan Wang,† Liyan Zhao,† Qingfeng Yang,// † MIIT key laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150080, People’s Republic of China. § School of Life Science and Technology, Harbin Institute of Technology, Harbin, 150080, People's Republic of China. // State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical, Engineering, Ningxia University, Yinchuan, 750021, China

Novel MOF {Zn2(tpt)2(tad)2·H2O} with a 3-fold interpenetrating 3D framework was developed for highly sensitive and selective detection of PA and Fe3+. The fluorescence test plates and the recyclability further increased its application potential.


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A novel metal organic framework {Zn2(tpt)2(tad)2•H2O} (1) with a 3-fold interpenetrating 3D framework was successfully synthesized under hydrothermal condition.It displays highly sensitively and selectively property for PA and Fe3+ ions. The fluorescence test plates and the recyclability further increased its application potential. 79x25mm (600 x 600 DPI)


A Novel Multi-functional Zn-MOF Fluorescent Probe Demonstrating

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