Novel Fluorescence Sensor Based on All-Inorganic Perovskite

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Functional Inorganic Materials and Devices

Novel Fluorescence Sensor Based on All-Inorganic Perovskite Quantum Dots Coated with Molecularly Imprinted Polymers for Highly Selective and Sensitive Detection of Omethoate Shuyi Huang, Manli Guo, Jiean Tan, Yuanyuan Geng, Jinyi Wu, Youwen Tang, Chaochin Su, Chun Che Lin, and Yong Liang ACS Appl. Mater. Interfaces, Just Accepted Manuscript • DOI: 10.1021/acsami.8b14472 • Publication Date (Web): 22 Oct 2018 Downloaded from http://pubs.acs.org on October 22, 2018

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ACS Applied Materials & Interfaces

Novel Fluorescence Sensor Based on All-Inorganic Perovskite Quantum Dots Coated with Molecularly Imprinted Polymers for Highly Selective and Sensitive Detection of Omethoate Shuyi Huang,a Manli Guo,a Jiean Tan,a Yuanyuan Geng,a Jinyi Wu,a Youwen Tang,*,a Chaochin Su,c,d Chun Che Lin,*,b,c,d and Yong Liang*,a aSchool

of Chemistry and Environment, South China Normal University, 510631 Guangzhou, China.

bGraduate

Institute of Nanomedicine and Medical Engineering and International Ph.D. Program in

Biomedical Engineering, College of Biomedical Engineering, Taipei Medical University, Taipei 110, Taiwan. cInstitute

of Organic and Polymeric Materials, National Taipei University of Technology, Taipei 10608,

Taiwan. dResearch

and Development Center for Smart Textile Technology, National Taipei University of Technology,

Taipei 10608, Taiwan. KEYWORDS: inorganic perovskites, CsPbBr3, molecular imprinting, fluorescent sensor, omethoate

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ABSTRACT: All-inorganic cesium lead halide perovskites (CsPbX3, X = Cl, Br, I) have attracted considerable attention with superior electrical and photophysical properties. In the study, luminescent perovskite (CsPbBr3) quantum dots (QDs) as sensing elements combined with molecularly imprinted polymers (MIPs) are used for the detection of omethoate (OMT). The new MIPs@CsPbBr3 QDs were synthesized successfully through the imprinting technology with a sol-gel reaction. The fluorescence of the MIPs@CsPbBr3 QDs was quenched obviously on loading the MIPs with OMT, the linear range of OMT was from 50 ng/mL to 400 ng/mL, and the detection limit was 18.8 ng/mL. The imprinting factor (IF) was 3.2, which indicated excellent specificity of the MIPs for the inorganic metal halide (IMH) perovskites. The novel composite possesses the outstanding fluorescence capability of CsPbBr3 QDs and the high selectivity of molecular imprinting technology, which can convert the specific interactions between template and the imprinted cavities to apparent changes in the fluorescence (FL) intensity. Thence, a selective and simple fluorescence sensor for direct and fast detection of organophosphorus (OP) pesticide in vegetable and soil samples were developed here. The present work also illustrates the potential of IMH perovskites for sensor applications in biological and environmental detection.

■ INTRODUCTION In the last few decades, photoluminescence semiconductor quantum dots have attracted enormous interest mainly owing to their several elegant properties, such as good photostability, tunable emission wavelength, narrow symmetric emission, and broad absorption spectra.1 Due to those attractive optical properties, the QDs have found promising applications in light-emitting diodes (LEDs), solar cells, biological imaging, and especially in sensors.2 Molecularly imprinted polymers (MIPs) were employed so as to improve selectivity of QD-based sensors. Such the MIP@QDs composites were served as fluorescence sensors for detecting analytes selectively. Molecular imprinting is a well-established technology to create the particular template-shaped cavities, which have the special functional groups, size, and shape of the template molecules.3 Due to the strong affinity, high specific selectivity, easy preparation and low cost,4 MIPs have been widely exploited in many


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significant application fields, such as bionic sensor, solid-phase extraction and chromatographic separation, catalysis, drug-controlled release, and chemical analysis.5 Till present, a large amount of MIPs-capped QDs sensors, possessing the sensitivity of QDs and selectivity of MIPs, have been exploited for the detection of different compounds, for example cytochrome c,6 4-nitrophenol,7 pyrethroids,8 melamine,9 and ractopamine.10 Now, the common quantum dots which are used as fluorescent sensor are generally composed of IV, II-VI, IV-VI or III-V elements, such as CdSe,11 CdTe,12 CdS, Si, C,13 and ZnS quantum dots. However, these quantum dots as a sensing element have a drawback that the sensor sensitivity becomes lowered owing to the low quantum yield of the QDs. Thus, it is highly necessary to develop novel semiconductor quantum dots with excellent photoluminescence properties and high fluorescence quantum yield. Recently, perovskites with formula ABX3 (where A = Cs+, CH3NH3+; B = Pb, Sn, and Ge; X = Cl–, Br–, and/or I–) have already attracted substantial attention and shown immense potential in many areas,14 such as solar cells,15-17 photovoltaics,18,19 LEDs,20,21 and lasers,22,23 due to their high emission efficiencies, easily tunable optical bandgap, and excellent charge transport characteristics.24 Perovskites materials with some of these advantages had already been achieved in various forms, including nanowires, thin films, nanotubes, and quantum dots.25 In the past two years, perovskite QDs have become a new member of the "quantum dot family", such as IMH perovskites quantum dots (CsBX3, B = Pb, Sn, Ge; X = Cl, Br, I), have combined the advantages of both halide perovskites and the QDs.26 Compared to the organic–inorganic metal halide (OMH) perovskites, IMH perovskites show higher stability and higher photoluminescence quantum yields (PLQYs), as indicated by over 90% PLQYs for green fluorescence CsPbBr3 QDs.27,28 IMH perovskites are a type of growth potential novel quantum dot materials. Until now, plenty of the all-inorganic perovskite QDs have been prepared mainly through colloidal synthetic approaches, viz. anion exchange, hot-injection, ultrasonication, and room-temperature reprecipitation.29 Kovalenko et al. were the first group to synthesize IMH perovskite QDs.30 Recently, a room 3 ACS Paragon Plus Environment


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temperature approach for synthesis of CsPbX3 nanocrystals (NCs), was reported by Zeng and co ‐workers.31 Urban et al. developed a simple ultrasonication method to prepare colloidal CsPbX3 perovskite NCs.32 These perovskite NCs showed that outstanding photophysical properties, including narrow emission width, size- and composition-controlled photoluminescence property, and long fluorescence lifetime. Despite the high brightness and high PLQYs of the perovskite NCs, the stability of CsPbX3 NCs in the presence of oxygen and water is still a significant trouble. In order to ameliorate the stability of CsPbX3 NCs, a simple strategy is to modify the surface of CsPbX3 NCs with another stable material. For instance, Fu and co-workers in order to reduce vulnerabilities on perovskite surface, they embedded CsPbX3 NCs within microhemispheres of waterresistant polystyrene matrix.33 Li’s group incorporated CsPbBr3 NCs into a SiO2/Al2O3 monolith, successfully improved their stability.34 Zhang et al. used (3-aminopropyl)triethoxysilane (APTES) as both the precursor for a silica matrix and the capping agent for IMH perovskite QDs to protect delicate perovskite QDs.35 However, there is no report that the application of IMH perovskites QDs combined with MIPs for analysis and detection. In this regard, we attempted to develop a new MIPs-capped CsPbBr3 QDs sensor which would possess the high selectivity of MIPs and high PLQYs of CsPbBr3 QDs. In the present work, we designed and prepared a novel MIP@CsPbBr3 QDs sensor for highly sensitive and specific recognition of template molecule for the first time. First, we used (3-aminopropyl) triethoxysilane (APTES) to synthesize the APTES-capped CsPbBr3 QDs by the one-pot approach. The APTES-capped CsPbBr3 QDs were chosen as a fluorescent carrier, OMT was chosen as a template molecule, and the crosslinker is tetramethylorthosilicate (TMOS). Through sol-gel process, excess APTES was simultaneously used as a functional monomer, which with the template omethoate by the non-covalent interaction. When the template was removed via solvent extraction, the resultant MIP@CsPbBr3 QDs composites showed selective recognition ability toward the corresponding template. The prepared MIP@CsPbBr3 QDs composites fluorescence sensor for OMT was investigated and characterized carefully, and its recognition properties were

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well demonstrated. The obtained sensor has applied successfully in the detection of OMT for vegetables and soil samples.

Figure 1. Schematic representation of the MIPs@CsPbBr3 QDs sensor. ■ RESULTS AND DISCUSSION

Preparation and Characterization of APTES-capped CsPbBr3 QDs. The fabrication process of MIPs@CsPbBr3 QDs composites was showed in Figure 1. We used a facile method to synthesize APTEScapped CsPbBr3 QDs by adding APTES directly into the solution of Cs2CO3, OA, and PbBr2 in one step. APTES underwent hydrolysis by the traces of moisture present in the air and formed a protective cover on the perovskite QDs surface. A silica matrix was gradually formed for protecting perovskite QDs by this way. 5 ACS Paragon Plus Environment


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What's more, silica forms an ideal coating to protect fluorescent quantum dot because of its inert and optically transparent. The OA-capped CsPbBr3 QDs had carboxylic groups which could interact with TMOS and APTES to eventually form sol-gel MIP-coated QDs. Through hydrogen bonding, the APTES possesses an amino group can interact with the hydroxyl, amino, and carboxylic groups of omethoate. In molecular imprinting process, there is the non-covalent interaction between omethoate and APTES.36 At an excitation of 365 nm, both the synthesized MIP@CsPbBr3 QDs and NIP@CsPbBr3 QDs exhibited a symmetric emission at 510 nm. The APTES-capped CsPbBr3 QDs have a green and narrow emission peak at 512 nm (Figure 2a) with a full-width at half-maximum (FWHM) of 34 nm. When excitation at 365 nm, the absolute PLQYs of APTEScapped CsPbBr3 QDs was measured at 92% which was much higher than that of the representative organic dye Rhodamine 6G (about 54%) and CdSe/CdS-ZnS QDs (about 65%).37 The low PLQYs of traditional QDs can be attributed to their mid-gap states, however, the high PLQYs may be from negligible electron or hole trapping pathways in CsPbBr3 QDs, by transient absorption spectroscopy studies.38 The time-resolved PL decay spectra (double-exponential decay function) of the APTES-capped CsPbBr3 QDs has been presented in Figure 2b. The average PL decay lifetimes was 40.8 ns for APTES-capped CsPbBr3 QDs.39 Energy dispersive X-ray (EDX) spectroscopy spectra of the APTES-capped CsPbBr3 QDs are shown in Figure S1. The presence of Cs, Br, Pb, O, N, and Si indicated that the QDs were completely capped within the SiO2.


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Figure 2. Luminescence and structure characterization of APTES-capped CsPbBr3 QDs. (a) UV-visible absorption and PL emission spectra of the APTES-capped CsPbBr3 QDs solution. Inset figure: Stable and bright luminescence of APTES-capped CsPbBr3 QDs solution. (b) The time-resolved PL decay spectra of APTES-capped CsPbBr3 QDs at excitation of 365 nm. (c) X-ray diffraction patterns of (I) pure SiO2, (II) APTES-capped CsPbBr3 QDs, and (III) MIPs@CsPbBr3 QDs composites. (d) FT-IR spectra of (I) CsPbBr3 QDs, (II) APTES-capped CsPbBr3 QDs, and (III) MIPs@CsPbBr3 QDs composites.

Figure 2c shows the X-ray diffraction (XRD) patterns of pure SiO2, APTES-capped CsPbBr3 QDs, and MIPs@CsPbBr3 QDs composites. Owing to an amorphous structure SiO2, it has a broad peak at 2θ = 20° − 25°.40 The XRD patterns of APTES-capped CsPbBr3 QDs (II) and MIPs@CsPbBr3 QDs (III) composites indicated a cubic zinc blende structure with peaks at (100), (110), (200), (211), and (220) planes. The intensities of the diffraction peaks of APTES-capped CsPbBr3 QDs were stronger than those of MIPs@CsPbBr3 QDs composites. It means that more silica materials cover the surface of MIPs@CsPbBr3 QDs composites. The FT-



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IR spectrum of CsPbBr3 QDs (Figure 2d, I) showed characteristic peaks at 1,716 cm−1 which corresponded to the CO stretching vibration of the carboxylic group. Compared to the infrared data of CsPbBr3 QDs, the FTIR spectrum of APTES-capped CsPbBr3 QDs (Figure 2d, II) exhibited characteristic peaks of a Si-O-Si asymmetric stretching at 1,074 cm−1, an absorption band at 1,625 cm−1 consistent with the -NH stretching of amino groups, and a weak band at 947 cm−1 (Si-OH) confirmed a wrapped silica layer was formed after the hydrolysis condensation of APTES. The FT-IR spectrum of MIPs@CsPbBr3 QDs (Figure 2d, III) was similar to the APTES-capped CsPbBr3 QDs. The spectrum showed absorption peaks at 454 and 790 cm−1 corresponding to Si-O vibrations, and band at 1,080 cm−1 suggested the existence of Si-O-Si asymmetric stretching. Another absorption peak observed at 3,321 cm−1 was the -OH stretching. TEM micrographs of pure CsPbBr3 QDs (Figure 3a) revealed that the QDs had good dispersion. The HRTEM images illustrated that the pure CsPbBr3 QDs were cubic shaped with a diameter ranging from 8 to 16 nm (Figure 3b). Figure 3b emphasizes that the well-aligned crystalline structure of CsPbBr3 QDs with a cubic lattice parameter of 0.32 nm. After APTES hydrolysed on the QDs surface (Figure 3c), gradually the process aggregated and embedded the pure QDs into SiO2 material. The diameter of the CsPbBr3@SiO2 particles was 30 nm. On comparing with the original CsPbBr3@SiO2, it became apparent that the diameter of the CsPbBr3@SiO2 particles increased significantly to 200 nm after coating with MIP, which demonstrated that the MIP@CsPbBr3 QDs composites (Figure 3d) probably had more shape-specific cavities, because a large surface area can combine more template molecules.


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Figure 3. (a) TEM images of pure CsPbBr3 QDs. HRTEM images of (b) pure CsPbBr3 QDs, (c) CsPbBr3@SiO2, and (d) MIPs@CsPbBr3 QDs composites.

Influence of the cross-linker TMOS amount and molar ratio of template to functional monomer. In order to improve the sensitivity and obtain the appropriate adsorption time, the amount of cross-linker TMOS, and molar ratio of template to functional monomer were investigated and optimized, and the results are shown in Figure S2. After the template was adsorbed on the MIPs@CsPbBr3 QDs, the quenching fluorescence of the QDs was observed. The reason for such observation was possibly because omethoate changed the surface state of CsPbBr3 QDs effectively which increase surface defects and non-radiative recombination, thereby resulting



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in quenching of the fluorescence of CsPbBr3 QDs. The fluorescence quenching in this system followed the Stern−Volmer equation as shown: F0/F = 1 + KSVCq where F is the fluorescence intensity in the presence of analyte, F0 is the initial fluorescence intensity in the absence of quencher, Cq is the concentration of the quencher, and KSV is the quenching constant of the quencher. To evaluate the specific recognition ability of the materials, we defined an imprinting factor (IF) = KSV,MIP/KSV,NIP.41 Effects of different solvents, incubation time, and temperature. The FL of MIP@CsPbBr3 QDs before removal of the template (Figure 4a, I) was significantly lower than that of MIP@CsPbBr3 QDs composites without the template. After the removal of template (Figure 4a, II), the FL of MIP@CsPbBr3 QDs composites significantly increased to nearly the similar FL intensity as NIP@CsPbBr3 QDs (Figure 4a, III). It can be considered that the omethoate of the imprinted polymer was removed substantially. We further studied the effects of different polar organic solvents on the properties of MIP@CsPbBr3 QDs composites (Figure 4b and 4c). It can be clearly seen from the figures, in nonpolar solvents (e.g. hexane, toluene, and dichloromethane), the MIP@CsPbBr3 QDs composites solutions displayed bright characteristic fluorescence peaks.37 However, compared to most quantum dots, the CsPbBr3 QDs were easily decomposed in lots of ordinary solvents, particularly in polar solvents (i.e., DMF and ethanol), because perovskites QDs are fully ionic crystals.20 So, considering the toxicity of toluene and the subsequent sample extraction process, we selected dichloromethane as the detection solvent. Moreover, we were also studied the effect of incubation time and temperature to guarantee that the omethoate and imprinted polymer are combined completely, as depicted in Figure S3 and Figure S4.


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Figure 4. (a) Fluorescence spectra of MIP@CsPbBr3 QDs composites before (I) and after (II) the removal of the template; (III) NIP@CsPbBr3 QDs composites. (b) Effect of solvent on optical properties of MIP@CsPbBr3 QDs composites. The solvent sequence is as follows: (1) Hexane, (2) Toluene, (3) Dichloromethane, (4) Ethyl acetate, (5) Trichloromethane, (6) Acetonitrile, (7) N,N-Dimethylformamide (DMF), and (8) Ethanol (Polarity increases from left to right). (c) Fluorescence spectra of MIP@CsPbBr3 QDs composites in different polar organic solvents.

Photostability. Under continuous UV-light irradiation, we investigated a photostability test of APTES-capped CsPbBr3 QDs and MIPs@CsPbBr3 QDs composites. As depicted in Figure 5a, after 96 h illumination, the APTES-capped CsPbBr3 QDs solution has some green precipitates at the bottom, which may be due to the further hydrolysis of APTES. On the contrary, the MIPs@CsPbBr3 QDs composites solution was still green probably because the APTES-capped CsPbBr3 QDs have been covered by MIP. Furthermore, we can observe the obvious fluorescence enhancement of both solutions in the first 1-2 hours of UV irradiation (Figure 5b),



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which is called “photoactivation” phenomenon. Some studies suggest that UV irradiation can solidify the surface defects of quantum dots, resulting in fluorescence enhancement.43 With continuous light irradiation, the FL intensities of both samples continuously decreased, probably due to photo-oxidation. However, after 96 h, the remnant fluorescence of the MIPs@CsPbBr3 QDs composites solution maintained a higher PLQYs of 81%, but the APTES-capped CsPbBr3 QDs solution was reduced to 56%. Evidently, the fluorescence decline rate of the MIPs@CsPbBr3 QDs composites was much slower than that of the APTES-capped CsPbBr3 QDs. Thus, during UV light illumination, we inferred that the imprinted polymer shell can protects the quantum dots from photo-oxidation.

Figure 5. (a) Photostability test with UV light (365 nm, 24W) and the optical pictures of the cuvettes containing the APTES-capped CsPbBr3 QDs solution (left) and MIPs@CsPbBr3 QDs composites (right) solutions. (b) A function of remnant florescence intensity and illumination time. Recognition ability. Then, we investigated the fluorescence change of MIP@CsPbBr3 QDs and NIP@CsPbBr3 QDs composites after recognition with different concentrations of omethoate. After recognition with omethoate, both MIP@ and NIP@CsPbBr3 QDs composites (Figure 6a and b) show fluorescence quenching. It is worth noting that the fluorescence quenching degree of MIP@CsPbBr3 QDs materials were greater. Due to the presence of imprinting cavities in MIP@CsPbBr3 QDs composites, they have a highly 12 ACS Paragon Plus Environment

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specific binding toward omethoate, resulting in the higher quenching efficiency or better sensitivity of MIP@CsPbBr3 QDs composites. In the range of 50 to 400 ng/mL, both the calibration plots of (F0/F−1) versus Cq for MIP@CsPbBr3 QDs composites and NIP@CsPbBr3 QDs composites displayed a good linear, and the correlation coefficients of 0.997 and 0.991, were shown in the insets of Figure 6a and b. The detection limit of MIP@CsPbBr3 QDs composites for OMT was 18.8 ng/mL. The limit of detection was calculated on following 3σ IUPAC criteria (3σ/S), where σ was the standard deviation of the blank signal and S was the slope of the linear calibration. For the detection of 300 ng/mL OMT, the RSD was 1.7% (9 batches). The IF was calculated to be 3.2 under optimum conditions, indicating that the specificity and the FL quenching efficiency largely enhanced for the MIP@CsPbBr3 QDs composite towards template molecule after the imprinting recognition.



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Figure 6. Effect of different concentrations of omethoate (50-400 ng/mL) on the fluorescence spectra of (a) MIP@CsPbBr3 QDs composites and (b) NIP@CsPbBr3 QDs composites; Insets of (a) and (b) represent SternVolmer plots of MIP@CsPbBr3 QDs composites and NIP@CsPbBr3 QDs composites with OMT. (c) Selectivity of MIP@CsPbBr3 QDs composites and NIP@CsPbBr3 QDs composites for omethoate over its analogs, including dimethoate, dichlorvos, phoxim, chlorpyrifos, and acetamiprid (300 ng/mL). (d) Chemical structures of omethoate, dimethoate, dichlorvos, phoxim, chlorpyrifos, and acetamiprid.

Selectivity and reproducibility. To evaluate the selectivity of MIP@CsPbBr3 QDs composites, several similar organophosphorus insecticides, such as dimethoate, dichlorvos, phoxim, chlorpyrifos, and acetamiprid (organochlorine pesticide) were tested. The selectivity factor (γ) was used to evaluate the selectivity of the imprinted polymer (Table S1). The higher γ value means that the poorer selectivity of MIP@CsPbBr3 QDs composites for the analogs. Among all the chosen organophosphorus pesticides, on account of the specific imprinted cavities were completely match to OMT with respect to functional groups, shape, and size, and then MIP@CsPbBr3 QDs composites that showed the highest fluorescence quenching efficiency toward OMT, as shown in Figure 6c. Additionally, when the MIP@CsPbBr3 QDs composites were used to detect dimethoate, the γ is 1.16 because its structure was the most closely to that of the template. It indicated that part of the dimethoate can enter the imprinting cavities of OMT. Moreover, the MIP@ and NIP@CsPbBr3 QDs composites exhibited much lower responses toward dichlorvos, phoxim, chlorpyrifos, and acetamiprid. In comparison with OMT, other pesticides had different structures, and thus, could not go inside the recognition cavities of MIP@CsPbBr3 QDs composites. Assuredly, because of the nonspecific adsorption, polymers have the relatively weak responses. These results signified that MIP@CsPbBr3 QDs composites had high specificity to omethoate. 14 ACS Paragon Plus Environment

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The reproducibility of MIPs@CsPbBr3 QDs composites was investigated using seven batches of MIPs@CsPbBr3 QDs composites prepared at different times, and each batch was tested in triplicate. The fluorescence response results toward OMT are displayed in Figure S5, which indicates that reproducibility of MIPs@CsPbBr3 QDs composites are satisfactory, with an RSD less than 3.9 % between all the samples. Possible mechanism of the fluorescence quenching effect. Quenching is any process that reduces the fluorescence intensity of a luminescent material, and fluorescence quenching includes dynamic quenching and static quenching. During dynamic quenching, the fluorescent substance in excited state collides with the quencher molecule, returns to the ground state because they lost their excitation energy. Dynamic quenching can be achieved by an energy transfer mechanism or a charge transfer mechanism. The mechanism of fluorescence quenching effect was investigated by UV-visible absorption (red line) and PL emission (blue line) spectra. Figure 7a shows that between the emission spectrum of the MIPs@CsPbBr3 QDs composites (510 nm) and the absorption spectrum of the OMT (270 nm), there is no spectral overlap, so the probability of energy transfer is FL quenching mechanism is very small. To understand the quenching dynamics, the time-resolved FL decay curves were investigated. Figure 7b shows that the MIPs@CsPbBr3 QDs composites lifetime is dramatically decreased in the presence of OMT. The average lifetime is shorted from 27.8 ns to 23.8 ns after adding OMT (fluorescence lifetime data are calculated by biexponential fit model). During the recognition process, through hydrogen bonding, the template molecule can interact with the functional monomer APTES(-NH2), causing the average fluorescence lifetime of the MIPs@CsPbBr3 QDs composites to change. This interaction could bring the OMT very close to the CsPbBr3 QDs resulting in fluorescence quenching. Since the charge separation and exciton diffusion are very efficient in perovskites, maybe relate to charge


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transfer from the QDs to OMT. It is highly suspected to provide a major pathway to the fluorescence quenching.

Figure 7. (a) UV-visible absorption of omethoate and PL emission spectra of the MIPs@CsPbBr3 QDs composites. (b) The time-resolved PL decay spectrum of MIPs@CsPbBr3 QDs composites in the absence (red line) and presence (black line) of OMT.

Analysis and detection of OMT in real samples. The MIP@CsPbBr3 QDs composites were used to detect the level of omethoate residue in soils and cabbages purchased from a local market, so as to assess the practicability of this sensor. Omethoate was not found after sample extraction process, so we used the spiked samples for the recovery experiment. The results were shown in Table S2, the recoveries of OMT were in the range of 96.7–101% with RSDs below 4.2% for cabbage samples, and 81.4−88.4% with RSDs below 4.3% for soil samples. After that, omethoate was sprayed onto the cabbage, the residues of omethoate in the sprayed cabbage after 1 day, 7 days, and 15 days were detected using the MIPs@CsPbBr3 QDs sensor, and the results have been presented in Table S3. These results demonstrated that the method provides well repeatability and accuracy, meanwhile, it was trustworthy and pragmatic for the detection of pesticides in real


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samples. In short, the sensitivity of the newly developed QD sensor can meet the requirements for direct detection of OMT residues in agricultural products. Compared to the other omethoate detection methods (Table S4), the detection limits of fluorescence analysis method described in the current paper reached the present level of chromatographic technology. Additionally, compared to HPLC or GC-MS method, the fluorescence detection method does not require complicated sample pretreatment, long processing time, and plenty solvent waste, and our suggested method has high selective and highly sensitivity to detect omethoate. ■ CONCLUSIONS

In summary, the first reported MIP fluorescence sensor based on CsPbBr3 QDs from the inorganic hybrid perovskites, which combined well the high PL quantum yields of CsPbBr3 QDs and the high selectivity of molecularly imprinted polymers and showed a high sensitivity toward OMT assays. We synthesized successfully a MIP@CsPbBr3 QDs sensor allowed determination of OMT with concentration as low as 18.8 ng/mL. The present work illustrates that the immense potential of all-inorganic perovskites as sensors in biological and environmental detection. As is known all that perovskites are not stable in water, a water-soluble perovskite is a challenging task, and our current work is focus on improving the stability of perovskites and synthesize water-soluble perovskites quantum dots because they would open up possibilities for biological fields. ■ METHODS

Synthesis of CsPbBr3 QDs and APTES-capped CsPbBr3 QDs. The QDs were synthesized according to previous reports.35 Briefly, adding three kinds of materials (12 mL ODE, 1 mL OA and 0.32 g Cs2CO3) into the flask, which was deaerated by N2, then at 150 °C until the solids were


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completely dissolved. Next, 0.188 mmol PbBr2 and 5 mL ODE were added into another flask, which was deaerated by N2 and at 120 °C maintain stirring for 1h, and then quickly added 100 μL OAm, 500 μL APTES, and 100 μL OA under N2 protection. After half hour, the matrix is increased to 170 ºC, and 700 μL Cs oleate solution (preheated to 100 ºC) was quickly added into it. Immediately, the reaction was put into an ice water bath to form quantum dots. Then, the reaction was exposed to air and stirred to form SiO2. Next, the SiO2@QDs composite was centrifuged at 9000 rpm for 8 min and washed twice by hexane. Finally, the APTES-capped CsPbBr3 QDs solution was dispersed in n-hexane for preservation. The CsPbBr3 QDs was synthesized without addition of APTES. Synthesis of MIPs@CsPbBr3 QDs composites. 1 mmol omethoate (template), 10 mL ODE and the excess (3-aminopropyl) triethoxysilane (APTES) in the previous step was used as a functional monomer, 50 μL APTES-capped CsPbBr3 QDs were added into a 25 mL flask and stirred for half hour. And then, 100 μL cross-linking monomer-TMOS was added, and the reaction was sealed and stirred at room temperature for 12 hours. TMOS was chosen as the cross-linker because it has a faster rate of hydrolysis compared to TEOS, so it could consume more water under the same conditions. The non-imprinted polymer (NIP) was synthesized in the same way except that no OMT (template) was added. The resultant MIP@ and NIP@CsPbBr3 QDs were centrifuged and washed 10 times with ethyl: hexane acetate = 1:3 mixed solvent to get almost the similar fluorescence intensity of MIP and NIP. At last, the precipitate of MIP@CsPbBr3 QDs were redispersed in dichloromethane and stored at 4 ºC. Characterizations. UV-2700 UV-visible Spectrophotometer (Shimadz, Japan). F-2700 fluorescence spectrometer (Hitachi, Japan). Bruker D8 Advance X-ray diffractometer (Bruker,


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Germany). Spectrum Two FT-IR Spectrometer (Perkinelmer, USA). JEM-1400 PLUS Transmission Electron Microscope (Hitachi, Japan). JEM-2100HR (HRTEM, JEOL, Japan).

■ ASSOCIATED CONTENT Supporting Information. The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acsami.XXXXXX. All the reagents. EDX spectra of APTES-capped CsPbBr3 QDs. Incubation time and temperature optimization of MIPs@CsPbBr3 QDs composites. Table showing: imprinting factors of MIPs@CsPbBr3 QDs composites for the omethoate and its analogs; Recoveries and RSD values from spiked vegetable and soil samples; OMT residues in sprayed cabbages; Comparison with other omethoate detection methods reported. (PDF) ■ ABBREVIATIONS IMH, luminescent all-inorganic metal halide; QDs, quantum dots; OMT, omethoate; IF, imprinting factor; OP, organophosphorus; FL, fluorescence; LEDs, light-emitting diodes; MIPs, Molecularly imprinted polymers; NIPs, Non-imprinted polymers; OMH, organic–inorganic metal halide; PLQYs,

photoluminescence

quantum

yields;

NCs,

nanocrystals;

APTES,

(3-

aminopropyl)triethoxysilane; TMOS, tetramethylorthosilicate; FWHM, full-width at halfmaximum; EDX, Energy dispersive X-ray; XRD, X-ray diffraction. ■ AUTHOR INFORMATION Corresponding Authors


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*Email: [email protected] (Y.L.). *Email: [email protected] (Y.-W.T). *Email: [email protected] (C.C.L). ORCID Chun Che Lin: 0000-0001-9261-2482 Author Contributions All authors contributed to the discussion and writing of the manuscript. The final version was approved by all authors. Notes The authors declare no competing financial interest.

■ ACKNOWLEDGMENT This work was supported by National Natural Science Foundation of China (No. 51478196 and No. 21275057), the Science and Technology Plan Project of Guangdong Province (No: 2017A020212003) and the Ministry of Science and Technology of Taiwan (Contract no. MOST 107-2113-M-027-004).

■ REFERENCES (1) Liu, H.; Fang, G.; Li, C.; Pan, M.; Liu, C.; Fan, C.; Wang, S. Molecularly Imprinted Polymer on Ionic Liquid-Modified CdSe/ZnS Quantum Dots for the Highly Selective and Sensitive Optosensing of Tocopherol. J. Mater. Chem. 2012, 22, 19882-19887. (2) Owen, J.; Brus, L. Chemical Synthesis and Luminescence Applications of Colloidal Semiconductor Quantum Dots. J. Am. Chem. Soc. 2017, 139, 10939-10943. (3) Li, D. Y.; He, X. W.; Chen, Y.; Li, W. Y.; Zhang, Y. K. Novel Hybrid Structure Silica/CdTe/Molecularly Imprinted Polymer: Synthesis, Specific Recognition, and Quantitative Fluorescence Detection of Bovine Hemoglobin. ACS Appl. Mater. Interfaces 2013, 5, 1260912616.


20

Page 21 of 27 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


(4) Zhou, X.; Wang, A.; Yu, C.; Wu, S.; Shen, J. Facile Synthesis of Molecularly Imprinted Graphene Quantum Dots for the Determination of Dopamine with Affinity-Adjustable. ACS Appl. Mater. Interfaces 2015, 7, 11741-11747. (5) Wei, X.; Zhou, Z.; Dai, J.; Hao, T.; Li, H.; Xu, Y.; Gao, L.; Pan, J.; Li, C.; Yan, Y. Composites of Surface Imprinting Polymer Capped Mn-Doped ZnS Quantum Dots for Room-Temperature Phosphorescence Probing of 2,4,5-Trichlorophenol. J. Lumin. 2014, 155, 298-304. (6) Zhang, W.; He, X. W.; Chen, Y.; Li, W. Y.; Zhang, Y. K. Composite of CdTe Quantum Dots and Molecularly Imprinted Polymer as a Sensing Material for Cytochrome c. Biosens. Bioelectron. 2011, 26, 2553-2558. (7) Liu, J. X.; Hui, C.; Zhen, L.; Lin, J. M. Preparation of Surface Imprinting Polymer Capped Mn-Doped ZnS Quantum Dots and their Application for Chemiluminescence Detection of 4Nitrophenol in Tap Water. Anal. Chem. 2010, 82, 7380-7386. (8) Li, H.; Li, Y.; Cheng, J. Molecularly Imprinted Silica Nanospheres Embedded CdSe Quantum Dots for Highly Selective and Sensitive Optosensing of Pyrethroids. Chem. Mater. 2010, 22, 24512457. (9) Xu, S.; Lu, H. One-Pot Synthesis of Mesoporous Structured Ratiometric Fluorescence Molecularly Imprinted Sensor for Highly Sensitive Detection of Melamine from Milk Samples. Biosens. Bioelectron. 2015, 73, 160-166. (10) Liu, H.; Liu, D.; Fang, G.; Liu, F.; Liu, C.; Yang, Y.; Wang, S. A Novel Dual-Function Molecularly Imprinted Polymer on CdTe/ZnS Quantum Dots for Highly Selective and Sensitive Determination of Ractopamine. Anal. Chim. Acta 2013, 762, 76-82. (11) Zaman, M. B.; Bardelang, D.; Prakesch, M.; Leek, D. M.; Naubron, J. V.; Chan, G.; Wu, X.; Ripmeester, J. A.; Ratcliffe, C. I.; Yu, K. Size Reduction of CdSe/ZnS Quantum Dots by a Peptidic Amyloid Supergelator. ACS Appl. Mater. Interfaces 2012, 4, 1178-1181. (12) Zhou, J.; Li, H. Highly Fluorescent Fluoride-Responsive Hydrogels Embedded with CdTe Quantum Dots. ACS Appl. Mater. Interfaces 2012, 4, 721-724.


21


Page 22 of 27

(13) Fernando, K. A.; Sahu, S.; Liu, Y.; Lewis, W. K.; Guliants, E. A.; Jafariyan, A.; Wang, P.; Bunker, C. E.; Sun, Y. P. Carbon Quantum Dots and Applications in Photocatalytic Energy Conversion. ACS Appl. Mater. Interfaces 2015, 7, 8363-8376. (14) Amgar, D.; Aharon, S.; Etgar, L. Inorganic and Hybrid Organo-Metal Perovskite Nanostructures: Synthesis, Properties, and Applications. Adv. Funct. Mater. 2016, 26, 8576-8593. (15) Carey, G. H.; Abdelhady, A. L.; Ning, Z.; Thon, S. M.; Bakr, O. M.; Sargent, E. H. Colloidal Quantum Dot Solar Cells. Chem. Rev. 2015, 115, 12732-12763. (16) Fan, Z.; Razavi, H.; Do, J. W.; Moriwaki, A.; Ergen, O.; Chueh, Y. L.; Leu, P. W.; Ho, J. C.; Takahashi, T.; Reichertz, L. A. Three-Dimensional Nanopillar-Array Photovoltaics on Low-Cost and Flexible Substrates. Nature Mater. 2009, 8, 648-653. (17) Dong, N.; Li, Y.; Feng, Y.; Zhang, S.; Zhang, X.; Chang, C.; Fan, J.; Zhang, L.; Wang, J. Optical Limiting and Theoretical Modelling of Layered Transition Metal Dichalcogenide Nanosheets. Sci. Rep. 2015, 5, 14646. (18) Lee, M. M.; Teuscher, J.; Miyasaka, T.; Murakami, T. N.; Snaith, H. J. Efficient Hybrid Solar Cells Based on Meso-Superstructured Organometal Halide Perovskites. Science 2012, 338, 643647. (19) Jeon, N. J.; Noh, J. H.; Yang, W. S.; Kim, Y. C.; Ryu, S.; Seo, J.; Seok, S. I. Compositional Engineering of Perovskite Materials for High-Performance Solar Cells. Nature 2015, 517, 476480. (20) Dohner, E. R.; Jaffe, A.; Bradshaw, L. R.; Karunadasa, H. I. Intrinsic White-Light Emission from Layered Hybrid Perovskites. J. Am. Chem. Soc. 2014, 136, 13154-13157. (21) Li, G.; Tan, Z. K.; Di, D.; Lai, M. L.; Jiang, L.; Lim, H. W.; Friend, R. H.; Greenham, N. C. Efficient Light-Emitting Diodes Based on Nanocrystalline Perovskite in a Dielectric Polymer Matrix. Nano Lett. 2015, 15, 2640-2644. (22) Xing, G.; Mathews, N.; Lim, S. S.; Yantara, N.; Liu, X.; Sabba, D.; Grätzel, M.; Mhaisalkar, S.; Sum, T. C. Low-Temperature Solution-Processed Wavelength-Tunable Perovskites for Lasing. Nature Mater. 2014, 13, 476-480.


22

Page 23 of 27 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) Zhu, H.; Fu, Y.; Meng, F.; Wu, X.; Gong, Z.; Ding, Q.; Gustafsson, M. V.; Trinh, M. T.; Jin, S.; Zhu, X. Y. Lead Halide Perovskite Nanowire Lasers with Low Lasing Thresholds and High Quality Factors. Nature Mater. 2015, 14, 636-642. (24) Makarov, N. S.; Guo, S.; Isaienko, O.; Liu, W.; Robel, I.; Klimov, V. I. Spectral and Dynamical Properties of Single Excitons, Biexcitons, and Trions in Cesium–Lead–Halide Perovskite Quantum Dots. Nano Lett. 2016, 16, 2349-2362. (25) Chen, M.; Zou, Y.; Wu, L.; Pan, Q.; Yang, D.; Hu, H.; Tan, Y.; Zhong, Q.; Xu, Y.; Liu, H.; Sun, B.; Zhang, Q. Solvothermal Synthesis of High-Quality All-Inorganic Cesium Lead Halide Perovskite Nanocrystals: From Nanocube to Ultrathin Nanowire. Adv. Funct. Mater. 2017, 27, 1701121. (26) Yuan, S.; Chen, D.; Li, X.; Zhong, J.; Xu, X. In Situ Crystallization Synthesis of CsPbBr3 Perovskite Quantum Dot-Embedded Glasses with Improved Stability for Solid-State Lighting and Random Upconverted Lasing. ACS Appl. Mater. Interfaces 2018, 10, 18918-18926. (27) Wang, Y.; Li, X. M.; Song, J.; Xiao, L.; Zeng, H.; Sun, H. All-Inorganic Colloidal Perovskite Quantum Dots: A New Class of Lasing Materials with Favorable Characteristics. Adv. Mater. 2015, 47, 7101-7108. (28) Li, J.; Xu, L.; Wang, T.; Song, J.; Chen, J.; Xue, J.; Dong, Y.; Cai, B.; Shan, Q.; Han, B.; Zeng, H. 50-Fold EQE Improvement up to 6.27% of Solution-Processed All-Inorganic Perovskite CsPbBr3 QLEDs via Surface Ligand Density Control. Adv. Mater. 2017, 29, 1603885. (29) Yang, Z.; Wang, M.; Junjie, L.; Dou, J.; Qiu, H.; Shao, J. Spray-coated CsPbBr3 Quantum Dot Films for Perovskite Photodiodes. ACS Appl. Mater. Interfaces 2018, 10, 26387-26395. (30) Protesescu, L.; Yakunin, S.; Bodnarchuk, M. I.; Krieg, F.; Caputo, R.; Hendon, C. H.; Yang, R. X.; Walsh, A.; Kovalenko, M. V. Nanocrystals of Cesium Lead Halide Perovskites (CsPbX3, X = Cl, Br, and I): Novel Optoelectronic Materials Showing Bright Emission with Wide Color Gamut. Nano Lett. 2015, 15, 3692-3696.


23


Page 24 of 27

(31) Li, X.; Wu, Y.; Zhang, S.; Cai, B.; Gu, Y.; Song, J.; Zeng, H. CsPbX3 Quantum Dots for Lighting and Displays: Room-Temperature Synthesis, Photoluminescence Superiorities, Underlying Origins and White Light-Emitting Diodes. Adv. Funct. Mater. 2016, 26, 2435-2445. (32) Tong, Y.; Bladt, E.; Aygüler, M. F.; Manzi, A.; Milowska, K. Z.; Hintermayr, V. A.; Docampo, P.; Bals, S.; Urban, A. S.; Polavarapu, L. Highly Luminescent Cesium Lead Halide Perovskite Nanocrystals with Tunable Composition and Thickness by Ultrasonication. Angew. Chem. Int. Ed. 2016, 55, 13887-13892. (33) Zhang, H.; Wang, X.; Liao, Q.; Xu, Z.; Li, H.; Zheng, L.; Fu, H. Embedding Perovskite Nanocrystals into a Polymer Matrix for Tunable Luminescence Probes in Cell Imaging. Adv. Funct. Mater. 2017, 27, 1604382. (34) Li, Z.; Kong, L.; Huang, S.; Li, L. Highly Luminescent and Ultrastable CsPbBr3 Perovskite Quantum Dots Incorporated into a Silica/Alumina Monolith. Angew.Chem. Int. Ed. 2017, 56, 8134-8138. (35) Sun, C.; Zhang, Y.; Ruan, C.; Yin, C.; Wang, X.; Wang, Y.; Yu, W. W. Efficient and Stable White LEDs with Silica-Coated Inorganic Perovskite Quantum Dots. Adv. Mater. 2016, 28, 1008810094. (36) Chullasat, K.; Nurerk, P.; Kanatharana, P.; Davis, F.; Bunkoed, O. A Facile Optosensing Protocol Based on Molecularly Imprinted Polymer Coated on CdTe Quantum Dots for Highly Sensitive and Selective Amoxicillin Detection. Sens. Actuators B. 2018, 254, 255-263. (37) Swarnkar, A.; Chulliyil, R.; Ravi, V. K.; Irfanullah, M.; Chowdhury, A.; Nag, A. Colloidal CsPbBr3 Perovskite Nanocrystals: Luminescence beyond Traditional Quantum Dots. Angew. Chem. Int. Ed. 2015, 54, 15424-15428. (38) Wu, K.; Liang, G.; Shang, Q.; Ren, Y.; Kong, D.; Lian, T. Ultrafast Interfacial Electron and Hole Transfer from CsPbBr3 Perovskite Quantum Dots. J. Am. Chem. Soc. 2015, 137, 1279212795. (39) Dirin, D. N.; Protesescu, L.; Trummer, D.; Kochetygov, I. V.; Yakunin, S.; Krumeich, F.; Stadie, N. P.; Kovalenko, M. V. Harnessing Defect-Tolerance at the Nanoscale: Highly


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Luminescent Lead Halide Perovskite Nanocrystals in Mesoporous Silica Matrixes. Nano Lett. 2016, 16, 5866-5874. (40) Song, Y.; Cao, X.; Guo, Y.; Chen, P.; Zhao, Q.; Shen, G. Fabrication of Mesoporous CdTe/ZnO@SiO2 Core/Shell Nanostructures with Tunable Dual Emission and Ultrasensitive Fluorescence Response to Metal Ions. Chem. Mater. 2009, 21, 68-77. (41) Ren, X.; Chen, L. Quantum Dots Coated with Molecularly Imprinted Polymer as Fluorescence Probe for Detection of Cyphenothrin. Biosens. Bioelectron. 2015, 64, 182-188. (42) Kim, Y.; Yassitepe, E.; Voznyy, O.; Comin, R.; Walters, G.; Gong, X.; Kanjanaboos, P.; Nogueira, A. F.; Sargent, E. H. Efficient Luminescence from Perovskite Quantum Dot Solids. ACS Appl. Mater. Interfaces 2015, 7, 25007-25013. (43) Carrillo-Carrión, C.; Cárdenas, S.; Simonet, B. M.; Valcárcel, M. Quantum Dots Luminescence Enhancement Due to Illumination with UV/Vis Light. Chem. Commun. 2009, 35, 5214-5226.

BRIEFS Luminescent all-inorganic metal halide perovskite (CsPbBr3) quantum dots as sensing elements combined with molecularly imprinted polymers are used for the detection of omethoate.

SYNOPSIS


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Luminescent all-inorganic metal halide perovskite (CsPbBr3) quantum dots as sensing element combined with the molecularly imprinted polymers material are used for the detection of omethoate. 457x610mm (300 x 300 DPI)


Novel Fluorescence Sensor Based on All-Inorganic Perovskite

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