Research Article pubs.acs.org/journal/ascecg
Label-Free Colorimetric Nanosensor for the Selective On-Site Detection of Aqueous Al3+ Priyanka Joshi,† Ritu Painuli,† and Dinesh Kumar*,‡ †
Department of Chemistry, Banasthali University, Rajasthan-304022, India School of Chemical Sciences, Central University of Gujarat, Gandhinagar-382030, India
‡
S Supporting Information *
ABSTRACT: Aluminum is a hazardous element, found abundantly in the environment. Although many methods have been reported for the efficient detection of aluminum, an easy and accessible sensor for fast detection of aqueous aluminum has not been devised to date. In this approach, we have synthesized indole-2-carboxylic acid capped silver nanoparticles (I2CA-AgNPs) using a one-pot method and used them as label-free nanosensors for the detection of Al3+ in the presence of interfering metal ions. I2CA-AgNPs were synthesized by two methods at different temperatures. AgNPs synthesized by the heating method were further used as detection probes as they showed a strong and narrow surface plasmon resonance (SPR) peak in the visible region. The sensitivity of the detection probe has been optimized by variations in size and distribution of nanoparticles. Synthesized AgNPs were characterized by UV−vis spectroscopy, high-resolution transmission electron microscopy (HRTEM), Fourier transform infrared (FT-IR), zeta potential, and dynamic light scattering (DLS) analysis. Based on these results, I2CA-AgNPs could be used as colorimetric sensors to selectively detect the presence of Al3+. Further, results are confirmed by theoretical calculations of binding energy by density functional theory (DFT). Moreover, the nanosensor can also be applied to trace aluminum contamination in different types of water samples. The lower detection limit of the proposed method is 0.01 ppm (S/N = 3) which falls in the permissible limit set by the United States Environmental Protection Agency (USEPA), i.e. 50 ppm. KEYWORDS: Silver nanoparticles (AgNPs), Indole-2-carboxylic acid (I2CA), Density functional theory, colorimetric detection, Aluminum ions (Al3+), Aluminum nanoparticles (AlNPs)
■
plasma-atomic emission spectrometry (ICP-AES),12 inductively coupled plasma-mass spectroscopy (ICP-MS),13 graphite furnace atomic absorption spectrometry (GF-AAS),14 and electrochemical methods.15 Although these methods are sensitive, they have some limitations as they are expensive, often require tedious sample treatment, and show high background signals.16 Therefore, the development of a rapid, effective, sensitive, selective, label-free detection method for Al3+ sensing is a critical requirement. Nanoparticles, on aggregation, display a visual color change which is useful for analysis without complex instruments.17 On the basis of aggregation mechanism, our research team reported many sensors by using nanoparticles and nanocomposites.18−20 Recently, we reported a selective and sensitive sensor for the detection of Cr3+ and Mn2+ ions, using green synthesized nanoparticles.21 There are many other reports on the colorimetric detection of metal ions.22,23 However, to date, very limited reports are available for the detection of Al3+ based on aggregation of AuNPs24−27 and none for the colorimetric detection of Al3+ by AgNPs in an aqueous medium, to the best
INTRODUCTION In recent years, the development of sensitive and selective detection methods for hazardous metal ions has interested researchers, given their importance in medicine, living systems, and the environment.1,2 However, many of them are toxic even at trace level concentrations.3,4 Among these toxic metal ions, aluminum is the third most prevalent metallic element in the earth’s crust. It is widely used in aliment additives, pharmaceuticals, and storage/cooking utensils.5 There is mounting evidence that unregulated amounts of aluminum in the human body cause damage to the nervous system, idiopathic Parkinson’s disease, impairment of memory, Alzheimer’s disease,6 and dialysis encephalopathy.7 The iron binding protein is the main carrier for Al3+ in plasma. Thus, Al3+ can easily enter the brain and reach the placenta and fetus. Aluminum concentrations in the brain should be maintained at 500 °C attributed may be due to the metallic oxides. The improved thermal stability of I2CA capped AgNPs could be due to the strong interaction of a stabilizing agent on the surface of the AgNPs. FT-IR Analysis. Synthesis of nanoparticles was further confirmed by the FT-IR spectra. In the spectra of pure I2CA (Figure 3a), a strong band at 3351 cm−1 and a small band at
Figure 3. FT-IR spectra of (a) I2CA, (b) I2CA-AgNPs, and (c) I2CAAgNPs with Al3+.
3428 cm−1 were observed, assigned to the −NH group involved in N−H···O hydrogen bonding and nonassociated −NH, respectively. A prominent and broad band was observed
Figure 4. Schematic representation of Al3+ induced aggregation of I2CA-AgNPs. 4556
DOI: 10.1021/acssuschemeng.6b02861 ACS Sustainable Chem. Eng. 2017, 5, 4552−4562
Research Article
ACS Sustainable Chemistry & Engineering s−1 scan rate. Figure S5a shows that I2CA exhibited one peak at −0.600 V in aqueous media with irreversible nature. During the initial forward scan, an increasingly reducing potential is applied due to which, the cathodic current increase at least over this time, as there are reducible analytes present in the system.47 At some point after the reduction potential of the analyte is reached, the cathodic current decreases as the concentration of reducible analyte start depleting. This negative potential of I2CA shows its reducing capacity.48 Correspondingly, Figure S5b depicts a voltammogram for Ag+ ion. Figure S6a-c shows the interaction of I2CA (0.0001 to 0.01 M) with Ag+ ions. Results indicate that Ag+ ions are not completely reduced to Ag0 at 0.0001 M of I2CA. However, upon increasing the concentration of I2CA, cathodic peak current increases linearly from 0.0001 to 0.01 M. This peak corresponds to the complete reduction of Ag+ ion to Ag0.17 Selectivity Test for Al3+ by I2CA-AgNPs. It is a well-known fact that the oxygen and nitrogen containing ligands have a high affinity for electropositive metal ions.49 Based on this fact, we have synthesized I2CA-AgNPs which show high selectivity for the Al3+ ions. Figure 5a displays the UV−vis extinction spectra before and after adding various metal ions to the I2CA-AgNPs solution. In this series of studies, I2CA-AgNPs led to a significant change in SPR peak, which is attributed due to the formation of a colored complex between ligand and Al3+ while other metal ions led to an only minor change in the SPR peak. The selectivity of probe toward Al3+ was further quantified by plotting the absorption intensity ratio (A550/A405) of the I2CAAgNPs solution against different metal ions (10−100 ppm) as shown in Figure S7. The Al3+ induced values of A550/A405 are significantly greater than the values observed for other metal ions which show that the value of A550/A405 can be used to display the distinctive interaction between the Al3+ and I2CAAgNPs. Additionally, the marked bathochromic shift and augmentation in the values of A550/A405 were confirmed by the naked-eye with the color change in the solution of detection probe from brown to reddish-brown immediately after the addition of Al3+ (Figure 5b). After 15 min, it led to the precipitation of I2CA-AgNPs. However, there is no change in the color of the nanoparticles solution with the addition of other environmentally relevant metal ions. It is apparent from Figure 5c that there were significant optical changes for Al3+ ions, irrespective of the presence of other cations. Further, the selectivity toward Al3+ ion was confirmed in synthetic water. We prepared two different types of synthetic water samples (a and b) containing all above-mentioned metal ions. Sample b had additional Al3+ ions while sample a did not have additional Al3+ ions. We interacted both the samples with I2CA-AgNPs and got encouraging results. I2CA-AgNPs sensed Al3+ in sample b even in the presence of other environmentally relevant metal ions and gave negative results with the sample as shown in Inset Figure 5c. The results confirm that the interaction between Al3+ ions and AgNPs are unaffected by the presence of other metal ions. However, the sensor was found to give false positive results when the concentration of other metal ions is higher than 3 ppm in synthetic water samples. Theoretical Calculation. Herein, we discuss the binding energy of Al3+ ion and Ga3+ ion for I2CA-AgNPs. This is the most important parameter in the evaluation of the interaction between metal ions and sensor. For the purpose, the structure of sensor and sensor-metal complex was optimized by PBE0/ LANL2DZ/6-311G**. The optimized structures are displayed
Figure 5. (a) UV−vis spectra of the I2CA-AgNPs upon addition of different metal ions, (b) visual color change of the I2CA-AgNPs upon addition of various metallic ions, and (c) photographic image of the detection systems incubated with mixture of Al3+ and other ions. (inset) Response of I2CA-AgNPs in synthetic water samples.
in Figure S8. The calculated value of binding energy for Al3+ ion is −135.83 kcal/mol which is much higher than the binding energy calculated for Ga3+ (−65.95 kcal/mol). The result shows that the binding strength for Al3+ is higher than Ga3+, which agrees well with experimental results. Sensitivity of the I2CA-AgNPs to Al3+. The performance of the developed Al3+ sensor depends upon the pH of the solution because the pH of the solution not only influences the synthesis of nanoparticles but also affects the interaction between I2CAAgNPs and Al3+ ions. As mentioned above, the synthesized I2CA-AgNPs have maximum stability at pH 8, but there is not much change observed in the pH range from 7 to 10. We found that the value of A550/A405 was maximum at pH 8.0 and then decreased as shown in Figure 6a. This phenomenon may be due to the formation of aluminum hydroxide precipitates in high alkaline solution.26 Thus, the whole experiment was performed at pH 8.0. Quantitative analysis was conducted by adding different concentrations of Al3+ into I2CA-AgNPs solution and the changes in intensity, width, and position of SPR peak were 4557
DOI: 10.1021/acssuschemeng.6b02861 ACS Sustainable Chem. Eng. 2017, 5, 4552−4562
Research Article
ACS Sustainable Chemistry & Engineering
Figure 6. (a) Effect of pH on sensing, (b) UV−vis spectra of I2CA-AgNPs at Al3+ ion concentration of 0.001−10 ppm, (c) color change of I2CAAgNPs solution upon addition of different concentrations of Al3+ ions under the optimized conditions, (d) dose−response curve for the detection of Al3+ ion (A550/A405 ratios), (e) linear calibration plot for the concentration of Al3+ ion in the range of 0.5−10 ppm. The absorbance ratio was measured in triplicate for each concentration of Al3+ ion, and error bars present standard deviation. HRTEM images of I2CA-AgNPs (f) before and (g) after interaction with Al3+ ion.
(Figure 6d). The plot of Al3+ with concentration ranging from 0.5 to 10 ppm shows a linear correlation and value of linear regression coefficients (R2) was 0.9924 (Figure 6e). The color of the solution remains like control at an Al3+ concentration of 0.001 ppm. Therefore, our sensor’s limit of detection by the naked eye is 0.01 ppm making it suitable for the quantitative determination of Al3+ ions at the parts per million level in aqueous solutions. The result was also confirmed by UV−vis spectra which did not show any change in the characteristic peak of nanoparticles beyond 0.01 ppm of Al3+.50 To check the reproducibility with respect to sensing ability of synthesized I2CA-AgNPs, eight replicate experiments were performed for 0 ppm (blank) and 0.01 ppm of Al3+ (Figure S9). The value of
monitored by UV−vis spectroscopy. It is apparent from Figure 6b that the intensity of the SPR peak at 405 nm decreases as the function of Al3+ concentration with the generation of a new peak at 550 nm. So, these two wavelengths were chosen to show the amount of monodispersed and aggregated particles, respectively. In the presence of Al3+ ion color of I2CA-AgNPs changes to reddish brown, which undergoes precipitation at higher concentration (Figure 6c). The colorimetric changes in I2CA-AgNPs solution could be due to the interaction of functional groups present on the surface of NPs with Al3+ by metal−ligand interaction; thereby the Al3+ ions induced the aggregation of AgNPs. The plot of A550/A405 against the various concentrations of Al3+ shows the dose response of the assay 4558
DOI: 10.1021/acssuschemeng.6b02861 ACS Sustainable Chem. Eng. 2017, 5, 4552−4562
Research Article
ACS Sustainable Chemistry & Engineering A550/A405 nm for 0.01 ppm Al3+ is significantly similar for all the replicates which confirm their sensing reproducibility.51 The higher value of A550/A405 was obtained for 0.01 ppm of Al3+ ions than that for blank, but there is no difference in the A550/ A405 value between 0.009 ppm and blank which further confirms the LOD is 0.01 ppm (S/N = 3), and the relative standard deviation is 1.3%.52 The interaction of I2CA-AgNPs with Al3+ was also confirmed by nuclear magnetic resonance (NMR) spectroscopy. Figure S10a and b shows the NMR spectra of pure I2CA and I2CA-AgNPs after interaction with Al3+. Results indicate that not much change was observed in the basic unit, only the functional groups take part in interaction with Al3+ ions. HRTEM analyses were carried out in the presence and absence of Al3+ ions, under identical conditions. Figure 6f shows that the synthesized I2CA-AgNPs are apparently monodispersed, and 5 to 20 nm in average diameter which undergoes aggregation on the addition of Al3+ (Figure 6g). Further, DLS measurement was carried out to show the aggregation of nanoparticles upon interaction with Al3+. Figure S11a shows the particles had an average diameter of 19 nm in the absence of Al3+ which increases progressively up to 286 nm on increasing the concentration of Al3+. Further the decrease in zeta potential from −25 to 21.9 mV confirmed aggregation of I2CA-AgNPs in the presence of Al3+ (Figure S11b).17 Based on the observed UV−vis spectral changes, HRTEM images, FT-IR spectra, zeta potential, and DLS measurements, we propose a possible mechanism for the interaction of AgNPs with Al3+ in an aqueous medium as shown in Figure 4. Upon addition of Al3+ into the AgNPs solution, the intensity of the SPR band gradually decreases with the generation of a new peak for Al3+ ions. Al3+ is a hard acid, and it tends to coordinate preferably with a hard base such as N and O atom.53,54 Thus, the Al3+ coordinate with the functional groups (NH−CO) present on the NP surface through metal−ligand interactions. As a result, these NPs come closer to each other which leads to the cross-linking aggregation of I2CA-AgNPs, causing a change in the color of the solution from brown to reddish brown. The coordination of Al3+ ion with N and O atoms was confirmed by the disappearance of the peaks at 3416 and 1571 cm−1. The shifting of the peak from 1567 to 1538 cm−1 shows the decrease in double bond character in CO upon its coordination with Al3+ ion, and the appearance of a new peak at 973 cm−1 confirms coordination of Al3+ ion (Figure 3c). The high specificity of the I2CA-AgNPs for Al3+ can be explained based on multiple numbers of N and O atoms present in the system.55,56 Energy Dispersive X-ray Analysis. EDX analysis was performed to show the synthesis of I2CA-AgNPs and their interaction with Al3+ ions. Figure S12a shows the characteristic peaks at 3 keV corresponding to Ag characteristic L line.57 The other peaks with high intensity are due to the C, N, and O which constitute the basic unit of reducing and stabilizing agent I2CA. In Figure S12b the presence of peaks which correspond to the Al3+ ions confirm the interaction of I2CA-AgNPs with Al3+ ions. Interaction of I2CA with AlNPs. The formation of AlNPs was confirmed by P-XRD (Figure S13a). Results were in good agreement with the results reported by Murlidharan et al.58 which revealed the face-centered cubic (FCC) arrangement of aluminum. To support the mechanism of Al3+ sensing, we attempted interaction between AlNPs with I2CA but the stumbling block was that the formed AlNPs were not dispersed
in an aqueous medium, which was the base for all our previous reactions. To solve this problem, we checked their dispersion in various solvents. They were found to be soluble in acetic acid. I2CA is also soluble in acetic acid. Therefore, acetic acid was chosen as the medium for their interaction. UV−vis spectra of AlNPs in acetic acid did not show any peak except a small shoulder around 299 nm. No additional peak or any change in UV−vis spectra of I2CA was observed on addition of AlNPs confirming that there is no interaction between AlNPs and I2CA (Figure S13b). The FESEM image of AlNPs in acetic acid showed that particles get aggregated and move toward the formation of oxides (Figure S13c). Particle size distribution was derived from a histogram measured using multiple FESEM micrographs (Figure S13d). Effects of Size Variations and Distribution of I2CA-AgNPs on Sensing. To know the effect of size on sensing response, we considered Ag (8 nm) and Ag (32 nm) particles. With the increasing size of nanoparticles, an increase in sensitivity from 0.01 to 0.005 ppm was observed. The sensitivity of the sensor is mainly governed by shape, orientation, interparticle distance, size and distribution of aggregates (number of particles). As the size of nanoparticles increase, distribution of aggregates increases, which results in a decrease of the interparticle distance between particles. This, in turn, enhances the sensitivity by plasmon coupling of nanoparticles.59 Another reason for increased sensitivity could be due to increase radiative damping or retardation.60 Figure 7a shows the UV−vis
Figure 7. (a) UV−vis spectra and (b) optical image of I2CA-AgNPs (32 nm) in the presence of Al3+. (c) HRTEM image showing the aggregation of particles in the presence of Al3+.
spectra of I2CA-AgNPs (32 nm) with Al 3+ . As the concentration of Al3+ increases, a continuous decrease in intensity was observed with the generation of a new shoulder at 682 nm. Correspondingly, the color of nanoparticles solution changes from greenish black to orange-brown (Figure 7b). The aggregation of nanoparticles was confirmed by HRTEM analysis (Figure 7c). Although the nanoparticles with large size are more sensitive, their stability is lower and this limits their application. 4559
DOI: 10.1021/acssuschemeng.6b02861 ACS Sustainable Chem. Eng. 2017, 5, 4552−4562
Research Article
ACS Sustainable Chemistry & Engineering Application of the Sensor. To validate the practical application of the proposed label-free colorimetric method, its response on tap and pond water samples was tested. However, we could not detect Al3+ in the samples as the concentration of Al3+ in tap and pond water samples were very low which may be less than the sensitivity limit of our proposed method. Tap and pond water samples were spiked with various concentrations of Al3+ in the range of 0.001 to 10 ppm and tested in the system. The visual response of sensor linearly increased with increasing Al3+ concentration as shown in Figure 8. Sensor
Table 1. Recovery Results from Spiked Real Water Samples sample tap water pond water
■
added amount of 3+ Al (ppm)
found amount (ppm) (mean ± E, and n = 3)
recovery (%) (mean ± E, and n = 3)
AAS
0.5 2.0 0.5 2.0
0.49 ± 0.01 2.1 ± 0.02 0.51 ± 0.019 1.98 ± 0.01
98 ± 2 105 ± 2.5 102 ± 3.8 99 ± 0.50
0.53 0.19 0.50 0.19
CONCLUSIONS The outcomes of this research indicate the development of a novel and selective sensor for the label-free colorimetric sensing of Al3+. Various conditions such as pH, time, temperature, and concentration of I2CA were studied for the synthesis of nanoparticles. AgNPs synthesized by the heating method is more suitable for the efficient sensing of the metal ion as they show a strong narrow band and require a shorter time for the reduction of Ag+ ions. AgNPs show the good colorimetric response for Al3+ with excellent selectivity as other environmentally relevant metal ions do not show interference with Al3+. The reaction conditions for the experiment were set at 0.001 M AgNO3, 0.01 M I2CA, and pH 8. A 100 μL portion of the metal ion solution was added into 400 μL of I2CA-AgNPs which was suitable for the detection of Al3+ with instant response in millipore, tap, and pond water samples. The sensor shows high selectivity for Al3+, but at the concentration of 100 ppm of some metal ions (Ni2+, Co2+, and Cr3+) starts to interfere. Theoretical calculation by DFT confirms binding of Al3+ ion with I2CA-AgNPs. When the simultaneous presence of other environmentally relevant metal ions is higher than 3 ppm, sensor gives false positive results. Effect of size on the sensing of Al3+ was also investigated which shows that the large particles show improved sensitivity. It has several advantages over other existing techniques for Al3+ ion sensingit does not require any complicated instrumentation or modification which simplifies the operation and reduces associated costs. The sensor allows the detection of Al3+ ion in concentrations as low as 0.01 ppm by the naked eyes and spectroscopically.
Figure 8. Colorimetric response of I2CA-AgNPs as a function of Al3+ ion concentration in (a) tap water and (b) pond water samples.
■
responses in distilled water, tap water, and pond water are very similar, suggesting that the colorimetric assay can detect Al3+ without being affected by the interfering tap and pond water environment. To further show the validity of the method, a recovery test was also performed for the determination of Al3+ on tap and pond water samples. When two different concentrations of Al3+ were spiked and then analyzed using the standard addition method, recovery of Al3+ in the range from 96% to 107.5% was obtained. The observed concentration in tap and pond water samples by our proposed method was very close to the concentration determined by the AAS (Table 1). The sensitivity of this colorimetric sensor was compared to reported methods using nanoparticles as sensors.23−25,61−63 The limit of detection of our proposed method is lower or comparable to the other reported methods for Al3+ ion (Table S2). Easy synthesis, short response time, working at physiological pH, and application to the real water samples makes the present method more advantageous over other reported methods.
The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acssuschemeng.6b02861. UV−vis spectra of I2CA-AgNPs illustrating reproducibility of with respect to size, HRTEM images at different magnifications, and histograms representing the synthetic reproducibility with respect to size. Size distribution of I2CA-AgNPs at (a) 405 and (b) 427 nm. Calculation of fwhm of I2CA-AgNPs synthesized at (a) 0.01 and (b) 0.1 M concentration of I2CA. Thermogram of (a) I2CA, (b) I2CA-AgNPs. Cyclic voltammogram of (a) I2CA and (b) AgNO3. Cyclic voltammogram of I2CA-AgNPs synthesized with (a) 10, (b) 15, and 20 mL of I2CA, selectivity of I2CA-AgNPs in the presence of different concentrations (10−100 ppm) of various heavy metal ions, the graphical structure of (a) I2CA-AgNPs, and its complexes with (b) Al3+ and (b) Ga3+. Sensing reproducibility of I2CA-AgNPs for Al3+. 1H NMR spectra of (a) I2CA and (b) I2CA-AgNPs after interaction with Al3+ ions. Size distribution of I2CAAgNPs before and after addition of Al3+ ion. Zeta
ASSOCIATED CONTENT
S Supporting Information *
4560
DOI: 10.1021/acssuschemeng.6b02861 ACS Sustainable Chem. Eng. 2017, 5, 4552−4562
Research Article
ACS Sustainable Chemistry & Engineering
■
(9) Srinivasan, P. T.; Viraraghavan, T.; Subramanian, K. S. Aluminium in drinking water: An overview. Water SA 1999, 25, 47− 56. (10) WHO. Guidelines for drinking water quality; Geneva, 2008; p 301. (11) Şatıroğlu, N.; Tokgöz, I.̇ Cloud point extraction of aluminum (III) in water samples and determination by electrothermal atomic absorption spectrometry, flame atomic absorption spectrometry and UV-visible spectrophotometry. Int. J. Environ. Anal. Chem. 2010, 90, 560−572. (12) Hirata, S.; Umezaki, Y.; Ikeda, M. Determination of chromium(III), titanium, vanadium, iron(III), and aluminum by inductively coupled plasma atomic emission spectrometry with an on-line Preconcentrating ion exchange column. Anal. Chem. 1986, 58, 2602−2606. (13) Tao, G.; Yamada, R.; Fujikawa, Y.; Kojima, R.; Zheng, J.; Fisher, D. A.; Koerner, R. M.; Kudo, A. Determination of major metals in arctic snow by inductively coupled plasma mass spectrometry with cold plasma and micro concentric nebulization techniques. Int. J. Environ. Anal. Chem. 2000, 76, 135−144. (14) Mitrovic, B.; Milacic, R. Speciation of aluminum in forest soil extracts by size exclusion chromatography with UV and ICP-AES detection and cation exchange fast protein liquid chromatography with ETAAS detection. Sci. Total Environ. 2000, 258, 183−194. (15) Kefala, G.; Economou, A.; Sofoniou, M. Determination of trace aluminium by adsorptive stripping voltammetry on a preplated bismuth-film electrode in the presence of Cupferron. Talanta 2006, 68, 1013−1019. (16) Mehta, N. K.; Kailasa, S. K. Malonamide dithiocarbamate functionalized gold nanoparticles for colorimetric sensing of Cu2+ and Hg2+ ions. RSC Adv. 2015, 5, 4245−4255. (17) Annadhasan, M.; Kasthuri, J.; Rajendiran, N. Green synthesis of gold nanoparticles under sunlight irradiation and their colorimetric detection of Ni2+ and Co2+ ions. RSC Adv. 2015, 5, 11458−11468. (18) Thatai, S.; Khurana, P.; Prasad, S.; Soni, S. K.; Kumar, D. Trace colorimetric detection of Pb2+ using plasmonic gold nanoparticles and silica−gold nanocomposites. Microchem. J. 2016, 124, 104−110. (19) Thatai, S.; Khurana, P.; Prasad, S.; Kumar, D. Plasmonic detection of Cd2+ ions using surface-enhanced Raman scattering active core−shell nanocomposite. Talanta 2015, 134, 568−575. (20) Thatai, S.; Khurana, P.; Prasad, S.; Kumar, D. A new way in nanosensors: Gold nanorods for sensing of Fe(III) ions in aqueous media. Microchem. J. 2014, 113, 77−82. (21) Joshi, P.; Nair, M.; Kumar, D. pH-controlled sensitive and selective detection of Cr(III) and Mn(II) by using clove (S. aromaticum) reduced and stabilized silver nanospheres. Anal. Methods 2016, 8, 1359−1366. (22) Manjumeena, R.; Duraibabu, D.; Rajamuthuramalingam, T.; Venkatesan, R.; Kalaichelvan, P. T. Highly responsive glutathione functionalized green AuNPs probe for precise colorimetric detection of Cd2+ contamination in the environment. RSC Adv. 2015, 5, 69124− 69133. (23) Dong, C.; Wu, G.; Wang, Z.; Ren, W.; Zhang, Y.; Shen, Z.; Li, T.; Wu, A. Selective colorimetric detection of Cr(III) and Cr(VI) using gallic acid capped gold nanoparticles. Dalton Trans. 2016, 45, 8347−8354. (24) Li, X.; Wang, J.; Sun, L.; Wang, Z. Gold nanoparticle-based colorimetric assay for selective detection of aluminum cation on living cellular surfaces. Chem. Commun. 2010, 46, 988−990. (25) Chen, Y. C.; Lee, I. L.; Sung, Y. M.; Wu, S. P. Colorimetric detection of Al3+ ions using triazole-ether functionalized gold nanoparticles. Talanta 2013, 117, 70−74. (26) Xue, D.; Wang, H.; Zhang, Y. Specific and sensitive colorimetric detection of Al3+ using 5-mercaptomethyltetrazole capped gold nanoparticles in aqueous solution. Talanta 2014, 119, 306−311. (27) Zhang, M.; Liu, Y.-Q.; Ye, B.-C. Mononucleotide-modified metal nanoparticles: An efficient colorimetric probe for the selective and sensitive detection of Al(III) ion on living cellular surfaces. Chem. Eur. J. 2012, 18, 2507−2513.
potential distribution of I2CA-AgNPs before and after interaction with Al3+ ions. EDX spectra of (a) I2CAAgNPs and (b) I2CA-AgNPs after interaction with Al3+ ions. P-XRD pattern of synthesized AlNPs. UV−vis spectra of I2CA in the presence of AlNPs. FESEM images of AlNPs in acetic acid. Histogram of AlNPs. Characterization of I2CA-AgNPs with different sizes. Comparison of reported colorimetric methods with present work in terms of reducing and stabilizing agent, pH, and limit of detection (PDF)
AUTHOR INFORMATION
Corresponding Author
*E-mail:
[email protected] ORCID
Dinesh Kumar: 0000-0001-5488-951X Notes
The authors declare no competing financial interest.
■
ACKNOWLEDGMENTS
■
REFERENCES
We gratefully acknowledge support from the Ministry of Human Resource Development, Department of Higher Education, Government of India, under the scheme of Establishment of Centre of Excellence for Training and Research in Frontier Areas of Science and Technology (FAST), vide letter No, F. No. 5-5/201 4-TS. Vll. The authors also thank AIIMS, New Delhi, and University of Rajasthan, Jaipur, for the providing HRTEM facility. Profound gratitude is extended to Dr. Ruby Srivastava, DST scientist, CSIR, IICT Hyderabad, and Dr. G. Narhari Sastry, H.O.D., Centre for molecular modeling, CSIR, IICT, for computational work.
(1) Ma, Y.-R.; Niu, H.-Y.; Zhang, X.-L.; Cai, Y.-Q. Colorimetric detection of copper ions in tap water during the synthesis of silver/ dopamine nanoparticles. Chem. Commun. 2011, 47, 12643−12645. (2) Ha, W.; Yu, J.; Wang, R.; Chen, J.; Shi, Y.-P. Green” colorimetric assay for the selective detection of trivalent chromium based on Xanthoceras sorbifolia tannin attached to gold nanoparticles. Anal. Methods 2014, 6, 5720−5726. (3) Chen, Y.; Yao, L.; Deng, Y.; Pan, D.; Ogabiela, E.; Cao, J.; Adeloju, S. B.; Chen, W. Rapid and ultrasensitive colorimetric detection of mercury(II) by chemically initiated aggregation of gold nanoparticles. Microchim. Acta 2015, 182, 2147−2154. (4) Leng, Y.; Li, Y.; Gong, A.; Shen, Z.; Chen, L.; Wu, A. Colorimetric response of dithizone product and hexadecyl trimethyl ammonium bromide modified gold nanoparticle dispersion to 10 types of heavy metal ions: Understanding the involved molecules from experiment to simulation. Langmuir 2013, 29, 7591−7599. (5) Kim, K. B.; You, D. M.; Jeon, J. H.; Yeon, Y. H.; Kim, J. H.; Kim, K. A fluorescent and colorimetric chemosensor for selective detection of aluminum in aqueous solution. Tetrahedron Lett. 2014, 55, 1347− 1352. (6) Mergu, N.; Singh, A. K.; Gupta, V. K. Highly sensitive and selective colorimetric and off-on fluorescent reversible chemosensors for Al3+ based on the rhodamine fluorophore. Sensors 2015, 15, 9097− 9111. (7) Nathan, E.; Pedersen, S. E. Dialysis encephalopathy in a nondialyseduraemic boy treated with aluminium hydroxide orally. Acta Paediatr. 1980, 69, 793−796. (8) Andrasi, E.; Pali, N.; Molnar, Z.; Kosel, S. Brain Al, Mg and P contents of control and Alzheimer-diseased patients. J. Alzheimer's Dis. 2005, 7, 273−284. 4561
DOI: 10.1021/acssuschemeng.6b02861 ACS Sustainable Chem. Eng. 2017, 5, 4552−4562
Research Article
ACS Sustainable Chemistry & Engineering (28) Chen, S.; Fang, Y.-M.; Xiao, Q.; Li, J.; Li, S.-B.; Chen, H.-J.; Sun, J.-J.; Yang, H.-H. Rapid visual detection of aluminum ion using citratecapped gold nanoparticles. Analyst 2012, 137, 2021−2023. (29) Noh, K.-C.; Nam, Y.-S.; Lee, H.-J.; Lee, K.-B. A colorimetric probe to determine Pb2+ using functionalized silver nanoparticles. Analyst 2015, 140, 8209−8216. (30) Nanda Kumar, D. N.; Rajeshwari, A.; Alex, S. A.; Chandrasekaran, N.; Mukherjee, A. Acetylcholinesterase inhibitionbased colorimetric determination of Hg2+ using unmodified silver nanoparticles. New J. Chem. 2015, 39, 1172−1178. (31) Keawwangchai, T.; Morakot, N.; Wanno, B. Fluorescent sensors based on BODIPY derivatives for aluminium ion recognition: an experimental and theoretical study. J. Mol. Model. 2013, 19, 1435− 1444. (32) Perdew, J. P.; Burke, K.; Ernzerhof, M. Generalized gradient approximation made simple. Phys. Rev. Lett. 1996, 77, 3865−3868. (33) Perdew, J. P.; Burke, K.; Ernzerhof, M. Generalized gradient approximation made simple. Phys. Rev. Lett. 1997, 78, 1396. (34) Hay, P. J. Theoretical studies of the ground and excited electronic states in cyclometalated phenylpyridine Ir(III) complexes using density functional theory. J. Phys. Chem. A 2002, 106, 1634− 1641. (35) Andonovski, B. S. UV Study of the Protonation of indole-2carboxylic acid, 3-methylindole, 3-acetylindole and D-tryptophan in perchloric acid solutions. Croat. Chem. Acta. 1999, 72, 711−726. (36) Ihsan, M.; Niaz, A.; Rahim, A.; Zaman, M. I.; Arain, M. B.; Sirajuddin; Sharif, T.; Najeeb, M. Biologically synthesized silver nanoparticles-based colorimetric sensor for the selective detection of Zn2+. RSC Adv. 2015, 5, 91158−91165. (37) Agnihotri, S.; Mukherji, S.; Mukherji, S. Size-controlled silver nanoparticles synthesized over the range 5−100 nm using the same protocol and their antibacterial efficacy. RSC Adv. 2014, 4, 3974− 3983. (38) Han, X.; Wang, H.; Ou, X.; Zhang, X. Highly selective, reproducible and stable SERS sensors based on well-controlled silver nanoparticle-decorated silicon nanowire building blocks. J. Mater. Chem. 2012, 22, 14127−14132. (39) Pandey, S.; Mewada, A.; Thakur, M.; Shinde, S.; Shah, R.; Oza, G.; Sharon, M. Rapid biosynthesis of silver nanoparticles by exploiting the reducing potential of trapa bispinosa peel extract. J. Nanosci. 2013, 2013, 1−9. (40) Guo, Y.; Wang, Z.; Qu, W.; Shao, H.; Jiang, X. Colorimetric detection of mercury, lead and copper ions simultaneously using protein-functionalized gold nanoparticles. Biosens. Bioelectron. 2011, 26, 4064−4069. (41) Lewis, D. J.; Day, T. M.; MacPherson, J. V.; Pikramenou, Z. Luminescent nanobeads: attachment of surface reactive Eu(III) complexes to gold nanoparticles. Chem. Commun. 2006, 13, 1433− 1435. (42) Abthagir, P. S.; Saraswathi, R. Charge transport and thermal properties of polyindole, polycarbazole and their derivatives. Thermochim. Acta 2004, 424, 25−35. (43) Majeed Khan, M. A.; Kumar, S.; Ahamed, M.; Alrokayan, S. A.; AlSalhi, M. S. Structural and thermal studies of silver nanoparticles and electrical transport study of their thin films. Nanoscale Res. Lett. 2011, 6, 434−441. (44) Morzyk-Ociepa, B.; Michalska, D.; Pietraszko, A. Structures and vibrational spectra of indole carboxylic acids. Part I. Indole-2carboxylic acid. J. Mol. Struct. 2004, 688, 79−86. (45) Goyal, R. N.; Sangal, A. Oxidation chemistry of indole-2carboxylic acid mechanism and products formed in neutral aqueous solution. Electrochim. Acta 2005, 50, 2135−2143. (46) Martell, A. E.; Smith, R. M. Critical Stability Constants; Plenum Press: New York, 1982; pp 1−416. (47) Alam, M. N.; Chatterjee, A.; Das, S.; Batuta, S.; Mandal, D.; Begum, N. A. Burmese grape fruit juice can trigger the “logic gate”-like colorimetric sensing behavior of Ag nanoparticles towards toxic metal ions. RSC Adv. 2015, 5, 23419.
(48) Li, Y.; Chen, S.-M.; Ali, M. A.; AlHemaid, F. M. A. Biosynthesis and electrochemical characterization of silver nanoparticles from leaf extract of adenium obesum and its application to antibacterial effect. Int. J. Electrochem. Sci. 2013, 8, 2691−2701. (49) Azadbakht, R.; Khanabadi, J. A novel aluminum-sensitive fluorescent nano-chemosensor based on naphthalene macrocyclic derivative. Tetrahedron 2013, 69, 3206−3211. (50) Chen, N.; Zhang, Y.; Liu, H.; Ruan, H.; Dong, C.; Shen, Z.; Wu, A. A supersensitive probe for rapid colorimetric detection of nickel ion based on a sensing mechanism of anti-etching. ACS Sustainable Chem. Eng. 2016, 4, 6509−6516. (51) Lai, Y. J.; Tseng, W. L. Role of 5-thio-(2-nitrobenzoic acid)capped gold nanoparticles in the sensing of chromium(VI): remover and sensor. Analyst 2011, 136, 2712−2717. (52) Miller, J. N.; Miller, J. C. Statistics and chemometrics for analytical chemistry; Pearson/Prentice Hall, 2010, pp 1−268. (53) Ding, P.; Wang, J.; Cheng, J.; Zhao, Y.; Ye, Y. Three N-stabilized rhodamine-based fluorescent probes for Al3+ via Al3+-promoted hydrolysis of Schiff bases. New J. Chem. 2015, 39, 342−348. (54) Gupta, V. K.; Shoora, S. K.; Kumawat, L. K.; Jain, A. K. A highly selective colorimetric and turn-on fluorescent chemosensor based on 1-(2-pyridylazo)-2-naphthol for the detection of aluminium(III) ions. Sens. Actuators, B 2015, 209, 15−24. (55) Wang, J. Q.; Huang, L.; Gao, L.; Zhu, J.-H.; Wang, Y.; Fan, X.; Zou, Z. A small and robust Al(III)-chemosensor based on bis-Schiff base N,N′-(1,4-phenylene dimethylidyne) bis-1,4-benzene diamine. Inorg. Chem. Commun. 2008, 11, 203−206. (56) Ma, Y. H.; Yuan, R.; Chai, Y. Q.; Liu, X. L. A new aluminum(III)-selective potentiometric sensor based on N,N′propanediamidebis(2-salicylideneimine) as a neutral carrier. Mater. Sci. Eng., C 2010, 30, 209−213. (57) Agnihotri, S.; Mukherji, S.; Mukherji, S. Size-controlled silver nanoparticles synthesized over the range 5−100 nm using the same protocol and their antibacterial efficacy. RSC Adv. 2014, 4, 3974− 3983. (58) Ghanta, S. R.; Muralidharan, K. Chemical synthesis of aluminum nanoparticles. J. Nanopart. Res. 2013, 15, 1715−1724. (59) Guo, L.; Jackman, J. A.; Yang, H.-H.; Chen, P.; Cho, N.-J.; Kim, D.-H. Strategies for enhancing the sensitivity of plasmonic nanosensors. Nano Today 2015, 10, 213−239. (60) Jain, P. K.; El-Sayed, M. A. Surface plasmon resonance sensitivity of metal nanostructures: physical basis and universal scaling in metal nanoshells. J. Phys. Chem. C 2007, 111, 17451−17454. (61) Chen, W.; Jia, Y.; Feng, Y.; Zheng, W.; Wang, Z.; Jiang, X. Colorimetric detection of Al(III) in vermicelli samples based on ionic liquid group coated gold nanoparticles. RSC Adv. 2015, 5, 62260− 62264. (62) Mahajan, P. G.; Bhopate, D. P.; Kolekar, G. B.; Patil, S. R. A chalcone based novel fluorescent nanoprobe for selective detection of Al3+ ion in an aqueous medium. J. Lumin. Appl. 2015, 2, 1−13. (63) Sen, S.; Mukherjee, T.; Chattopadhyay, B.; Moirangthem, A.; Basu, A.; Marek, J.; Chattopadhyay, P. A water soluble Al3+ selective colorimetric and fluorescent turn-on chemosensor and its application in living cell imaging. Analyst 2012, 137, 3975.
4562
DOI: 10.1021/acssuschemeng.6b02861 ACS Sustainable Chem. Eng. 2017, 5, 4552−4562
