Colorimetric Dual Sensors of Metal Ions Based on 1,2,3-Triazole-4,5-Dicarboxylic Acid-Functionalized Gold Nanoparticles

Abstract

A simple, rapid, selective, and cost-effective colorimetric assay for Cr3+ and Eu3+ ion detection has been developed using functionalized gold nanoparticles. Gold nanoparticles (AuNPs) were prepared using HAuCl4, where sodium citrate is a reducing agent as well as a capping agent, and then functionalized with 1,2,3-triazole-4,5-dicarboxylic acid (TADA). Fourier transform infrared (FTIR) and Raman spectroscopies suggested that TADA was functionalized on the surface of AuNPs through the N atom of triazole. The TADA-functionalized gold nanoparticles (TADA@AuNPs) simultaneously detect Cr3+ and Eu3+ ions from aqueous solution and showed different responses to the two metal ions (Cr3+ and Eu3+) based on an aggregation-induced color change of AuNPs. They showed a color change from wine red to blue, which was easily detected by the naked eye, as well as by UV–visible and FTIR spectroscopies. The surface plasmon resonance absorbances of Cr3+ and Eu3+ are 633 and 671 nm, respectively, when Cr3+ and Eu3+ react with TADA@AuNPs and showed good linearity with Cr3+ and Eu3+ concentrations with detection limits 5.89 nM and 4.30 μM, respectively (S/N = 3). The TADA@AuNPs showed excellent selectivity toward Cr3+ and Eu3+ compared to those of the 16 different metal ions. We had also tested the selectivity of TADA@AuNPs toward Eu3+ compared to that of the other 10 lanthanide systems. Optimal detection was achieved toward Cr3+ and Eu3+ ions in the pH range 4–10. In addition, TADA@AuNPs were applied to detect Cr3+ and Eu3+ ions from lake water showing low interference.

Easy colorimetric detection of gadolinium ions based on gold nanoparticles: key role of phosphine-sulfonate ligands

“…S16 † for comparison). 3,51 The estimated value compares very favorably with the one estimated from ICP measurements 9.8 AE 0.5 mM with a higher accuracy. Hence, the application of the colorimetric test and the aggregation index method has proved to provide a good estimation of the concentrations of free gadolinium ions.…”

“…In that context the use of gold nanoparticles (AuNPs) as colorimetric sensing probes have piqued much interest 3 in addition to their application in biomedical imaging. 4 AuNPs are still today one of the largest studied inorganic colloids, due to their interesting photo-physical properties, easy preparation and functionalization.…”

Rapid and selective detection of aluminum ion using 1,2,3-triazole-4,5-dicarboxylic acid-functionalized gold nanoparticle-based colorimetric sensor

“… 51 When pH > 12, under strong alkaline conditions, the carboxyl groups of citrate and TADA may be deprotonated, and their coordination ability with AuNPs may decrease, making them unable to protect AuNPs, leading to aggregation of AuNPs covered with hydroxyl groups. 18 Thus, the effects of the pH range from 4 to 12 on the relative UV-vis absorption ratio ( A 650 nm / A 525 nm ) was further studied in the presence of Al 3+ , and the results are shown in Fig. 6b .…”

“…The TADA–AuNPs were prepared using a previously reported method, with some improvement. 18 To synthesize citrate-terminated AuNPs (citrate–AuNPs), 100 mL of 0.25 mM chloroauric acid (HAuCl 4 ) aqueous solution were boiled, followed by the rapid addition of 4 mL of 40 mM sodium citrate (Na 3 Ct) solution. The Na 3 Ct/HAuCl 4 molar ratio was 6.4 : 1.…”

“…Taking advantages of unique surface plasmon resonance (SPR) absorption, easy surface functionalization and variable solution colors, AuNPs have been used for colorimetric sensing in food security, environmental monitoring, and health care. [8][9][10][11] Potential applications include the determination of metal ions, [12][13][14][15][16][17][18] pesticide residues, 19,20 bisphenol A (BPA), 21,22 phosphate, 23 azodicarbonamide (ADA), 24 antibiotics, [25][26][27] adenosine and nucleic acids, [28][29][30] dopamine, 31 bacteria, 32,33 and virus. 34,35 In recent years, rapid detection of Al 3+ using AuNPs as a colorimetric sensor have been reported, in which the AuNPs' surface were functionalized by different Al 3+ recognition ligands, such as diaminodiphenyl sulfone, 36 ascorbic acid, 37 11mercaptoundecanoic acid, 38 5-mercaptomethyltetrazole, 39 poly(acrylic acid), 40 triazole ether, 41 catechol, 42 and xylenol orange.…”