Colorimetric detection of Cr3+ based on gold nanoparticles functionalized with 4-mercaptobenzoic acid

Abstract

Herein, we report the construction of a colorimetric probe used to detecting Cr 3+ ions in aqueous solution based on functionalized gold nanoparticles. We investigated 4-mercaptobenzoic acid, 4-nitrobenzenethiol, and a mixture of 4-mercaptobenzoic acid and 4-nitrobenzenethiol as ligands for Cr 3+ ions to functionalize the gold nanoparticles, respectively. The results showed that the three probes were all aggregated in the presence of Cr 3+ ions, which induces a color change from ruby to violet. Moreover, gold nanoparticles modified with 4-mercaptobenzoic acid exhibit a higher response toward Cr 3+ than the two other probes, which can be detected by the naked eye and UV-vis absorption spectroscopy. The detection time was rapid (within 25 min). A linear relationship was obtained from 20 to 25 μM between the ratio of the absorbance observed at 635 nm and 520 nm (A635 nm/A520 nm) with the limit of detection was 5 × 10 −6 M. This method exhibited excellent selectivity for Cr 3+ ions over other tested heavy metal ions, anions, and organic molecules in the absence of another shielding reagent of metal ion. The system was successfully utilized to detect Cr 3+ ions in simulated samples.

Diethylenetriaminepentaacetic Acid-Functionalized Gold Nanoparticles for the Detection of Toxic Chromium Assisted by a Machine-Learning Approach

“…DTDTPA consists of two thiol groups which can covalently link with GNP and add an advantage due to the presence of a hard Odonor containing carboxylic acid moieties, 52 which can efficiently complex with the chromium ions. 43 The structural information of DTDTPA, explored by FTIR and LC−MS analyses (as shown in Figures S2 and S3, respectively) showed good agreement with the previously reported data, confirming the successful synthesis of DTDTPA. 44,53,54 The citratestabilized red-color GNP solution showed an absorption band (λ max ) centered at ∼520 nm due to the collective oscillation of the conduction electrons.…”

Citrate-Capped Gold Nanoparticle as a Ligand for Chromium(III) Ion: Optimization and Its Application in Contaminated Tap Water

“…4, which is shown the absorbance at 650 nm of gold nanoparticles solution (after aggregation) related to time in seconds. Our findings on this kinetics are agreed upon by other researchers who worked on the kinetics of gold nanoparticle aggregation [23].…”

Semishell Janus Nanoparticle-Enabled pH-Responsive Rod-Shaped Assembly for Photothermal Therapy

“…Meanwhile, the characteristic absorption peak of thiol groups (−SH) at 2524 cm –1 was observed in the FTIR spectrum of pure 4-MBA but disappeared in that of the 4-MBA-semishell NPs. This evidence confirms that 4-MBA had been successfully grafted onto the bare gold surface of 4-MBA-semishell NPs through thiol-gold bonding …”