Colorimetric and Label-Free Optical Detection of Pb2+ Ions via Colloidal Gold Nanoparticles

Autor: Jasmin A. Flowers, Monique J. Farrell, Gugu Rutherford, Aswini K. Pradhan
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: Biosensors, Vol 13, Iss 8, p 819 (2023)
Druh dokumentu: article
ISSN: 2079-6374
DOI: 10.3390/bios13080819
Popis: The detection of the lead heavy metal (Pb) in water is crucial in many chemical processes, as it is associated with serious health hazards. Here, we report the selective and precise colorimetric detection of Pb2+ ions in water, exploiting the aggregation and self-assembly mechanisms of glutathione (GSH)-functionalized gold nanoparticles (GNPs). The carboxyl functional groups are able to create coordination complexes with Pb2+, inducing aggregation amongst the GSH-GNPs in the presence of Pb2+ due to the chelation of the GSH ligands. The resulting aggregation amongst the GSH-GNPs in the presence of Pb2+ increases the aggregate size depending on the available Pb2+ ions, affecting the plasmonic coupling. This causes a substantial shift in the plasmon wavelength to a longer wavelength side with increasing Pb2+ concentration, resulting in a red-to-blue colorimetric or visual change, enabling the instant determination of lead content in water.
Databáze: Directory of Open Access Journals