title: Sensitive and selective detection of cysteine using gold nanoparticles as colorimetric probes.
abstract: We report herein the development of a highly sensitive and selective colorimetric detection method for cysteine using gold nanoparticles probes. This assay relies upon the distance-dependent optical properties of gold nanoparticles, the self-assembly of cysteine on gold nanoparticles, and the interaction of a 2:1 cysteine/Cu2+ complex. In the presence of Cu2+, cysteine could rapidly induce the aggregation of gold nanoparticles, thereby resulting in red-to-blue (or purple) color change. The concentration of cysteine can be determined by monitoring with the naked eye or a UV-vis spectrometer. The present limit of detection for cysteine is 10 nM. This method exhibits excellent selectivity for cysteine over other alpha-amino acids, glutathione, thioglycolic acid and mercaptoethyl alcohol.
authors: Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province, School of Chemistry and Materials Science, Shaanxi Normal University, Xi'an, 710062, PR China.
authors: Li
authors: L
authors: Li
authors: Baoxin
authors: B
authors: Li
mesh_terms: D000327:Adsorption; D003102:Colloids; D003116:Color; D003124:Colorimetry / Q000379:methods*; D003300:Copper / Q000737:chemistry; D003545:Cysteine / Q000032:analysis* / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D013438:Sulfhydryl Compounds / Q000737:chemistry; D013499:Surface Properties
chemical_list: D003102:Colloids; D013438:Sulfhydryl Compounds; D006046:Gold; D003300:Copper; D003545:Cysteine