Selective determination of cysteine by resonance light scattering technique based on self-assembly of gold nanoparticles.
The interaction between cysteine and gold nanoparticles was studied. Through the covalent combination with the -SH group and the electrostatic binding with the -NH3+ group of cysteine, gold nanoparticles can self-assemble to form a network structure, which results in greatly enhanced resonance light scattering (RLS). The experimental results demonstrate that the RLS technique offers a sensitive tool for investigations of self-assembly of nanoparticles. On the other hand, the RLS method can be applied to selectively determine cysteine with high sensitivity and simple operation. The linear range of determination of cysteine is from 0.01 to 0.25 microg/mL with the detection limit of 2.0 ng/mL (16.5 nM, 3sigma). None of the amino acids found in proteins interferes with the determination.
Li
Zheng Ping
ZP
College of Chemistry and Environmental Science, Hebei University, Baoding 071002, Hebei Province, People's Republic of China. lzpbd@mail.hbu.edu.cn
Duan
Xin Rui
XR
Liu
Cheng Hui
CH
Du
Bao An
BA
D003545:Cysteine / Q000032:analysis*; D006046:Gold; D008027:Light; D046529:Microscopy, Electron, Transmission; D036103:Nanotechnology; D010316:Particle Size; D012542:Scattering, Radiation; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet
D006046:Gold; D003545:Cysteine