title: Bovine serum albumin-confined silver nanoclusters as fluorometric probe for detection of biothiols.
abstract: Fluorescent bovine serum albumin-confined silver nanoclusters (BSA-AgNCs) were demonstrated to be a novel and environmentally friendly probe for the rapid detection of biothiols such as cysteine (Cys), homocysteine (Hcy) and glutathione (GSH). The sensing was ascribed to the strong affinity between the mercapto group of the biothiols and the silver nanoclusters. The fluorescence intensity of BSA-AgNCs was quenched efficiently on increasing the concentration of biothiol, corresponding with a red-shift in emission wavelength. However, the fluorescence of the silver nanoclusters was almost unchanged in the presence of other α-amino acids at 10-fold higher concentrations. By virtue of this specific response, a new, simple and rapid fluorescent method for detecting biothiols has been developed. The linear ranges for Cys, Hcy and GSH were 2.0 × 10(-6) to 9.0 × 10(-5) M (R(2) = 0.994), 2.0 × 10(-6) to 1.2 × 10(-4) M (R(2) = 0.996) and 1.0 × 10(-5) to 8.0 × 10(-5) M (R(2) = 0.980), respectively. The detection limits were 8.1 × 10(-7) M for Cys, 1.0 × 10(-6) M for Hcy and 1.1 × 10(-6) M for GSH. Our proposed method was successfully applied to the determination of thiols in human plasma and the recovery was 94.83-105.24%. It is potentially applicable to protein-stabilized silver nanoclusters in a chemical or biochemical sensing system.
authors.affiliation: Department of Chemistry and Chemical Engineering, Institute of Environmental Science, Shanxi University, Taiyuan, 030006, People's Republic of China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Chen
authors.forename: Dongtao
authors.initials: D
authors.lastname: Lu
authors.forename: Zongwei
authors.initials: Z
authors.lastname: Cai
authors.forename: Chuan
authors.initials: C
authors.lastname: Dong
authors.forename: Shaomin
authors.initials: S
authors.lastname: Shuang
mesh_terms: D000818:Animals; D002417:Cattle; D005456:Fluorescent Dyes / Q000032:analysis / Q000737:chemistry*; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000032:analysis*; D013499:Surface Properties
chemical_list: D005456:Fluorescent Dyes; D013438:Sulfhydryl Compounds; D012710:Serum Albumin, Bovine; D012834:Silver
keywords: biothiols; bovine serum albumin; fluorescence; silver nanoclusters