title: Chemical etching of bovine serum albumin-protected Au25 nanoclusters for label-free and separation-free detection of cysteamine.
abstract: This study describes a novel Au nanocluster-based fluorescent sensor for label-free, separation-free and selective detection of cysteamine (CSH). The sensing mechanism is based on CSH etching-induced fluorescence quenching of the bovine serum albumin-protected Au25 nanoclusters (BSAGNCs). A series of characterizations is carried out towards a better understanding of the CSH-induced fluorescence quenching of the BSAGNCs. It is found that CSH can etch the Au25 nanoclusters, exhibiting the potent etching activity. Other thiol-containing compounds such as glutathione and cysteine and other 19 natural amino acids do not interfere with such CSH-induced etching process. The decreases in fluorescence intensity of the BSAGNCs allow sensitive detection of free CSH in the range of 500-10,000nM. The detection limit for CSH is 150nM (S/N=3). The spiked human serum samples can be analyzed with satisfactory results.
authors.affiliation: Research Center for Bioengineering and Sensing Technology, Beijing Key Laboratory for Bioengineering and Sensing Technology, University of Science and Technology Beijing, Beijing 100083, PR China.
authors.forename: Tong
authors.initials: T
authors.lastname: Shu
authors.affiliation: Research Center for Bioengineering and Sensing Technology, Beijing Key Laboratory for Bioengineering and Sensing Technology, University of Science and Technology Beijing, Beijing 100083, PR China. Electronic address: sulei@ustb.edu.cn.
authors.forename: Lei
authors.initials: L
authors.lastname: Su
authors.affiliation: Research Center for Bioengineering and Sensing Technology, Beijing Key Laboratory for Bioengineering and Sensing Technology, University of Science and Technology Beijing, Beijing 100083, PR China.
authors.forename: Jianxing
authors.initials: J
authors.lastname: Wang
authors.affiliation: College of Engineering and Computing, Florida International University, 10555 West Flagler Street, Miami, FL 33174, USA.
authors.forename: Chenzhong
authors.initials: C
authors.lastname: Li
authors.affiliation: Research Center for Bioengineering and Sensing Technology, Beijing Key Laboratory for Bioengineering and Sensing Technology, University of Science and Technology Beijing, Beijing 100083, PR China. Electronic address: zhangxueji@ustb.edu.cn.
authors.forename: Xueji
authors.initials: X
authors.lastname: Zhang
mesh_terms: D000596:Amino Acids / Q000737:chemistry; D015374:Biosensing Techniques / Q000379:methods*; D003543:Cysteamine / Q000302:isolation & purification*; D005456:Fluorescent Dyes / Q000737:chemistry; D005978:Glutathione / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry
chemical_list: D000596:Amino Acids; D005456:Fluorescent Dyes; D012710:Serum Albumin, Bovine; D003543:Cysteamine; D006046:Gold; D005978:Glutathione
keywords: Cysteamine; Gold nanocluster; Nanocluster-based biosensor; Thiol etching; Thiol sensor