title: Label-free turn-on fluorescent detection of melamine based on the anti-quenching ability of Hg 2+ to gold nanoclusters.
abstract: In this work, we proposed a facile, environmentally friendly and cost-effective assay for melamine with BSA-stabilized gold nanoclusters (AuNCs) as a fluorescence reader. Melamine, which has a multi-nitrogen heterocyclic ring, is prone to coordinate with Hg(2+). This property causes the anti-quenching ability of Hg(2+) to AuNCs through decreasing the metallophilic interaction between Hg(2+) and Au(+). By this method, detection limit down to 0.15 µM is obtained, which is approximately 130 times lower than that of the US food and Drug Administration estimated melamine safety limit of 20 µM. Furthermore, several real samples spiked with melamine, including raw milk and milk powder, are analyzed using the sensing system with excellent recoveries. This gold-nanocluster-based fluorescent method could find applications in highly sensitive detection of melamine in real samples.
authors.affiliation: State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China; University of Chinese Academy of Sciences, Beijing 100039, China.
authors.forename: Haichao
authors.initials: H
authors.lastname: Dai
authors.forename: Yan
authors.initials: Y
authors.lastname: Shi
authors.forename: Yilin
authors.initials: Y
authors.lastname: Wang
authors.forename: Yujing
authors.initials: Y
authors.lastname: Sun
authors.forename: Jingting
authors.initials: J
authors.lastname: Hu
authors.forename: Pengjuan
authors.initials: P
authors.lastname: Ni
authors.forename: Zhuang
authors.initials: Z
authors.lastname: Li
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000379:methods*; D002417:Cattle; D005456:Fluorescent Dyes / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D057230:Limit of Detection; D008628:Mercury / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry; D008892:Milk / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry; D014227:Triazines / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D005456:Fluorescent Dyes; D014227:Triazines; D012710:Serum Albumin, Bovine; D006046:Gold; D008628:Mercury; C011907:melamine
keywords: Coordination; Fluorescent method; Gold nanoclusters; Melamine; Metallophilic Hg(2+)–Au(+) interactions