title: A "turn-on" fluorescent sensor for ultrasensitive detection of melamine based on a new fluorescence probe and AuNPs.
abstract: In this study, we synthesized a new fluorescence probe which was used to detect melamine by coupling with gold nanoparticles (AuNPs). The new fluorescence probe has good optical stability and high fluorescence intensity, which can greatly improve the detection sensitivity. Compared to the traditional fluorophore, it is less dependent on the pH value. It has a very strong fluorescence emission peak at 550 nm, which has larger overlap with the absorption peak of AuNPs. When the probe incubates with the AuNPs, the fluorescence of the probe can be effectively quenched by AuNPs. Adding melamine into a probe-AuNPs mixture caused aggregation of AuNPs and released the adsorbed probe; the fluorescence intensity of the probe was recovered. By measuring the changes of the fluorescence intensity of the probe, the detection of melamine can be realized. Under optimized conditions, the linear response to melamine is in the range of 1.0 × 10(-8)-4.0 × 10(-6) mol L(-1) and lowers the detection limit down to 3.0 nmol L(-1) with the sensor. This method can detect melamine in milk and milk-based productions.
authors.affiliation: Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, PR China. zhangyy@hunnu.edu.cn.
authors.forename: Qiujun
authors.initials: Q
authors.lastname: Lu
authors.forename: Jiangna
authors.initials: J
authors.lastname: Zhao
authors.forename: Shanyan
authors.initials: S
authors.lastname: Xue
authors.forename: Peng
authors.initials: P
authors.lastname: Yin
authors.forename: Youyu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Shouzhuo
authors.initials: S
authors.lastname: Yao
mesh_terms: D000818:Animals; D005456:Fluorescent Dyes / Q000737:chemistry*; D005506:Food Contamination / Q000032:analysis*; D006046:Gold / Q000737:chemistry*; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008892:Milk / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods; D014227:Triazines / Q000032:analysis*
chemical_list: D005456:Fluorescent Dyes; D014227:Triazines; D006046:Gold; C011907:melamine