title: A colorimetric and fluorometric dual-signal sensor for arginine detection by inhibiting the growth of gold nanoparticles/carbon quantum dots composite.
abstract: A bidimensional optical sensing platform which combines the advantages of fluorescence and colorimetry has been designed for arginine (Arg) detection. The system was established by monitoring the influence of Arg on the growth of gold nanoparticles/carbon quantum dots (Au/CQDs) composite, and the CQDs synthesized by ethylene glycol were used as the reducing and stabilizing agent in this paper. Considering that Arg is the only amino acid with guanidine group and has the highest isoelectric point (pI) value at 10.76, Arg would carry positive charges at pH 7.4. Consequently, the positively charged guanidine group of Arg could attract AuCl4-and CQDs through electrostatic interaction, which inhibited the growth of Au/CQDs composite. Thereby, the color of the system almost did not change and the fluorescence quenching of CQDs was prevented in the presence of Arg. Based on the color change a low detection limit for Arg was 37nM, and a detection limit of 450nM was obtained by fluorescence spectroscopy. Moreover, this dual-signal sensor also revealed excellent selectivity toward Arg over other amino acids. Besides, Arg can be detected in urine samples with satisfactory results, which demonstrate the potential applications for real analysis.
authors.affiliation: Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
authors.forename: Ting
authors.initials: T
authors.lastname: Liu
authors.affiliation: Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
authors.forename: Na
authors.initials: N
authors.lastname: Li
authors.affiliation: Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
authors.forename: Jiang Xue
authors.initials: JX
authors.lastname: Dong
authors.affiliation: Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China; College of Chemistry and Pharmaceutical Engineering, Key Laboratory of Green Catalysis of Higher Education Institutes of Sichuan, Sichuan University of Science and Engineering, Zigong 643000, PR China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
authors.forename: Yu Zhu
authors.initials: YZ
authors.lastname: Fan
authors.affiliation: Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
authors.forename: Shu Min
authors.initials: SM
authors.lastname: Lin
authors.affiliation: Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China. Electronic address: luohq@swu.edu.cn.
authors.forename: Hong Qun
authors.initials: HQ
authors.lastname: Luo
authors.affiliation: Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China. Electronic address: linb@swu.edu.cn.
authors.forename: Nian Bing
authors.initials: NB
authors.lastname: Li
mesh_terms: D001120:Arginine / Q000652:urine*; D015374:Biosensing Techniques / Q000379:methods; D002244:Carbon / Q000737:chemistry*; D003124:Colorimetry / Q000379:methods; D006046:Gold / Q000737:chemistry*; D006801:Humans; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D045663:Quantum Dots / Q000737:chemistry* / Q000648:ultrastructure; D013050:Spectrometry, Fluorescence / Q000379:methods
chemical_list: D002244:Carbon; D006046:Gold; D001120:Arginine
keywords: Arginine; Carbon quantum dots; Gold nanoparticles; Isoelectric point