title: Label-free amino acid detection based on nanocomposites of graphene oxide hybridized with gold nanoparticles.
abstract: Nanocomposites of graphene oxide and gold nanoparticles (GO/GNPs) were synthesized for label-free detections of amino acids. Interactions between the composites and amino acids were investigated by both naked-eye observation and optical absorption spectroscopy. The GO/GNPs composites displayed apparent color changes and absorption spectra changes in presences of amino acids including glutamate, aspartate, and cysteine. The interaction mechanisms of the composites and amino acids were discussed and explored with sulfhydryl groups and non-α-carboxylic groups on the amino acids. Sensing properties of the composites were tested, while pure gold particles were used as the control. The results suggested that the GO/GNPs composites had better linearity and stability in dose-dependent responses to the amino acids than those of the particles, especially in detections for acidic amino acids. Therefore, the nanocomposites platform can provide a convenient and efficient approach for label-free optical detections of important molecules such as amino acids.
authors.affiliation: Biosensor National Special Laboratory, Key Laboratory for Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou, 310027, PR China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Biosensor National Special Laboratory, Key Laboratory for Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou, 310027, PR China.
authors.forename: Diming
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Biosensor National Special Laboratory, Key Laboratory for Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou, 310027, PR China.
authors.forename: Yanli
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Biosensor National Special Laboratory, Key Laboratory for Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou, 310027, PR China.
authors.forename: Gang
authors.initials: G
authors.lastname: Xu
authors.affiliation: Biosensor National Special Laboratory, Key Laboratory for Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou, 310027, PR China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Yao
authors.affiliation: Biosensor National Special Laboratory, Key Laboratory for Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou, 310027, PR China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Li
authors.affiliation: Biosensor National Special Laboratory, Key Laboratory for Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou, 310027, PR China. Electronic address: qjliu@zju.edu.cn.
authors.forename: Qingjun
authors.initials: Q
authors.lastname: Liu
mesh_terms: D000596:Amino Acids / Q000032:analysis*; D003124:Colorimetry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold / Q000737:chemistry*; D006108:Graphite / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D010087:Oxides / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet / Q000295:instrumentation*; D013194:Staining and Labeling
chemical_list: D000596:Amino Acids; D010087:Oxides; D006046:Gold; D006108:Graphite
keywords: Amino acid; Gold nanoparticle (GNP); Graphene oxide (GO); Label free; Nanocomposites; Optical spectrum