title: Integrated logic gate for fluorescence turn-on detection of histidine and cysteine based on Ag/Au bimetallic nanoclusters-Cu²⁺ ensemble.
abstract: By means of employing 11-mercaptoundecanoic acid (11-MUA) as a reducing agent and protecting ligand, we present straightforward one-pot preparation of fluorescent Ag/Au bimetallic nanoclusters (namely AgAuNCs@11-MUA) from AgNO3 and HAuCl4 in alkaline aqueous solution at room temperature. It is found that the fluorescence of AgAuNCs@11-MUA has been selectively quenched by Cu(2+) ions, and the nonfluorescence off-state of the as-prepared AgAuNCs@11-MUA-Cu(2+) ensemble can be effectively switched on upon the addition of histidine and cysteine. By incorporating Ni(2+) ions and N-ethylmaleimide, this phenomenon is further exploited as an integrated logic gate and a specific fluorescence turn-on assay for selectively and sensitively sensing histidine and cysteine has been designed and established based on the original noncovalent AgAuNCs@11-MUA-Cu(2+) ensemble. Under the optimal conditions, histidine and cysteine can be detected in the concentration ranges of 0.25-9 and 0.25-7 μM; besides, the detection limits are found to be 87 and 111 nM (S/N = 3), respectively. Furthermore, we demonstrate that the proposed AgAuNCs@11-MUA-based fluorescent assay can be successfully utilized for biological fluids sample analysis.
authors.affiliation: †State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Sun
authors.affiliation: †State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China.
authors.forename: Fan
authors.initials: F
authors.lastname: Yang
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: Dan
authors.initials: D
authors.lastname: Zhao
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: Chuanxia
authors.initials: C
authors.lastname: Chen
authors.affiliation: †State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China.
authors.forename: Xiurong
authors.initials: X
authors.lastname: Yang
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D003300:Copper / Q000737:chemistry*; D003545:Cysteine / Q000737:chemistry* / Q000652:urine; D005453:Fluorescence; D006046:Gold / Q000737:chemistry*; D006639:Histidine / Q000737:chemistry* / Q000652:urine; D006801:Humans; D049329:Nanostructures / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*
chemical_list: D012834:Silver; D006639:Histidine; D006046:Gold; D003300:Copper; D003545:Cysteine
keywords: 11-mercaptoundecanoic acid; Ag/Au bimetallic nanoclusters; cysteine; fluorescence turn-on; histidine; integrated logic gate