title: Aptamer/quantum dot-based simultaneous electrochemical detection of multiple small molecules.
abstract: A novel strategy for "signal on" and sensitive one-spot simultaneous detection of multiple small molecular analytes based on electrochemically encoded barcode quantum dot (QD) tags is described. The target analytes, adenosine triphosphate (ATP) and cocaine, respectively, are sandwiched between the corresponding set of surface-immobilized primary binding aptamers and the secondary binding aptamer/QD bioconjugates. The captured QDs yield distinct electrochemical signatures after acid dissolution, whose position and size reflect the identity and level, respectively, of the corresponding target analytes. Due to the inherent amplification feature of the QD labels and the "signal on" detection scheme, as well as the sensitive monitoring of the metal ions released upon acid dissolution of the QD labels, low detection limits of 30 nM and 50 nM were obtained for ATP and cocaine, respectively, in our assays. Our multi-analyte sensing system also shows high specificity to target analytes and promising applicability to complex sample matrix, which makes the proposed assay protocol an attractive route for screening of small molecules in clinical diagnosis.
authors.affiliation: Key Laboratory on Luminescence and Real-Time Analysis, Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
authors.forename: Haixia
authors.initials: H
authors.lastname: Zhang
authors.forename: Bingying
authors.initials: B
authors.lastname: Jiang
authors.forename: Yun
authors.initials: Y
authors.lastname: Xiang
authors.forename: Yuyong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Yaqin
authors.initials: Y
authors.lastname: Chai
authors.forename: Ruo
authors.initials: R
authors.lastname: Yuan
mesh_terms: D000255:Adenosine Triphosphate / Q000032:analysis; D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D003042:Cocaine / Q000032:analysis; D055664:Electrochemical Techniques / Q000379:methods*; D006046:Gold / Q000737:chemistry; D057230:Limit of Detection; D045663:Quantum Dots; D012680:Sensitivity and Specificity
chemical_list: D052157:Aptamers, Nucleotide; D006046:Gold; D000255:Adenosine Triphosphate; D003042:Cocaine