Aptamer/quantum dot-based simultaneous electrochemical detection of multiple small molecules

• Published in: Analytica chimica acta Vol. 688; no. 2; pp. 99 - 103
• Main Authors: Zhang, Haixia, Jiang, Bingying, Xiang, Yun, Zhang, Yuyong, Chai, Yaqin, Yuan, Ruo
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 04.03.2011; Elsevier
• Subjects: Acid dissolution; Adenosine Triphosphate - analysis; Analytical chemistry; Aptamers; Aptamers, Nucleotide - chemistry; Assaying; ATP; Binding; Biosensing Techniques - methods; Chemistry; Cocaine - analysis; Electrochemical methods; Electrochemical Techniques - methods; Exact sciences and technology; Gold - chemistry; Labels; Limit of Detection; Mathematical analysis; Monitoring; Multi-analyte detection; Quantum Dots; Sensitivity and Specificity; Small molecules; Square wave voltammetry; Strategy; Small molecules; Multi-analyte detection; Square wave voltammetry; Quantum dots; Aptamers; Quantum dot; Chemical analysis; Electrochemical method; Immobilization; Metal ion; Voltammetry; Target; Signal; Specificity; Detection limit; Diagnosis; Monitoring; Adenosine; Sample; Triphosphates; Dissolution; Screening; Gene amplification; Multicomponent analysis; Simultaneous measurement; Strategy; Cocaine; Yield; Detection; ATP; Square wave
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2010.12.017

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.