Glycosylation of Quinone-Fused Polythiophene for Reagentless and Label-Free Detection of E. coli

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• 作者：Fen Ma ; Abdul Rehman ; Haiying Liu ; Jingtuo Zhang ; Shilei Zhu ; Xiangqun Zeng
• 刊名：Analytical Chemistry
• 出版年：2015
• 出版时间：February 3, 2015
• 年：2015
• 卷：87
• 期：3
• 页码：1560-1568
• 全文大小：449K
• ISSN：1520-6882

文摘

In this report, a new polythiophene interface is fabricated containing fused quinone moieties which are then glycosylated to form a carbohydrate platform for bacterial detection. Very importantly, this interface can be used for label-free and reagentless detection, both by electrochemical and Quartz Crystal Microbalance (QCM) transducers and by using the direct pili-mannose binding as well as Concanavalin A (Con A) mediated lipopolysaccharides (LPS)-mannose binding. The conductive polymer鈥檚 unique collective properties are very sensitive to very minor perturbations, which result in significant changes of electrical conductivity and providing amplified sensitivity and improved limits of detection (i.e., 25 cell/mL for electrochemical sensor and 50 cells/mL for QCM sensor), a widened logarithmic range of detection (i.e., 3鈥? for pili-mannose binding and 2鈥? for Con A mediated binding), high specificity and selectivity, and an extraordinary reliability by a mechanism of internal validation. With these analytical performances, the described biosensor is envisaged for being capable of differentiating Gram-negative bacterial strain and species, for many important applications.