Amplified and in Situ Detection of Redox-Active Metabolite Using a Biobased Redox Capacitor
Amplified and in Situ Detection of Redox-Active Metabolite Using a Biobased Redox Capacitor
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DOI：
10.1021/ac302703y
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发表时间：
2013-02-19
影响因子：
7.4
通讯作者：
Payne, Gregory F.
中科院分区：
文献类型：
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作者：
Kim, Eunkyoung;Gordonov, Tanya;Payne, Gregory F.
氧化还原循环为分析物检测提供了一种放大电化学信号的机制。先前的研究表明，多种介质/穿梭体能够与一种生物基氧化还原电容器发生氧化还原循环反应，这种电容器是通过将具有氧化还原活性的儿茶酚接枝到壳聚糖膜上制备而成的。在此，我们报道利用这种儿茶酚 - 壳聚糖氧化还原电容器进行的氧化还原循环能够放大用于检测一种具有氧化还原活性的细菌代谢物的电化学信号。具体而言，我们研究了具有氧化还原活性的细菌代谢产物绿脓菌素，据报道它是机会致病菌铜绿假单胞菌的一种毒力因子和信号分子。我们证明氧化还原循环能够放大各种电化学方法（循环伏安法、计时库仑法和差分脉冲伏安法）的输出信号，并能将绿脓菌素的检测限降低至50 nM。此外，这种生物基氧化还原电容器的兼容性使得在铜绿假单胞菌培养过程中能够原位监测具有氧化还原活性的代谢产物（例如绿脓菌素）的产生。我们预计，具有氧化还原活性的毒力因子的放大输出应该能够更早地检测到由机会致病菌铜绿假单胞菌引起的危及生命的感染，而这种测量方法的“生物兼容性”应该有助于原位研究细菌氧化还原信号的时空动态。
Redox cycling provides a mechanism to amplify electrochemical signals for analyte detection. Previous studies have shown that diverse mediators/shuttles can engage in redox-cycling reactions with a biobased redox capacitor that is fabricated by grafting redox-active catechols onto a chitosan film. Here, we report that redox cycling with this catechol-chitosan redox capacitor can amplify electrochemical signals for detecting a redox-active bacterial metabolite. Specifically, we studied the redox-active bacterial metabolite pyocyanin that is reported to be a virulence factor and signaling molecule for the opportunistic pathogen P. aeruginosa. We demonstrate that redox cycling can amplify outputs from various electrochemical methods (cyclic voltammetry, chronocoulometry, and differential pulse voltammetry) and can lower the detection limit of pyocyanin to 50 nM. Further, the compatibility of this biobased redox capacitor allows the in situ monitoring of the production of redox-active metabolites (e.g., pyocyanin) during the course of P. aeruginosa cultivation. We anticipate that the amplified output of redox-active virulence factors should permit an earlier detection of life-threatening infections by the opportunistic pathogen P. aeruginosa while the "bio-compatibility" of this measurement approach should facilitate in situ study of the spatiotemporal dynamics of bacterial redox signaling.