Novel Amperometric Aptasensor Based on Analyte-Induced Suppression of Enzyme Catalysis in Polymeric Bionanocomposites
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- 作者：Yingchun Fu ; Can Zou ; Lijuan Bu ; Qingji Xie ; Shouzhuo Yao
- 刊名：ACS Applied Materials & Interfaces
- 出版年：2013
- 出版时间：February 13, 2013
- 年：2013
- 卷：5
- 期：3
- 页码：934-939
- 全文大小：315K
- 年卷期：v.5,no.3(February 13, 2013)
- ISSN：1944-8252
文摘
We report on a novel label-free biosensing interface based on multifunctional polymeric bionanocomposites (PBNCs) and its application for sensitive detection of protein based on the analyte-induced suppression of enzymatic catalysis in PBNCs. Thrombin and its aptamer are adopted as a model system to construct an amperometric aptasensor. First, polydopamine-based PBNCs with glucose oxidase (GOx) entrapped at high load/activity and Au nanoparticles (AuNPs) dispersed in high abundance on the surface were prepared through a chemical/biochemical synthesis method, as proven by UV鈥搗is spectrophotometry, digital imaging, and transmission electron microscopy. Then, the PBNCs were cast-coated onto an Au electrode. The PBNC-modified Au electrode presented a high chronoamperometric sensitivity of 113 卤 2 渭A cm鈥? mM鈥? to glucose, as well as a high capability of immobilizing the aptamer through the surficial AuNPs to fabricate a label-free aptasensing interface. The binding of thrombin to the aptasensor surface significantly hindered the mass-transfer of the enzymatic substrates/products and thus suppressed the enzymatic catalysis efficiency, which produced obvious signal change through measuring the electrooxidation of enzymatically generated H2O2. The thus-prepared aptasensor could detect thrombin with a broad detection range (1鈥?00 nM), a detection limit down to 0.1 nM, and satisfactory specificity. The developed aptasensing method may find broad applications in the fields of clinical diagnosis, environmental protection, and food safety.