Yan Wei, Chen Xiaojun, Li Xinghua, Feng Xiaomiao, Zhu Jun-Jie
Key Laboratory of Analytical Chemistry for Life Science (MOE), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China.
J Phys Chem B. 2008 Jan 31;112(4):1275-81. doi: 10.1021/jp0765594. Epub 2008 Jan 9.
The silver chloride@polyaniline (PANI) core-shell nanocomposites (AgCl@PANI) combined with Au nanoparticles (AuNPs) were used to prepare the AuNPs-AgCl@PANI hybrid material. A novel sensitive label-free low-density lipoprotein (LDL) electrochemical biosensor was fabricated by adsorption of antibody to apolipoprotein B-100 (aopB-100) on an AuNPs-AgCl@PANI-modified glassy carbon (GC) electrode. The hybrid material could provide surface for high antibody loading due to its large surface-to-volume ratio. Since each LDL has an apoB-100 on its phospholipids coat, they could be bonded to the electrode surface through the specific antibody-antigen reaction. Electrochemical impedance spectroscopy (EIS) was used to characterize the recognition of LDL. The negative charges carried by LDL phospholipids coat would block the electron transfer of the [Fe(CN)6]3-/4- redox couple severely. In addition, the conductivity of LDL is very poor, so small amounts of LDL on the electrode could result in great change in the electron-transfer resistance (Ret). The biosensor exhibited a highly sensitive response to LDL with a detection limit of 0.34 pg/mL, and some factors that would affect the performance of the biosensor were studied, such as incubation time and temperature.
将氯化银@聚苯胺（PANI）核壳纳米复合材料（AgCl@PANI）与金纳米颗粒（AuNPs）相结合，制备了AuNPs-AgCl@PANI杂化材料。通过将载脂蛋白B-100（aopB-100）抗体吸附在AuNPs-AgCl@PANI修饰的玻碳（GC）电极上，构建了一种新型的灵敏无标记低密度脂蛋白（LDL）电化学生物传感器。该杂化材料因其较大的表面体积比，可为高抗体负载提供表面。由于每个LDL在其磷脂外壳上都有一个apoB-100，它们可以通过特异性抗体-抗原反应结合到电极表面。采用电化学阻抗谱（EIS）对LDL的识别进行表征。LDL磷脂外壳携带的负电荷会严重阻碍[Fe(CN)6]3-/4-氧化还原对的电子转移。此外，LDL的电导率很差，因此电极上少量的LDL会导致电子转移电阻（Ret）发生很大变化。该生物传感器对LDL表现出高度灵敏的响应，检测限为0.34 pg/mL，并研究了一些会影响生物传感器性能的因素，如孵育时间和温度。
