Zuo Shao-Hua, Zhang Ling-Fan, Yuan Hui-Hui, Lan Min-Bo, Lawrance Geoffrey A, Wei Gang
Research Center of Analysis & Test and Institute of Advanced Materials, East China University of Science and Technology, Shanghai 200237, PR China.
Bioelectrochemistry. 2009 Feb;74(2):223-6. doi: 10.1016/j.bioelechem.2008.09.004. Epub 2008 Sep 25.
A simple, polishable and renewable DNA biosensor was fabricated based on a zirconia modified carbon paste electrode. Zirconia was mixed with graphite powder and paraffin wax to produce the paste for the electrode, and response-optimized at 56% graphite powder, 19% ZrO(2) and 25% paraffin wax. An oligonucleotide probe with a terminal 5'-phosphate group was attached to the surface of the electrode via the strong affinity of zirconia for phosphate groups. DNA immobilization and hybridization were characterized by cyclic voltammetry and differential pulse voltammetry, using methylene blue as indicator. Examination of changes in response with complementary or non-complementary DNA sequences showed that the developed biosensor had a high selectivity and sensitivity towards hybridization detection (< or =2x10(-10) M complementary DNA detectable). The surface of the biosensor can be renewed quickly and reproducibly (signal RSD+/-4.6% for five successive renewals) by a simple polishing step.
基于氧化锆修饰的碳糊电极制备了一种简单、可抛光且可再生的DNA生物传感器。将氧化锆与石墨粉和石蜡混合以制备电极糊剂，并在56%石墨粉、19% ZrO₂和25%石蜡的条件下进行响应优化。通过氧化锆对磷酸基团的强亲和力，将具有5'-磷酸末端基团的寡核苷酸探针连接到电极表面。以亚甲基蓝为指示剂，采用循环伏安法和差分脉冲伏安法对DNA固定和杂交进行表征。对互补或非互补DNA序列响应变化的检测表明，所开发的生物传感器对杂交检测具有高选择性和灵敏度（可检测到≤2×10⁻¹⁰ M的互补DNA）。通过简单的抛光步骤，生物传感器的表面可以快速且可重复地更新（连续五次更新的信号相对标准偏差±4.6%）。
