Davis Frank, Hughes Margaret A, Cossins Andrew R, Higson Séamus P J
Cranfield Health, Cranfield University, Silsoe MK45 4DT, United Kingdom.
Anal Chem. 2007 Feb 1;79(3):1153-7. doi: 10.1021/ac061070c.
A simple and novel electrochemical biosensor is described for differentiating between differing gene sequences on the basis of DNA hybridization events. Polyethylenimine-modified screen-printed carbon electrodes were used to immobilize single-stranded PCR fragments from plasmid DNA from the gene for pyruvate kinase. AC impedimetric measurements were first performed on these systems in buffer and then upon exposure to single-stranded DNA. When the electrode and solution DNA were complementary, a large drop in impedance was measured. Complementary DNA could be clearly detected at concentrations down to 1 fg/mL. Higher concentrations gave faster hybridization with saturation occurring at levels above 1 ng/mL. Responses were much lower upon exposure to noncomplementary DNA, even at higher concentrations, with the sensor showing a high degree of selectivity. This sensor format offers great promise for many DNA hybridization applications and lends itself to mass fabrication.
描述了一种简单新颖的电化学生物传感器，用于基于DNA杂交事件区分不同的基因序列。使用聚乙烯亚胺修饰的丝网印刷碳电极固定来自丙酮酸激酶基因的质粒DNA的单链PCR片段。首先在缓冲液中对这些系统进行交流阻抗测量，然后在暴露于单链DNA后进行测量。当电极和溶液中的DNA互补时，测量到阻抗大幅下降。在低至1 fg/mL的浓度下可以清晰检测到互补DNA。较高浓度下杂交速度更快，在高于1 ng/mL的水平时达到饱和。即使在较高浓度下，暴露于非互补DNA时响应也低得多，该传感器显示出高度的选择性。这种传感器形式在许多DNA杂交应用中具有很大的前景，并且适合大规模制造。
