Corresponding Author

Xin-hua Lin(xinhua63@163.com)


In this article, we developed a novel DNA electrochemical sensor for obtaining a current-time curve based on DNA polymerase I. The capture probes were fixed on the Au electrode by Au interacting with -SH, and then hybridized with the K-ras mutant target DNA as far as one base before the mutation site. After hybridizing the K-ras mutant or wild target DNA, the resulting assembly reacted with the dUTP-biotin in the presence of DNA polymerase I. Then avidin-HRP combined the dUTP-biotin on the electrode. The proposed electrode was applied for detection in TMB solution by electrochemical technology. The experimental results showed that the detection current of the proposed DNA electrochemical sensor is proportional to the logarithmic K-ras mutant DNA concentration (1.0×10-15 to 1.0×10-10 mol·L-1). It had high sensitivity and good selectivity.

Graphical Abstract


DNA polymerase I, K-ras point mutant gene, DNA electrochemical sensor, current-time curve

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