An efficient electrochemical method for direct screening of the mutation status of DNA base in oligonucleotides

Here we present a rapid, straightforward and low-cost electrochemical approach for the analysis of DNA base variation based on the electrocatalytic oxidation behaviors of purine and pyrimidine bases coupled with a convenient subtraction technique. The accurate oxidation signals of all DNA bases including guanine (G), adenine (A), thymine (T) and cytosine (C) were well recognized at a simple sensing interface, which paved the way for the direct screening of mutation status. Taking advantage of the current change of corresponding DNA bases, the mutation status of oligonucleotide could be identified clearly. In order to test the application value of the method, the codon 158 from the p53 tumor suppressor gene fragment was selected as the detection target. According to a convenient subtraction technique, four kinds of mutation patterns were successfully identified without the need for labeling, hybridization or enzymatic reaction procedures. Moreover, the proposed method exhibited excellent performance of ultrafast analysis within 30 min, which is remarkably faster than a variety of literature methods.