Nanoporous gold electrode prepared from two-step square wave voltammetry (SWV) and its application for electrochemical DNA biosensing of lung resistance related protein (LRP) gene

In this work, considering with the existing inherent deficiencies in the preparation of current porous gold electrode, uniform and ordered nanoporous gold (NPG) electrode prepared from two-step square wave voltammetry (SWV) was developed. The formation process, morphology and electrochemical properties were carefully characterized. Compared with naked gold electrode, NPG electrode illustrated the characteristics of improved surface area, enhanced signal response and repeatable preparation. Using NPG electrode as active surface, a new electrochemical DNA biosensor was established for the detection of lung resistance related protein (LRP) gene combined with thionine as an electroactive indicator. Likewise, the electrochemical behavior of the interaction between thionine and DNA molecular could be improved on this NPG electrode to enhance the detection performance of LRP gene. In a wide range from 200 f. to 7.5nM, the logarithm concentration of LRP gene was linear with the reduction peak current of thionine, and a detection limit of 60 f. was obtained. As a result, it had provided a good basis of experimental research for LRP gene detection. Meanwhile, this technique could be expected to be applied into the real analysis of LRP gene in clinical peripheral blood samples.