Construction of an electrochemical genosensor based on screen-printed gold electrodes (SPGE) for detection of a mutation in the adenomatous polyposis coli gene

Abstract

Studies have well documented that mutations in the adenomatous polyposis coli gene (APC) are involved in the development of different types of cancer. Therefore, the objective of the present report was to design and construct a sensitive nanostructured genosensor able to detect specific sequences of the APC gene in order to be applied in early carcinogenesis diagnosis. We used screen-printed gold electrodes (SPGE) modified with DNA probes and mercaptoundecanoic acid chemically immobilized on a gold sensor surface. APC complementary DNA sequences were hybridized on the previously immobilized DNA probes. Besides, we tested effects of different intercalating agents, and various temperatures on the hybridization reaction to increase the sensitivity and selectivity of our device. The evaluation of these processes was carried out by means of the cyclic voltammetry technique (CV) to monitor the redox reaction of [Fe(CN)6]3−/4− on the SPGE-s. The constructed genosensor exhibited an excellent response to identify the APC gene in a concentration range from 100 pM to 100μM, with 43.92 pM as the limit of detection in the presence of doxorubicin as DNA intercalating agent. The selectivity of the device was tested by using a DNA sequence different from the APC gene, which shows negative response. Considering the importance of APC mutations in the development of tumors in the digestive, urogenital, and mammary tissues, here developed electrochemical genosensor, due to its easy management, short time of response, and high performance, may be useful for early cancer detection.