Graphene-Oxide and Ionic Liquid Modified Electrodes for Electrochemical Sensing of Breast Cancer 1 Gene

Abstract

Graphene-oxide and ionic liquid composite-modified pencil graphite electrodes (GO-IL-PGEs) were developed and used as a sensing platform for breast cancer 1 (BRCA1) gene detection. The characterization of GO-IL modified electrodes was executed by scanning electron microscopy (SEM), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The nucleic-acid hybridization was monitored by a differential pulse voltammetry (DPV) technique by directly measuring the guanine oxidation signal without using any indicator. The effects of the IL concen-tration, the probe concentration, and the hybridization time were optimized to the biosensor re-sponse. The limit of detection (LOD) was calculated in the concentration range of 2–10 μg/mL for the BRCA1 gene and found to be 1.48 μg/mL. The sensitivity of the sensor was calculated as 1.49 μA.mL/μg.cm2. The developed biosensor can effectively discriminate the complementary target sequence in comparison to a three-base-mismatched sequence or the non-complementary one.