Development of a highly sensitive DNA FFTSW voltammetric genosensor based on CeO2 NPs-RGO nanocomposite

In recent years, clinical diagnosis methods developed rapidly along with discovery of new genes and their association with disease. Electrochemical DNA biosensors provide sensitivity,selectivity and low cost for detection of specific DNA sequence associated with human disease[1]. In this study, we report the construction of a novel electrochemical DNA genosensor based on reduced graphene oxide decorated with cerium oxide nanoparticles (CeO2NPs- RGO)[2]. The surface of glassy carbon electrode was modified with CeO2NPs-RGO/PANI/GCE, and characterized by scanning electron microscopy, cyclic voltammetry and electrochemical impedance spectroscopy methods. Here a novel platform was applied to detect theApolipoprotein E gene (ApoE) point mutation related to the progression of Alzheimer’s disease [3]. The ssDNA probe was immobilized into the nanocomposite, via strong interaction between CeO2 and the phosphate groups in the ssDNA backbone [4]. The fast Fourier transform square wave voltammetry was used for investigation of ssDNA probe immobilization and hybridization with target DNA. Where, the genosensor response was the current decrease of [Ru(bpy)3]2+/3+after hybridization. The genosensor showed high selectivity and sensitivity toward detection ofthe ApoE gene, with a good linear relationship between the response signal and logarithmic function of target DNA concentration in a range of 1 fM to 10 nM with a detection limit of 0.1 fM. The represented genosensor in this study can be further used for detection of target DNA in real samples.

Keywords:

electrochemical DNA genosensor , reduced graphene oxide , cerium oxide nanoparticles , Apolipoprotein E , Fourier transform square wave voltammetry