Platinum nanoparticles loaded carbon black: reduced graphene oxide hybrid platforms for label-free electrochemical DNA and oxidative DNA damage sensing

Carbon black-based hybrid materials have attracted great attention in the design of electrochemical sensors due to their consistent electroanalytical properties. With this in mind, for the first time, we present the preparation of platinum nanoparticles loaded carbon black:reduced graphene oxide (PtNPs/CB:rGO) hybrid platforms for label-free electrochemical DNA and DNA damage sensing. Synthesis of different hybrids was performed via microwave-assisted reduction method for the impregnation of platinum nanoparticles efficiently. These materials were characterized with X-ray diffraction analysis (XRD), Raman spectroscopy, transmission emission spectroscopy (TEM) and subsequently they were used for pencil graphite electrode modification in order to improve the characteristics of the surface. Modified electrodes were firstly applied for fish sperm DNA (fsDNA) analysis. The effect of different ratios (wt.:wt. %) of CB and rGO was investigated and it was shown that the hybrid material with 50:50 ratio had better sensitivity with a low detection limit of 0.14 mg L−1 and a good linearity to fsDNA between 1 and 200 mg L−1 (n = 3) based on guanine (G) oxidation by using differential pulse voltammetry (DPV). In order to expand this comparison, PtNPs/CB and PtNPs/rGO modified electrodes were also incorporated. Furthermore, the electroanalytical response of the hybrid material modified electrode was investigated based on the oxidation of thymine (T). Later on, oxidative DNA damage detection in the presence of Cu(II)/H2O2 reagents and protection studies in the presence of ascorbic acid were performed successfully by using electrochemical impedance spectroscopy (EIS). The study pointed out the remarkable reproducibility and sensitivity of the CB-based modification for nanoparticle decoration.