Electrochemical biosensing of DNA damage marker by MOF derived cobalt-nitrogen codoped polyhedral carbon @ platinum nanoparticle composites

In this work, we designed and synthesized a novel MOF derived cobalt-nitrogen co-doped polyhedral carbon @ platinum nanoparticle composites (Co-N/MDPC@PtNPs) to conduct electrochemical biosensing for DNA damage marker 8-Hydroxy-2’-deoxyguanosine (8-OH-dG). Co-N/MDPC@PtNPs composite was simple to prepare and doped with various elements to enhance its catalytic performance synergistically. In this work, Co-MOF was used as a substrate material, while dopamine as a carbon source, nitrogen source and bridging agent, and wrapped on the surface of MOF by self-polymerization. Platinum ions were connected to the surface of Co-MOF by the interaction of platinum ions with polydopamine. Platinum nanoparticles were obtained using ascorbic acid as a weak reducing agent. Through high temperature calcination, Co-MOF carbonization, cobalt doping and nitrogen doping can be achieved in one step. Finally, the final material - Co-N/MDPC@PtNPs was obtained by hydrochloric acid etching. The Co-N/MDPC@PtNPs-1 shows excellent performance in the detection of 8-OH-dG. The low detection limit is 0.234   µM, the wide linear range is 0.52   µM~159.02   µM, and the sensitivity is 0.346   µA/µM. The material shows good repeatability, selectivity and stability, realizing the detection of 8-OH-dG in actual urine samples and actual damaged DNA samples, providing a new method to verify the mechanism of DNA damage. It has great significance in the field of biomedicine.