Point-of-care testing of DNA damage markers-8-hydroxy-2′-deoxyguanosine based on cobalt-iron-platinum-ruthenium/N doped ordered mesoporous carbon

In this work, we achieved point of care detection of DNA damage marker 8-hydroxy-2’-deoxyguanosine (8-OH-dG) on tetrapartite metal nanoparticles loaded ordered mesoporous carbon composite nanomaterials (Co-Fex-Pt−Pd@NOMC). Nitrogen doping and co-metal loading were achieved using dopamine as nitrogen, carbon sources and metal linker. In addition, the presence of catechol groups in dopamine with strong affinity for metal ions, make the simultaneous confinement of metals inside and outside the pores of ordered mesoporous carbon. Then, Fe, Pt and Pd metal nanoparticles were introduced to interact with Co nanoparticles to form four-in-one alloy nanoparticles by oil bath and carbonisation. The finally formed Co−Fe₆-Pt−Pd@NOMC nanocomposites exhibited excellent catalytic performance for the determination of 8-OH-dG. A lower limit of detection (LOD) of 0.044 μM, a wide linear range (0.175 μM–118.375 μM) and strong stability, reproducibility and selectivity were obtained. In addition, Co−Fe₆-Pt−Pd@NOMC realised the detection of 8-OH-dG in real human urine sample. At the same time, 8-OH-dG after DNA damage and guanine damage were also studied in this work. The electrochemical response of 8-OH-dG was combined with DNA damage to verify the mechanism of DNA damage. New solutions and idea were provided for the preparation of inorganic nanocomposites for the detection of 8-OH-dG in this work.