Electrochemical sensors-based phosphorus-doped carbon for determination of adenine DNA-nucleobases in living cells

Abstract

Monitoring DNA–nucleobases and their oxidized forms in living cells is regarded as a biomarker for DNA damage. Adenine (Ad) electrochemical sensor was designed based on phosphorus-doped carbon spherical eye-like structure (P-CES). Spherical electrochemical sensors oriented with abundant multiple directional gates, such as micro-, meso-pores, and open cave-like eyes may lead to design a potential sensor with fast response, low surface charge resistance, high electron diffusion, and functionalized binding active centers to accommodate Ad molecules. The P-CES hierarchically ordered sphere electrode features dense and reactive exposure sites for a variety of additional interactions and flexible mobility surfaces during the detection of Ad. The key role of the circular shape with a rugged surface, multi-hole construction, and open grooves creates an active catalyst of strong binding to the target molecules and facilitate the molecular diffusion inner/outer the electrode surface. Moreover, the doping of P atoms to the hierarchical carbon chain leads to the distortion of sp2-graphitic construction, increases the number of plane edge defects, and induces the functionalization of the abundant active sites. Thus, P-CES provides active transducing element for detection of Ad in its resources (oxidative DNA in living cells) with high sensitivity, good selectivity, excellent stability, and facile reproducibility. The fabricated P-CES shows an ultrasensitive Ad sensor with a limit of detection as low as 0.002 μmolL−1, with a wide linear range of 0.01–0.8 μmolL−1. The Ad liberated from the oxidative-DNA in living cells can be detected with high affinity and sensitivity. The Ad sensor assay can be employed for investigation of DNA damage and deliver information for diagnosis of diseases caused by cell mutation and immune system deficiency.