Nano-p–n junction heterostructures enhanced TiO2 nanobelts biosensing electrode

6-Phosphate aminopurine ( 6 PA), a purine analog, is usually used in clinical anticancer treatment and biochemical research. Up to now, to the best of our knowledge, no literature about the electrochemical behaviors of 6 PA has been reported. In this study, nano-p–n junction heterostructures based on TiO 2 nanobelts were produced by the assembly of p-type semiconducting NiO nanoparticles onto the n-type surface-coarsened TiO 2 nanobelts. The electrochemical behaviors of 6 PA were investigated by different voltammetric techniques in a phosphate buffer solution of pH 7.4 using the heterostructures as the sensing electrode. Compared with single-phase TiO 2 nanobelt electrodes, the resulting chemically modified electrodes exhibited higher surface accumulation ability and enhanced electrocatalytic activities in the oxidation for 6 PA, with an irreversible oxidation peak at +0.91 V. It is proposed that the nano-p–n junction heterostructures played an important role in the enhancement of charge transport in the sensing electrodes. The results suggest that the nanoengineered TiO 2 nanobelts might be a promising candidate for biosensing applications of nucleic acid drugs that will be of significance to diagnostic medicine and molecular biology research.