Photoinduced Energy\nand Electron Transfer in Nitrogen-Doped\nGraphene/ZnO Nanorod Composites for Self-Powered Photoelectrochemical\nAptasensing of Bis(2-ethylhexyl)phthalate

Bis(2-ethylhexyl) phthalate (DEHP) is widely found in\nthe environment\nand is recognized as an endocrine disrupter, which gives rise to concern\nfor the functioning of ecosystems and human health. Given the wide\nrange of DEHP present in the surroundings and its harmfulness, it\nis crucial to develop methods for identifying DEHP in a highly sensitive,\ntimely, and low-cost way. Herein, we describe a photoelectrochemical\n(PEC) method using one-dimensional ZnO nanorods and two-dimensional\nnitrogen-doped graphene (N-graphene/ZnO nanorods) as the photoactive\nmaterial and aptamer, respectively, against DEHP as the biorecognition\nelement for detecting DEHP. To improve light absorption ability, regular\nZnO nanorods were prepared by a simple hydrothermal method. Coupling\nwith N-graphene that exhibits more chemical active sites and faster\nelectron transfer, N-graphene/ZnO nanorods demonstrated a higher carrier\ndensity by the Mott–Schottky curve and an efficient charge\ncarrier separation by photoluminescence spectra. The sensitivity of\nPEC is increased due to the properties of N-graphene/ZnO nanorods.\nThe constructed sensing platform has shown excellent sensing performance\nin detecting DEHP. Moreover, the photocurrent exhibited a linear relationship\nwith the logarithm of DEHP concentration within the range of 5.0 ×\n10<sup>–11</sup>–1.0 × 10<sup>–7</sup> mol/L,\nand an estimated limit of detection was determined as 1.4 × 10<sup>–11</sup> mol/L. At the same time, satisfactory results were\nachieved in real soil samples and further verified by gas chromatography–mass\nspectrometry. Therefore, the PEC aptasensor has been suggested to\nserve as a promising tool for monitoring the presence of DEHP.