Photoinduced Energy and Electron Transfer in Nitrogen-Doped Graphene/ZnO Nanorod Composites for Self-Powered Photoelectrochemical Aptasensing of Bis(2-ethylhexyl)phthalate

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