Self-Powered Photoelectrochemical Aptasensor for Oxytetracycline Cathodic Detection Based on a Dual Z-Scheme WO₃/g-C₃N₄/MnO₂ Photoanode

Abstract

With the high sensitivity and anti-interference provided by a dual Z-scheme structure photoanode and a two-electrode system, a high-performance self-powered photoelectrochemical (PEC) aptasensor for oxytetracycline (OTC) detection was established in this work. Graphitic carbon nitride (g-C3N4) with excellent photoelectric properties was used to be combined with WO3 and MnO2 to form a kind of dual Z-scheme heterojunction. The designed unique structure and the complementary performances of the three materials collectively guaranteed the highly stable photocurrent output of the photoanode due to the wide range of light absorption and the high separation rate of electron–hole pairs. The aptamer-based cathode modified with reduced graphene oxide (rGO) and Au nanoparticles (Au NPs) provided high conductivity and aptamer-binding sites, which brought excellent selective recognition of OTC as well as the self-powered capacity by receiving electrons from the photoanode. In the PEC sensing of OTC, the device presented a wide detection range from 1 pM to 150 nM and a low detection limit of 0.1 pM. Besides, the developed PEC aptasenor showed good selectivity, reproducibility, and stability, so as to be applied to real samples. The proposed PEC sensing method can be considered an effective and promising direction for the detection of antibiotics in the future.

Carbon Dots and Eu3+ Hybrid-Based Ratiometric Fluorescent Probe for Oxytetracycline Detection

“…Owing to the strong antibacterial activity, oxytetracycline (OTC) has been widely used in livestock farming to prevent and treat bacterial diseases. − However, the OTC residues present in the animal-derived food and environmental water sources due to the overuse of OTC seriously harm to human health. − Several traditional approaches have been developed to detect OTC, including high-performance liquid chromatography, enzyme-linked immunosorbent assay, capillary electrophoresis, and electrochemical methods. − However, these methods suffer from intricate operation procedures, a requirement for trained operators, high cost, and low repeatability. Thus, it is essential to develop efficient and precise methods to detect OTC rapidly and accurately.…”

Construction and excellent photoelectric synergistic anticorrosion performance of Z-scheme carbon nitride/tungsten oxide heterojunctions

“…17 The matching energy bands of g-C 3 N 4 and WO 3 can form Z-scheme heterojunctions to take full advantage of solar energy to generate photogenerated electrons for the electrochemical protection of the coupling metals. 18 The Z-scheme heterojunction's charge transfer path ensures the rapid unidirectional transfer of electrons while retaining the strong reduction of electrons, which significantly improves the photocathode protection effect. In addition, g-C 3 N 4 as an organic substance contains π-bonds and polar functional groups.…”

Catalytic Decomposition of the Hole-Derived H2O2 by AgBiS2@Ag Nanozyme to Enhance the Photocurrent of Z-Scheme BiVO4/ZnIn2S4 Photoelectrode in Microfluidic Immunosensing Platform

“…Exploiting photoactive materials with preeminent stability and photocurrent intensity plays an important role in the construction process of a high-performance PEC sensor. , Nevertheless, traditional photocatalysts such as transition metal oxides, metal sulfide, and perovskite oxides semiconductors have the intrinsic drawbacks of electron transfer tardiness and low light utilization, which inevitably restricts the photoelectric performance of these materials. − Therefore, it is still urgent to explore photocatalysts with outstanding charge migration capacity and efficient visible-light response. Bismuth vanadate (BiVO 4 ) has aroused great attention due to a moderate band gap (about 2.4 eV) and good chemical stability.…”