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• Channel current is 100 times higher than photocurrent. • This OPECT aptasensor amplifies the gate signal output 800 times through channel. • The introduction light avoids using gate voltages further reducing power consumption. • This OPECT aptasensor realizes highly sensitive detection for T-2 toxin in milk samples. Detection of T-2 toxin is of great significance to environment and human health, as T-2 toxin is one of the main toxins that contaminate crops, stored grain and other food. Herein, a zero-gate-bias organic photoelectrochemical transistor (OPECT) sensor was proposed based on nanoelectrode arrays as gate photoactive materials which can result in the accumulation of photovoltage and preferable capacitance leading to better sensitivity of the OPECT. For comparison, the channel current of OPECT was 100 times higher than photocurrent of conventional photoelectrochemical (PEC) attributing to remarkable signal amplification of OPECT. It was also found that the detection limit of OPECT aptasensor was as low as 28.8 pg/L, lower than 0.34 ng/L of the conventional PEC method, further indicating the advantage of the OPECT devices in T-2 toxin determination. This research has been successfully applied in real sample detection which provided a general platform of OPECT for food safety analysis. [ABSTRACT FROM AUTHOR]

Over use of lincomycin (LIN) as antibiotic in animals can lead to multiple harmful impacts to public health, thus detection of LIN at trace level in milk and chicken sample matrixes is vital. In this work, Zinc phthalocyanine nanoparticles sensitized MoS 2 (ZnPc/MoS 2) was firstly developed as a novel photocathode material combined with nitrogen-doped graphene-loaded TiO 2 nanoparticles (TiO 2 /NG) as photoanode material to construct a dual-photoelectrode photofuel cell (PFC). The as-prepared membrane/mediator-free PFC achieved excellent output performance that the maximum power density (P max) reached 11.83 μW cm−2. Specific aptamers are adopted as LIN recognition elements, the as-proposed self-powered aptasensor for LIN exhibited a linear scope in 10−11 –10−5 mol L−1 along with a low detection limit (3S/N) of 3.33 pmol L−1. Consequently, such high-power density dual-photoelectrode PFC aptasensor may be a reassuring candidate electrochemical sensor for the detection of trace contamination in food samples. [Display omitted] • Zinc phthalocyanine sensitized MoS 2 was developed as a novel photocathode material. • The maximum power density reached 11.83 μW cm−2 • A dual-photoelectrode PFC lincomycin aptasensor was successfully established. • This aptasensor can be applied to detect lincomycin in milk and chicken. [ABSTRACT FROM AUTHOR]

Exploring efficient methods for microcystin-LR (MC-LR) detection is of great significance for protecting ecological environment safety and human health. Herein, an MC-LR aptasensor was fabricated based on the synergistic amplified cathodic electrochemiluminescence (ECL) of the functional nanocomposite of ZnO quantum dots decorated B, N co-doped graphene (BNG/ZnO). With K 2 S 2 O 8 as co-reactant, a robust cathodic ECL emission of BNG/ZnO was observed based on the synergistic catalytic effect of B, N in graphene. Interestingly, the ECL intensity of BNG/ZnO nanocomposite was 1.8, 2.9, and 5.4 times enhanced than N-doped graphene/ZnO, B-doped graphene/ZnO, and graphene/ZnO, which was because of the difference in the electronegativity of B, C, and N could generate a unique synergistic effect to make graphene-based materials realizing signal amplification. Subsequently, a novel cathodic ECL aptasensor was constructed for sensitive and selective detection of MC-LR with aptamer as the recognition element and BNG/ZnO as the luminous reagent. Under optimized conditions, the linear range of the prepared cathodic ECL aptasensor for MC-LR detection was 0.1–5000 pM, the detection limit was 0.03 pM (S/N = 3). At the same time, the proposed aptasensor had good selectivity and stability and showed satisfactory results in actual water sample analysis. • A novel cathodic ECL aptasensor for MC-LR detection was fabricated based on BNG/ZnO. • The ECL intensity of BNG/ZnO was enhanced than that of BG/ZnO, NG/ZnO, and ZnO QDs. • Synergistic catalysis of B, N in graphene resulted in the amplification ECL of ZnO. • The proposed ECL aptasensor has low detection limit, good selectivity and stability. • Satisfactory results were obtained in the analysis of actual water sample. [ABSTRACT FROM AUTHOR]

Ciprofloxacin (CIP) in milk has a harmful effect on human health, it's important to conduct ultra-sensitive selective detection of ciprofloxacin. Herein, an ultrasensitive and selective organic photoelectrochemical transistor (OPECT) CIP aptasensor was constructed using Ti 3 C 2 /TiO 2 composites as gate photoactive materials. Compared with Ti 3 C 2 , TiO 2 , and Ti 3 C 2 /TiO 2 mixed by physical, Ti 3 C 2 /TiO 2 composites exhibits larger capacitance and the OPECT intensity is 3 times of Ti 3 C 2 , 2 times of Ti 3 C 2 /TiO 2 mixed by physical and TiO 2 , which attributed to higher capacitance of Ti 3 C 2 /TiO 2 composites provides high electrostatic charge storage capacity and leads to effective gating, induces more electronic charge in the channel and larger drain currents. Exemplified by CIP as target, the developed sensor achieves sensitive detection with linear range from 3 ng/L to 3 mg/L, detection limit is 1 ng/L. This work completed the detection in real samples, which lays a foundation for the construction of OPECT food safety analysis and detection platform. • TiO 2 /Ti 3 C 2 composites was prepared by one-pot solvent hydrothermal method. • Higher capacitance of TiO 2 /Ti 3 C 2 composites greatly improves the sensitivity of OPECT aptasensor. • A sensitive and stable OPECT aptasensor for CIP detection was fabricated. • This OPECT aptasensor presented excellent performance than traditional PEC aptasensor. [ABSTRACT FROM AUTHOR]

The residual of atrazine (ATZ) can disrupt the production of testosterone in animals, causing chemical castration in animals. Therefore, the monitoring of ATZ residue is essential for human health and ecological balance. Herein, a novel dual-signal amplification photofuel cells (PFC) aptasensor was proposed. The presence of a hole mediator and hollow structure enhances the efficiency of electron-hole pair separation and visible light absorption in the photoanode. Additionally, the effect of dye sensitization plays a crucial role in improving the conversion efficiency of photon-to-electrons in the photocathode. The as-prepared aptasensor realized sensitive detection of ATZ, with a board linear range from 1.0 × 10−13 ∼ 1.0 × 10−6 mol L−1 and a low detection limit of 3.3 × 10−14 mol L−1. The reliability of the as-prepared PFC aptasensor was verified by gas chromatography-mass spectrometry (GC-MS). Therefore, the manufactured PFC aptasensor is a prospective detection method for fruit and vegetables safety analysis. [Display omitted] • A novel dual-signal amplification photofuel cells aptasensor was established. • Hole mediator was used as a novel strategy to improve the P max of PFC system. • The hollow structure contributes to enhancing the output performance of CdS. • NiPc sensitized Cu 7 S 4 was developed as a novel photocathode material. • A high initial P max with a signal-off response aptasensor for ATZ detection. [ABSTRACT FROM AUTHOR]

Carbendazim (CBZ) has been widely used in agricultural production to control fruits and vegetables diseases, but it can also destroy the human endocrine system. Therefore, sensitive detection of CBZ has attracted increasing attention worldwide. In this study, Pd nanoparticles (Pd NPs) decorated on CdS microsphere (Pd NPs/CdS) was prepared by the in-situ photoreduced method, and based on the surface plasmon resonance (SPR) effect of noble metal and Schottky junction between Pd nanoparticles (Pd NPs) and CdS microsphere, the photocurrent after introducing Pd NPs is 7.7 times higher than that of bare CdS microsphere. In view of the outstanding photoelectrochemical (PEC) performance of Pd NPs/CdS and the high specificity of the aptamer, the as-fabricated PEC aptasensor for CBZ detection possesses the excellent detection performance including a broad linear ranging from 1.0 × 10−12 to 1.0 × 10−6 mol/L as a low detection limit of 3.3 × 10−13 mol/L (S/N = 3). Furthermore, the PEC aptasensor was used for determination of lettuce samples from actual agricultural products with satisfactory results. • Schottky junction was formed by photoreduction with Xe lamp irradiation for 5 min. • The Schottky junction promoted the separation of photogenerated electron-hole. • SPR effect was used to increase CdS microspheres to capture visible light. • The PEC aptasensor exhibited excellent selectivity and sensitivity for Carbendazim. [ABSTRACT FROM AUTHOR]