Huanshun Yin

In this study, a novel triple‐mode biosensor based on a Cu‐N ₄ single‐atom nanozyme (Cu‐N ₄ SAzyme) and an In ₂ O ₃ /Bi ₂₄ O ₃₁ Br ₁₀ Z ‐Scheme heterojunction was constructed for the highly sensitive detection and photocatalytic inactivation of Vibrio alginolyticus ( V. alginolyticus ). The Cu‐N ₄ SAzyme, possessing both ascorbate oxidase‐like and laccase‐like activities, was integrated with nucleic acid isothermal amplification technology. This integration enabled triple‐mode detection via photoelectrochemical (PEC), organic photoelectrochemical transistor biosensor (OPECT), and colorimetric (CL) methods, achieving a limit of detection (LOD, calculated) as low as 1.07 CFU/mL. An In ₂ O ₃ /Bi ₂₄ O ₃₁ Br ₁₀ Z ‐Scheme heterojunction was fabricated as a photoactive gate electrode. Through UV‐vis diffuse reflectance spectrum ‐, Mott–Schottky, and electron spin resonance analyses, we conclude that the electron transfer mechanism is consistent with the proposed Z‐scheme mechanism, demonstrating that this structure exhibits highly efficient space charge separation and long carrier lifetime. Consequently, the photocurrent response was significantly enhanced, enabling highly sensitive triplex biosensing. Concurrently, the In ₂ O ₃ /Bi ₂₄ O ₃₁ Br ₁₀ heterojunction was demonstrated to generate reactive oxygen species (ROS) under light irradiation, enabling the inactivation of a high concentration of V. alginolyticus (approximately 10 ^7.24 CFU/mL) within 3 h. This platform provides an integrated new strategy for both pathogen detection and disinfection.

An organic photoelectrochemical transistor (OPECT) biosensor featuring a Bi4O5I2/Bi2S3 type-II heterojunction gate and Ce/Zr-MOF signal amplification unit was developed for RNA demethylase ALKBH5 with photoelectrochemical (PEC), OPECT, and colorimetric analysis. ALKBH5 catalysis demethylation of RNA was utilized to induce the inhibition on ascorbic acid (AA) generation through dehydroascorbic acid reduction by tris(2-carboxyethyl)phosphine and l-ascorbic acid 2-phosphate hydrolysis by Ce/Zr-MOF catalysis, where AA acted as the bifunctional roles to trigger an increased detection signal with reductant agent to engineer the oxygen vacancy of Bi4O5I2 and electron donor to capture photogenerated holes. The biosensor achieved sensitive PEC and OPECT detection based on the intrinsic signal amplification induced by the organic photoelectrochemical transistor itself as well as the extrinsic signal amplification derived from the heterojunction structure and bifunctional AA. Moreover, based on the Ce/Zr-MOF bifunctional nanozyme with phosphatase-mimetic activity toward PNPP and oxidase-mimetic activity toward TMB, ALKBH5 detection using colorimetry was also realized by PNPP hydrolysis and TMB oxidation to generate yellow and blue, respectively. The biosensor was further applied to evaluate the effect of phthalate plasticizers on the ALKBH5 activity. This work not only provides a versatile multimodal detection technology for ALKBH5 but also offers an approach for evaluating the toxicological effects of pollutants using ALKBH5 as a biomarker.

As an important strategy to modulate electronic structure and carrier behavior, oxygen vacancy (OV) is important for modifying semiconductor materials to removal drug‐resistant bacteria. Herein, Bi ₄ O ₅ Br ₂ with abundant oxygen vacancies (OVs) (Bi ₄ O ₅ Br ₂ ‐OVs) were prepared by room temperature reduction method using L ‐ascorbic acid (AA) as a reducing agent. Controlled generation of ·OH radicals from the nanomaterial enabled highly efficient removal of methicillin‐resistant Staphylococcus aureus (MRSA). The relationship between AA concentration/time and OV concentration was explored. The effect of OV content on the energy band structure was clarified. The equilibrium concentration of OV that can most substantially enhance the photocatalytic performance was evaluated. Under the optimal conditions with 0.15 M AA and 60 min reaction time, Bi ₄ O ₅ Br ₂ ‐OVs possessed the most suitable oxygen vacancy concentration. The removal concentration of MRSA reached 10 ^7.11 CFU⋅mL ⁻¹ within 180 min. In addition, ·OH and h ⁺ were explored as the main active species components by ESR experiments. It was also determined by free radical quantification experiments that the concentration of ·OH produced by Bi ₄ O ₅ Br ₂ ‐OVs was four times more than that by bare Bi ₄ O ₅ Br ₂ . Bi ₄ O ₅ Br ₂ ‐OVs also showed excellent removal rates for antibiotics and antibiotic resistance genes. Moreover, the photocatalysts presented excellent bactericidal ability in the chicken manure water environment. Besides, it also showed high removal rate of MRSA under real sunlight irradiation. Overall, the introduction of oxygen vacancies by room‐temperature reduction improved the photocatalytic performance of Bi ₄ O ₅ Br ₂ , which provided a promising application value for the remediation of drug‐resistant bacterial contamination in aqueous environments.

To effectively control the contamination of antibiotic‐resistant bacteria (ARB) and antibiotic‐resistant genes (ARGs), (Bi, Ni)‐based bimetallic metal‐organic framework (MOF) with Z‐scheme heterojunction was constructed. The visible light‐driven (Bi, Ni)‐bimetallic MOF generated H ₂ O ₂ and other reactive oxygen species, efficiently eliminating 7.22 log antibiotic‐resistant Escherichia coli and 7.16 log methicillin‐resistant Staphylococcus aureus within 60 min. (Bi, Ni)‐bimetallic MOF exhibited strong chemisorption via amino and benzene ring structures, synergistically enhancing the elimination of ARGs. The sterilization mechanism of (Bi, Ni)‐bimetallic MOF was analyzed and discussed based on the results, such as energy band structure and work function. The constructed small reaction equipment was used to explore the potential applications of (Bi, Ni)‐bimetallic MOF, and it demonstrated excellent antibacterial properties under actual sunlight. And the prepared CS‐PVA‐(Bi, Ni)‐MOF film had an outstanding fruit preservation effect. This work provided a reliable idea for controlling contamination of ARB and ARGs.

A Bi ₄ O ₅ I ₂ /BiOBr Z‐Scheme heterojunction‐gated organic photoelectrochemical transistor (OPECT) biosensor is developed for ultrasensitive detection of N ⁶ ‐methyladenosine (m ⁶ A). Catalyzed by the FTO protein, m ⁶ A in RNA is oxidized to be N ⁶ ‐hydroxymethyladenosine (hm ⁶ A), and this RNA sequence is then hydrolyzed by RNase A to generate N ⁶ ‐hydroxymethyladenosine monophosphate (hm ⁶ AMP), which is further captured on the gate by hexakis‐(6‐mercapto‐6‐deoxy)‐α‐cyclodextrin based on the covalent reaction between ─CH ₂ OH and ─SH. Subsequently, Zr‐MOF is immobilized through coordination between the phosphate group of hm ⁶ AMP and Zr ⁴⁺ . Leveraging its phosphatase‐like activity, Zr‐MOF catalyzes the hydrolysis of Na ₃ SPO ₃ to generate H ₂ S, which in situ reacts with Bi ₄ O ₅ I ₂ /BiOBr gate to form double‐II heterojunction of Bi ₂ S ₃ /Bi ₄ O ₅ I ₂ /BiOBr gate, enabling photocurrent polarity inversion and better adapting to depletion transistors employing PEDOT:PSS as the organic semiconductor layer. Concurrently, Zr‐MOF catalyzes the conversion of colorless p ‐nitrophenyl phosphate to yellow p ‐nitrophenol, achieving the colorimetric (CL) detection of m ⁶ A‐RNA. Most importantly, the prepared novel OPECT‐PEC‐CL three‐mode biosensor has excellent selectivity and high sensitivity for m ⁶ A detection with detection limits as low as 3 f m , 0.15 p m, and 0.24 n m , respectively. Additionally, this study explores the effects of plasticizers and microplastic contaminants on root and leaf growth and m ⁶ A levels in rice seedlings.

Mycotoxins and marine biotoxins are highly toxic metabolites produced by fungi and phytoplankton, respectively. They can enter the body of humans and animals through feed or food, causing acute or chronic toxicity on the endocrine and nervous systems, which eventually pose a serious threat to humans and animals' life. Development of inexpensive, fast, specific, and sensitive analytical methods for mycotoxin and marine biotoxin detection in foodstuffs and the environment is of great importance. Owing to the advantages of simple operation, inexpensive and small-sized instrument, high detection sensitivity and selectivity, ease in achieving intelligence, and real-time detection, photoelectrochemical sensors have been applied to detect these toxins. This review summarized the application of photoelectrochemical sensors for mycotoxin and marine biotoxin detection in recent years, especially the recognition approaches for mycotoxins and marine biotoxins and the signal amplification strategies for photoelectrochemical sensors. Ultimately, the current challenges and prospects in this field were also discussed.