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Vanillin is often used in food and medicine because of its unique flavor and pharmacological effects. However, excessive vanillin intake can harm human health; therefore, rapid and simple vanillin detection methods are required. In this study, porphyrin‐based conjugated microporous polymer‐grafted graphene (CMP‐rGO) was synthesized via the Sonogashira–Hagihara coupling reaction and assembled into an electrochemical sensor for vanillin detection. Due to the enhanced electrical conductivity and electrocatalytic characteristics of CMP‐rGO, the sensor demonstrated a low detection limit of 0.07 μM and a broad response range of 0.08–20 μM. Furthermore, this reusable sensor exhibited acceptable recoveries when evaluating vanillin in pharmaceuticals and human serum. This study offers technological assistance for the rapid detection of vanillin in pharmaceuticals and broadens the application of CMP‐rGO. [ABSTRACT FROM AUTHOR]

Vanillin (Van) is widely utilized in processed foods and medicines for its appealing scent and multiple therapeutic benefits. However, its overconsumption poses a risk to public health, making its quantification essential for ensuring food and medicine safety and quality. This study introduces a stable and conductive phthalocyanine-based porous organic polymer (NiPc-CC POP), synthesized through a straightforward electrophilic substitution of nickel tetra-amine phthalocyanine (NiTAPc) with cyanuric chloride (CC). Appropriate characterization techniques were employed to determine the morphologies and structures of the synthesized materials. Furthermore, the NiPc-CC POP was applied to devise a sensitive Van detection method. Leveraging the high electrocatalytic activity of NiPc-CC POP toward Van oxidation, a linear response of 0.15–32 μmol L−1 was achieved, along with an exceptional detection limit of 0.10 μmol L−1. The sensor demonstrated high selectivity and stability. Samples of human serum and tablets spiked with Van were analyzed, yielding satisfactory recoveries. Consequently, this work contributes to the advancement of sensitive detection platforms for Van at minimal concentrations. [ABSTRACT FROM AUTHOR]

L‐cysteine plays a vital role in organisms, and is an important biomarker for many pathological diseases that seriously affect human health. In the study, a photoelectrochemical (PEC) probe with zinc‐tetramine phthalocyanine covalently grafted to graphene oxide (ZnTAPc‐Gr) was developed for L‐cysteine detection. Graphene oxide (GO) with carboxyl was used to immobilize zinc‐tetramine phthalocyanine (ZnTAPc) with amidogen (a graft structure formed by an amide covalent bond), which could firmly immobilize ZnTAPc, thereby improving the photoelectrochemical performance and stability. L‐cysteine molecule, an electron acceptor, was specifically recognized by the PEC probe, exhibiting a decrease in the photocurrent signal. Under the optimal experimental conditions, the fabricated PEC probe exhibited excellent performance in L‐cysteine analysis within a linear range of 0.25–113 μM and a detection limit of 11.4 nM. The PEC probe showed high sensitivity, selectivity, and stability. The method described herein provides an effective strategy for PEC probe construction for L‐cysteine detection, and can also serve as a promising PEC platform for the analyses of other small molecules. [ABSTRACT FROM AUTHOR]

Designing a simple and sensitive photoelectrochemical (PEC) sensor is crucial to addressing the limitations of routine analytical methods. The sensitivity of the PEC sensor, however, relies on the photoelectric material used. In this manuscript, composites of MoS 2 /rGO (MG) with a large area and layered structure are prepared by simple steps. This material exhibits sensitivity to visible light and demonstrates outstanding photoelectric conversion performance. The constructed PEC aptasensor using this material to detect aflatoxin B1 (AFB1) shows significantly higher sensitivity and stability compared to similar sensors. This may be attributed to the presence of surface defects in MoS 2 , which provide more active sites for photocatalysis. Additionally, graphene oxide (GO) is reduced to rGO by thiourea and forms a heterojunction with MoS 2 , enhancing charge carrier separation and interfacial electron transfer. Our research has revealed that the photocurrent intensity of the aptamer electrode decreases with an increase in AFB1 concentration, resulting in a "signal-off" PEC aptasensor. The detection limit of this aptasensor is 2.18 pg mL -1 , with a linear range of 0.001 to 100 ng mL -1 . This result will also provide a reference for the study of other mycotoxins in food.