Organophosphorus pesticides (OPs) are widely used in agriculture. However, the residue and accumulation of OPs is a threat to food safety and human health. Thus, a sensitive and accurate OPs detection method is still pursued. Here, we utilized electrostatic adsorption to immobilize weak fluorescent AuNCs on the SiO₂ surface, exciting its aggregation-induced emission (AIE) properties and achieving the amplification of the fluorescent signal. Furthermore, a fluorescence-colorimetric sensor based on self-assembled MnO₂-AuNCs-SiO₂ nanocomposites was constructed. Ascorbic acid (AA), the product of sodium l-ascorbyl-2-phosphate (AAP) in the presence of alkaline phosphatase (ALP), can decompose MnO₂ and “turn on” the fluorescence sensor. Moreover, due to the inhibitory effect of OPs on ALP activity, a dual-mode detection method from fluorescence and colorimetry for OPs was developed. The linear range was from 1 μg/L to 50 mg/L with a detection limit of 0.4 μg/L in the fluorescence detection, while the linear range was from 0.1 μg/L to 50 mg/L with a detection limit of 0.09 μg/L in colorimetric analysis. Besides, the in-situ imaging of OPs in fresh vegetables was achieved and a visual semi-quantitative detection of OPs on a test paper was realized. Therefore, the fluorescent biosensor may show a potential value in field detection.

有机磷农药（OPs）被广泛用于农业。但是，OP的残留和积累对食品安全和人类健康构成威胁。因此，仍然追求灵敏且准确的OP检测方法。在这里，我们利用静电吸附将弱荧光AuNCs固定在SiO ₂表面上，激发其聚集诱导发射（AIE）特性并实现了荧光信号的放大。此外，构建了基于自组装MnO ₂ -AuNCs-SiO ₂纳米复合材料的荧光比色传感器。抗坏血酸（AA）是在碱性磷酸酶（ALP）存在下的1-抗坏血酸-2-磷酸钠（AAP）的产物，可以分解MnO ₂并“打开”荧光传感器。此外，由于OP对ALP活性的抑制作用，开发了一种从荧光和比色法对OP进行双模式检测的方法。荧光检测的线性范围为1μg/ L至50 mg / L，检测限为0.4μg/ L，而线性范围为0.1μg/ L至50 mg / L，检测限为0.09μg / L在比色分析中。此外，还对新鲜蔬菜中的OP进行了原位成像，并在试纸上实现了视觉上的OP的半定量检测。因此，荧光生物传感器在现场检测中可能显示出潜在值。