Key Laboratory for Bio based Materials and Energy of Ministry of Education, College of Materials and Energy, South China Agricultural University, Guangzhou 510642, China; The Guangdong Provincial Key Laboratory of Food Quality and Safety, College of Food Science, South China Agricultural University, Guangzhou 510642, China.
Key Laboratory for Bio based Materials and Energy of Ministry of Education, College of Materials and Energy, South China Agricultural University, Guangzhou 510642, China.
J Hazard Mater. 2021 Jun 5;411:125090. doi: 10.1016/j.jhazmat.2021.125090. Epub 2021 Jan 8.
The convenient and effective detection of toxins is urgently demanded for food security and human health. Herein, based on the catalytic activity of mimetic peroxidase from the CuO@Fe(OH) yolk-shell nanocages, a dual-modal multi-colorimetric and ratiometric fluorescence immunosensor for the sensitive detection of ochratoxin A (OTA) was successfully developed. For the multi-colorimetric detection, HO can be effectively decomposed by CuO@Fe(OH) to form ·OH groups, thus Au nanorods (Au NRs) can be etched to exhibit vivid color variations and localized surface plasmon resonance (LSPR) shifts. For the ratiometric fluorescence detection, o-phenylenediamine was oxidized by CuO@Fe(OH) to form 2,3-diaminophenazine (DAP) in the presence of HO. Interestingly, the exogenous fluorescence signal source of carbon dots can be quenched by DAP via inner filter effect, while a new emission peak at 563 nm can be discovered, forming a ratiometric fluorescence signal. Due to the independent signals and mutual confirmation, the performance of the dual-modal immunosensor for the detection of OTA was significantly improved, where a broad linear range from 1 ng/L to 10 μg/L with a detection limit of 0.56 ng/L (S/N = 3) was achieved. The sensing strategy was also used to monitor OTA in millet and lake water samples with a satisfied performance.
食品安全和人类健康迫切需要方便有效的毒素检测方法。在此基础上，基于 CuO@Fe(OH) 蛋黄壳纳米笼的模拟过氧化物酶的催化活性，成功开发了用于灵敏检测黄曲霉毒素 A (OTA)的双模态多色比色和比率荧光免疫传感器。对于多色检测，HO 可被 CuO@Fe(OH) 有效分解生成·OH 基团，从而可刻蚀 Au 纳米棒 (Au NRs) 以显示生动的颜色变化和局域表面等离子体共振 (LSPR) 位移。对于比率荧光检测，在 HO 的存在下，邻苯二胺被 CuO@Fe(OH) 氧化形成 2,3-二氨基吩嗪 (DAP)。有趣的是，通过内滤效应，碳点的外源荧光信号源可被 DAP 猝灭，同时可发现新的发射峰在 563nm 处，形成比率荧光信号。由于独立信号和相互验证，双模态免疫传感器用于检测 OTA 的性能得到了显著提高，其线性范围从 1ng/L 到 10μg/L，检测限为 0.56ng/L（S/N=3）。该传感策略还用于监测小米和湖水样品中的 OTA，具有令人满意的性能。
