Zhang Ruxia, Wang Qi, Fan Zhefeng
School of Chemistry and Materials Science, Shanxi Normal University, Taiyuan, 030031, People's Republic of China.
Department of Chemistry and Chemical Engineering, Taiyuan Institute of Technology, Taiyuan, 030008, People's Republic of China.
Mikrochim Acta. 2025 Apr 21;192(5):309. doi: 10.1007/s00604-025-07151-8.
Malachite green (MG), one of the most toxic veterinary drug residues, is of great significance to establish a rapid, accurate, and highly selective on-site quantitative detection method for food safety. In this study, a new strategy for the detection of MG in aquatic products is developed, which is based on orange fluorescent carbon dots (O-CDs) as nanoswitches for rapid and reversible detection of MG content. The overlap between the strong absorption of MG at 615 nm and the fluorescence emission spectra of O-CDs at 564 nm provides effective support for the internal filter effect (IFE) leading to fluorescence quenching of the system. Under the attack of negative hydrogen ions in NaBH, MG is effectively reduced to weakly absorb leucomalachite green (LMG), blocking the IFE process and leading to the recovery of system fluorescence, thereby achieving reversible detection of MG within 30 s with up to 9 cycles. In solution, the strategy demonstrates a wide linear range of 1-120 μM for MG with a detection limit of 0.37 μM. In addition, a smartphone-assisted O-CDs agar slice sensing platform has been developed, which can accurately quantify and visually determine MG. Furthermore, it is also utilized for fluorescence imaging of exogenous MG in zebrafish. In summary, the establishment of sensing strategy provides a solution for constructing qualitative and visual semi quantitative sensors on site, which has potential application value in food safety assessment.
孔雀石绿（MG）是毒性最强的兽药残留之一，建立一种快速、准确且高选择性的食品安全现场定量检测方法具有重要意义。本研究开发了一种检测水产品中MG的新策略，该策略基于橙色荧光碳点（O-CDs）作为纳米开关，用于快速、可逆地检测MG含量。MG在615 nm处的强吸收与O-CDs在564 nm处的荧光发射光谱之间的重叠，为导致系统荧光猝灭的内滤效应（IFE）提供了有效支持。在NaBH中负离子的作用下，MG被有效还原为弱吸收的隐色孔雀石绿（LMG），阻断了IFE过程，导致系统荧光恢复，从而在30 s内实现MG的可逆检测，循环次数高达9次。在溶液中，该策略对MG的线性范围为1-120 μM，检测限为0.37 μM。此外，还开发了一种智能手机辅助的O-CDs琼脂片传感平台，该平台可以准确地定量并直观地测定MG。此外，它还用于斑马鱼中外源MG的荧光成像。综上所述，该传感策略的建立为现场构建定性和可视化半定量传感器提供了解决方案，在食品安全评估中具有潜在的应用价值。
