A luminescent probe based on terbium-based metal-organic frameworks for organophosphorus pesticides detection

Terbium-based metal-organic frameworks (Tb-MOF) prepared under mild conditions was utilized to construct a fluorescence probe for determination of organophosphorus pesticides (OPs) coupled with acetylcholinesterase (AChE), acetylcholine chloride (Ach), and choline oxidase (CHO). Since OPs have obvious inhibition on the activity of AChE in the Tb-MOF/ACh/CHO/AChE system, the detection of OPs was accomplished by restoring the fluorescence of Tb-MOF resulting from reduced production of H₂O₂. By taking chlorpyrifos (CPF) as a pesticide model, the method exhibits high sensitivity in the linear range 0.1-4.0 μg·L^-1 with the limit of detection (LOD) of 0.04 μg·L^-1 under optimum conditions (λ_ex = 280 nm, λ_em = 544 nm). The Tb-MOF/ACh/CHO/AChE fluorescence system has high selectivity for CPF. The method was successfully applied to the detection of CPF in tap water and strawberry samples (recovery of 87.36-115.60% for tap water and 95.04-103.20% for strawberry). Free from complicated fabrication operation, the Tb-MOF-based system is rapid, simple, and stable, which provides a reference and new way for the design of OPs fluorescent probes in the future.