Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan, 410005, PR China.
Key Laboratory of Environmentally Friendly Chemistry and Applications of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan, 410005, PR China.
Talanta. 2022 Aug 15;246:123525. doi: 10.1016/j.talanta.2022.123525. Epub 2022 May 6.
Carbaryl is a widely-used carbamate pesticide and the detection of its residues in environmental, food and clinical samples is of great importance. In this sturdy, we developed a green photocatalytic-biosensor based on double strand DNA-SYBR green I complex for sensitively colorimetric detection of carbaryl. This green photocatalytic-biosensor can oxidize 3,3',5,5'-tetramethylbenzidine (TMB) into blue ox-TMB. Meanwhile thiocholine is catalytically produced by acetylcholinesterase (AChE) to directly reduce blue ox-TMB into colorless TMB. But the activity of AChE will be suppressed by carbaryl, thus generating less thiocholine and resulting in more ox-TMB for colorimetric analysis. After the careful optimization of sensing conditions (2 μM for DNA concentration, 50 × concentration for SYBR Green I, 10 min for illumination time), the lowest detectable concentration for carbaryl is 0.008 ng/mL with a linear response in the range of 0.01-0.25 ng/mL. In addition, this photocatalytic-biosensor has good selectivity over non-target chemicals (acetamiprid, atrazine, carbendazim, melamine, bisphenol A, estradiol). It also allows detection of pesticides in real samples verified by a standard HPLC method.
甲萘威是一种广泛使用的氨基甲酸酯类农药，检测其在环境、食品和临床样本中的残留非常重要。在本研究中，我们基于双链 DNA-SYBR 绿 I 复合物开发了一种绿色光催化生物传感器，用于灵敏比色检测甲萘威。这种绿色光催化生物传感器可以将 3,3',5,5'-四甲基联苯胺 (TMB) 氧化成蓝色 ox-TMB。同时，乙酰胆碱酯酶 (AChE) 催化产生硫代胆碱，直接将蓝色 ox-TMB 还原为无色 TMB。但是，甲萘威会抑制 AChE 的活性，从而生成较少的硫代胆碱，导致更多的 ox-TMB 用于比色分析。在仔细优化传感条件（DNA 浓度为 2 μM，SYBR Green I 浓度为 50×，光照时间为 10 分钟）后，甲萘威的最低检测浓度为 0.008 ng/mL，线性响应范围为 0.01-0.25 ng/mL。此外，该光催化生物传感器对非目标化学物质（乙酰甲胺磷、莠去津、多菌灵、三聚氰胺、双酚 A、雌二醇）具有良好的选择性。它还可以通过标准 HPLC 方法验证的实际样本中检测到农药。
