荧光探针自组装膜对久效磷农药的检测

Determination of Monocrotophos Based on Self-Assembled Multilayer Films with Fluorescent Probes

采用CdSe量子点作为荧光探针,将巯基丙酸稳定的CdSe、聚二烯丙基二甲基氯化铵(PDDA)和乙酰胆碱酯酶(ACHE)通过静电吸引法,层层组装到石英表面,构建一种荧光性自组装多层膜Quartz/PDDA/CdSe/PDDA/ACHE/PDDA.利用有机磷农药对乙酰胆碱酯酶的抑制机理,成功地将自组装膜用于痕量久效磷农药的检测.实验表明,在乙酰胆碱酯酶被抑制16 min,底物乙酰胆碱浓度为8.8 mmol.L-1的条件下,该膜对久效磷的检测限低至48.64 nmol.L-1.所构建的自组装膜稳定性较好、灵敏度较高,可以再生使用.

A fluorescent self-assembled muhilayer films （Quartz/PDDA/CdSe/PDDA/ACHE/PDDA） was constructed by putting3-mercaptopropionic acid modified CdSe quantum dots （QDs）, PDDA and acetylcholinesterase （ACHE） onto the quartz substrate alternately with the layer by layer assembly technique. And CdSe QDs on the films was used as fluo- rescent probes. By the enzymatic inhibition, the self-assembled multilayer films could be used to detect trace organophos- phorus pesticides successfully. This method was used to detect monocrotophos as low as 48. 64 nmol · L 1 under the operate conditions that, inhibition time was 16 minutes, substrate concentration was 8. 8 nmol · L-1 and the pH of substrate solution was about 9.0. The as-prepared muhilayer films exhibited good regeneration, stability, and high sensitivi- ty.