分子印迹荧光传感器的研制及其对呋喃妥因的特异性识别

摘要

A novel molecular imprinted polymer(MIP) sensor was successfully prepared for selective direct detection of nitrofurantoin in water and feed samples.To obtain the fluorescent sensor,carbon quantum dots(CDs) were synthesized by using citric acid as carbon source,modified with silane agent to introduce polymerizable bonds on the CDs surface,then a nitrofurantoin molecularly imprinted polymer(MIP) nanofilm was attached on the modified CDs surface.The structure and morphology of CDs and MIP-CDs were characterized by fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM).A series of adsorption experiments were performed to investigate the absorption capacity of MIP-CDs.The results showed that the relationship between fluorescence quenching and nitrofurantoin concentration followed the Stern-Volmer equation with a good linear response in the range of 0-10 mg/L,and the detection limit for nitrofurantoin was 2 μg/L.In addition,the MIP-CDs were employed to detect the nitrofurantoin in water and feed samples with recoveries of 78.0％-95.2％ and RSDs not more than 6.4％ (n =3).The developed method was simple,rapid and selective,and was suitable for the analysis of trace nitrofurantoin in water and feed samples.%采用柠檬酸作为碳源合成了荧光碳量子点(CDs),经硅烷化试剂改性后,以呋喃妥因为模板分子,在其表面合成了分子印迹聚合物(MIP-CDs).以傅立叶变换红外光谱仪(FTIR)和扫描电镜(SEM)对合成产物进行结构和形貌表征;通过一系列吸附实验研究了MIP-CDs对呋喃妥因的识别性能.实验结果表明:在最佳吸附条件下,MIP-CDs的荧光猝灭程度与呋喃妥因的浓度符合Stern-Volmer方程,呋喃妥因在0～10mg/L质量浓度范围内具有良好的线性关系(r2 =0.991 4),方法检出限(S/N=3)为2 μg/L.在水样和饲料样品中添加不同浓度的呋喃妥因,加标回收率为78.0％ ～ 95.2％,相对标准偏差(RSD)不大于6.4％,符合分析方法学要求.该方法简单、快速、选择性好,可直接用于水体和饲料中痕量呋喃妥因的监测.