分子印迹光子晶体凝胶传感器检测食品中的防腐剂

将响应性光子晶体与分子印迹技术相结合,建立了一种反蛋白石结构的分子印迹光子晶体凝胶传感器,并成功用于水果罐头中痕量防腐剂尼泊金乙酯的筛查。该传感器对尼泊金乙酯具有良好的识别能力,抗干扰能力强,对待测物的识别过程可通过光纤光谱仪转化成可读的光学信号,其布拉格衍射峰位移值与尼泊金乙酯浓度呈线性相关,定量下限为83 mg/L,且可重复使用。该检测平台具有便携式特征,无需对样品进行前处理,可准确、灵敏、快捷地检测复杂样品中的目标分析物,适于现场快速筛查和检测。

Determination of Preservatives in Food Using a Molecularly Imprinted Photonic Crystal Gel Sensor

An inverse opal structural molecular imprinted photonic crystal (MIPC) sensor was established by combining the responsive photonic crystal and molecular imprinting techniques.The 3-D opal structure was obtained by vertical deposition self-assembly of monodisperse silica nanospheres which were prepared by St~ber method.MIPC was obtained after removing SiO2 nanospheres and imprinted molecules.Scanning electron microscope showed that the MIPC possessed a highly ordered 3 -D macroporous structure.The recognition for target analytes could be directly transferred into readable optical signals through a fiber optic spectrometer.The factors,such as eluate,pH value,sample matrix and molecular imprinted polymer(MIP) synthesis conditions,were optimized to improve the recognition ability and sensing properties of MIPC sensor.The MIPC sensor showed a good selectivity to ethyl paraben against interferons (2-hydroxy isobutyric acid,benzocaine and procaine) studied.Under the optimized conditions,the shift value of Bragg Diffraction peak of MIPC sensor was linearly related with the concentration of ethyl paraben.The sensor could be re-used with well performance,and the quantitation limit is 83 mg/L.The MIPC sensor could be applied directly and conveniently in monitoring of the target analytes in complex samples with good accuracy and sensitivity,and there is no need for sample processing.So it is suitable for on-site rapid screening and detection.