核壳式Ag@MIPs的制备及对氨苄西林的表面增强拉曼光谱检测

Preparation of Core-shell Ag@MIPs and Its Application for Detection of Ampicillin by Surface-Enhanced Raman Spectroscopy

本文以氨苄西林(AMP)为模板分子,3-(异丁烯酰氧)丙基三甲氧基硅烷(MPS)为硅烷化试剂,甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,2,2-偶氮二异丁腈(AIBN)为引发剂,在Ag微球表面制备了AMP分子印迹聚合物(Ag@MIPs)。采用不同方法对所制备的Ag@MIPs进行了表征。结果表明,Ag@MIPs为粒径较为均一的核壳式结构。以Ag@MIPs作为基底,采用激光共聚焦拉曼光谱仪(激发波长为638nm)对AMP进行检测,结果显示Ag@MIPs基底具有较强的表面增强拉曼光谱(SERS)效果,增强因子可达3.79×105。对AMP浓度和SERS特征峰强度作线性拟合,发现其具有较好的线性关系,相关系数R2为0.959;对AMP检测限达到1.0×10-8 mol/L。竞争吸附实验结果表明Ag@MIPs对AMP具有较高的选择性。方法可用于AMP的快速、灵敏和选择性检测。

Molecularly imprinted polymers(MIPs)were prepared with ampicillin(AMP)used as a template molecule,2,3-ctrimethoxysilyl,propyl methacrylate(MPS)as a silanylation reagents,methacrylic acid(MAA)as a functional monomer,ethyleneglycol dimethacrylate(EGDMA)as a cross-linking and 5,2,2-azobis(2-methylqrogioniztrile(AIBN)as an initiator.AMP was prepared on the surface of silver microspheres.The energy dispersive spectrometry(EDS)and infrared(IR)spectroscopy showed that AMP molecularly imprinted polymers(Ag@MIPs)were successfully prepared on the silver microspheres.X-ray diffraction(XRD)showed that the crystal shape of Ag microspheres did not change after coating MIPs.Scanning electron microscope(SEM)and transmission electron microscope(TEM)showed that the Ag@MIPs microspheres were the core-shell structures with uniform particle size.Using Ag@MIPs microspheres as substrate,the AMP solution was detected by laser confocal Raman spectrometry(excitation wavelength of 638 nm).The results showed that Ag@MIPs had strong Surfaceenhanced Raman scatting(SERS)effect,the enhancement factor reached 3.79×105,and the detection limit of AMP was 1.0×10-8 mol/L.The linear fitting of the strength of AMP and Raman spectra showed a good linear relationship with R2=0.959.The competitive adsorption results of Ag@MIPs showed that Ag@MIPs had high selectivity to AMP.The results of these studies can be used for the rapid,sensitive and selective detection of AMP.