以银纳米棒/氯化银为SERS基底用维多利亚蓝B分子探针检测大肠杆菌

摘要

加入增敏剂AgNO3和NaCl,在银纳米棒(AgNRs)表面吸附了较牢固的AgCl并形成高SERS活性的AgNR/AgCl溶胶基底,维多利亚蓝B(VBB)分子探针在1611 cm-1处有一较强的SERS峰.用VBB做大肠杆菌(EC)的染色剂,使染色的大肠杆菌具备VBB分子探针的SERS特性,即VBB染色大肠杆菌也在1611 cm-1处有一较强的SERS峰.在最优条件下,该SERS峰强与大肠杆菌浓度在5×106～3×109 cfu·mL-1范围内成正比,检出限为2×106 cfu·mL-1,用于水样和饮料中大肠杆菌的分析,具有简便、快速、灵敏等优点.%Using AgNO3 and NaCl as enhnacers,highly SERS active AgNRs/AgCl nanosol substrate were prepared,in which the hydrophobic AgCl molecules formed and absorbed on the AgNRs surface by mens of strong hydrophobic forces between Ag-NRs and AgCl.The Vitoria blue B molecular probes on the surfaces of AgNRs/AgCl displayed a strong SERS paek at 1611 cm-1 .VBB was used to dye the Escherichia coli (E .coli ),which exhibited the SERS proprerty with a Raman peak at 1611 cm-1 .Under the optimal conditions,the SERS intensities were linear to E .coli concentration in the range of 5 ×106 ～3 ×109 cfu·mL-1 ,with a detection of 2×106 cfu·mL-1 .The new SERS method was applied for detection of E .coli in real samples, with features such as simplicity,rapidity and sensitivity.The results were in agreement with that of plate-count method.