Preparation of a new surface-enhanced Raman scattering substrate and its applica-tion to the detection of E.coli
10.7644/j.issn.1674-9960.2015.04.017
- VernacularTitle:一种新型的表面增强拉曼散射基底的制备及其在大肠杆菌BL21检测中的应用
- Author:
Weili CAO
;
Chongwen WANG
;
Huiyun WU
;
Rui XIAO
;
Shengqi WANG
- Publication Type:Journal Article
- Keywords:
E.coli;
silica nanoparticles;
gold core-silver shell;
nanocomposites
- From:
Military Medical Sciences
2015;(4):306-310
- CountryChina
- Language:Chinese
-
Abstract:
Objective To develop a new type of Raman-enhanced substrate for rapid detection of E.coli based on label-free surface-enhanced Raman scattering( SERS) technology.Methods Stober’ s improved method was used to prepare 360 nm silica ( SiO2 ) nanospheres.Prepared gold core-silver shell nanoparticles( Au@Ag) of different size were attached to 360 nm SiO2 to fabricate the nanocomposites ( SiO2-Au@Ag ) that were characterized by transmission electron microscopy (TEM) and UV-visucl light adsorption spectra (UV-Vis).PATP was detected to select SiO2-Au@Ag with optimal SERS effect.This optimal SiO2-Au@Ag was used to obtain the sensitivity of PATP and E.coli detection after a simple mixed culti-vation.Results TEM images showed that Au@Ag aggregated with the size of Au@Ag attached to 360 nm SiO2 .UV-Vis spectra indicated that the maximum absorption of Au@Ag and SiO2-Au@Ag had a red shift with the invrease of Au@Ag size.The experiment results suggested that detection sensitivity of PATP by SiO2-100 nm Au@Ag 10 -10 mol/L, while the lowest detectable E.coli concentration was 105 CFU/ml.Conclusion The 360 nm SiO2 binding with 100nm Au@Ag exhibits great potential for SERS applications.
