文献类型：期刊文献

英文题名：Multifunctional magnetic-plasmonic nanoparticles for fast concentration and sensitive detection of bacteria using SERS

作者：Zhang, Lei[1];Xu, Jiajie[1,2];Mi, Luo[1];Gong, Heng[2];Jiang, Shaoyi[1];Yu, Qiuming[1]

机构：[1]Univ Washington, Dept Chem Engn, Seattle, WA 98195 USA;[2]E China Univ Sci & Technol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China

年份：2012

卷号：31

期号：1

起止页码：130

外文期刊名：BIOSENSORS & BIOELECTRONICS

收录：;EI(收录号：20115214650807);WOS:【SCI-EXPANDED(收录号:WOS:000300468400021)】；

基金：This work was supported in part by the University of Washington (UW) faculty start-up funds and NOAA Oceans and Human Health Initiative funds (Q.Y.). S.J. acknowledges the support from the Defense Threat Reduction Agency (HDTRA1-10-1-0074). J.J.X. acknowledges the fellowship from the China Scholarship Council. Nanofabrication and SERS measurements were performed at the Nanotech User Facility, the UW site of the National Nanotechnology Infrastructure Network (NNIN) supported by the NSF.

语种：英文

外文关键词：Multifunctional nanoparticles; Magnetic concentration; SERS; Bacteria detection

摘要：Multifunctional magnetic-plasmonic Fe3O4-Au core-shell nanoparticles (Au-MNPs) were prepared for simultaneous fast concentration of bacterial cells by applying an external point magnetic field, and sensitive detection and identification of bacteria using surface-enhanced Raman spectroscopy (SERS). We demonstrated that a spread of a 10 mu L drop of a mixture of 10(5) cfu/mL bacteria and 3 mu g/mL Au-MNPs on a silicon surface can be effectively condensed into a highly compact dot within 5 min by applying an external point magnetic field, resulting in 60 times more concentrated bacteria in the dot area than on the spread area without concentration. Surrounded by dense uniformly packed Au-MNPs, bacteria can be sensitively and reproducibly detected directly using SERS. The principle component analysis (PCA) showed that three different Gram-negative bacterial strains can be clearly differentiated. We also demonstrated that the condensed multifunctional Au-MNPs dot can be used as a highly sensitive SERS-active substrate and a limit of detection better than 0.1 ppb was obtained in detection of small molecules such as 4-mercaptopyrine. This novel platform significantly simplifies the concentration and detection process, which holds great promise for applications in food safety, environmental monitoring, medical diagnoses, and chemical and biological threat detections. (C) 2011 Elsevier B.V. All rights reserved.