title: Reproducible E. coli detection based on label-free SERS and mapping.
abstract: The biosensing for rapid detection of bacteria based on surface-enhanced Raman scattering (SERS) has been widely explored for recent years. It is still a challenge to achieve a high sensitive, reproducible label free detection method for bacteria. In this work, a label-free SERS detection method of Escherichia coli based on incubation with silver colloid was reported. Optimized incubation conditions including shaking speed, time and temperature were used to help construct a rapid SERS method for E. coli analysis. It was found that the enhancement of the Raman signal of E. coli could be achieved to 1.8×10(4) cps (counts per second) with high reproducibility. Three strains of E. coli DSM 1116/498/5695 could be successfully discriminated using such SERS method combining discriminant analysis. Finally, the lowest concentration of E. coli at 1×10(5) cell/mL can be detected by SERS mapping. Thus, our detection method offers higher sensitivity and reproducibility compared to previously reported label free simple-mixing methods, opening an avenue for developing various SERS-based biosensor.
authors.affiliation: College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, China.
authors.forename: Danting
authors.initials: D
authors.lastname: Yang
authors.affiliation: Institute of Hydrochemistry and Chair for Analytical Chemistry, Technische Universität München, Munich, Germany; Department of Pharmacy and Guangdong Province Key Laboratory of Pharmacodynamic of Traditional Chinese Medicine & New Drug Research, Jinan University, Guangzhou, China.
authors.forename: Haibo
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Institute of Hydrochemistry and Chair for Analytical Chemistry, Technische Universität München, Munich, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Haisch
authors.affiliation: Institute of Hydrochemistry and Chair for Analytical Chemistry, Technische Universität München, Munich, Germany.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Niessner
authors.affiliation: College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, China. Electronic address: ibeying@zju.edu.cn.
authors.forename: Yibin
authors.initials: Y
authors.lastname: Ying
mesh_terms: D004926:Escherichia coli / Q000737:chemistry / Q000302:isolation & purification*; D057230:Limit of Detection; D015203:Reproducibility of Results; D013059:Spectrum Analysis, Raman / Q000295:instrumentation / Q000379:methods*; D013696:Temperature
keywords: Discriminant analysis; E. coli; Label-free; SERS; Single bacterium cell