Conventional microbiological detection and enumeration methods are time-consuming, labor-intensive, and giving retrospective information. The objectives of the present work are to study the capability of surface enhanced Raman scattering (SERS) to detect Escherichia coli (E. coli) using the presented silver colloidal substrate. The obtained results showed that the adaptive iteratively reweighed Penalized Least Squares (airPLS) algorithm could effectively remove the fluorescent background from original Raman spectra, and Raman characteristic peaks of 558, 682, 726, 1128, 1210 and 1328 cm^-1 could be observed stably in the baseline corrected SERS spectra of all studied bacterial concentrations. The detection limit of SERS could be determined to be as low as 0.73 log CFU/ml for E. coli with the prepared silver colloidal substrate. The quantitative prediction results using the intensity values of characteristic peaks were not good, with the correlation coefficients of calibration set and cross validation set of 0.99 and 0.64, respectively.

Date Published: 13 May 2015
PDF: 7 pages
Proc. SPIE 9488, Sensing for Agriculture and Food Quality and Safety VII, 94880Q (13 May 2015); doi: 10.1117/12.2176826

Published in SPIE Proceedings Vol. 9488:
Sensing for Agriculture and Food Quality and Safety VII
Moon S. Kim; Kuanglin Chao; Bryan A. Chin, Editor(s)