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Journal of Nanotechnology
Volume 2012 (2012), Article ID 297560, 7 pages
http://dx.doi.org/10.1155/2012/297560
Research Article

Surface-Enhanced Raman Scattering of Bacteria in Microwells Constructed from Silver Nanoparticles

1Genetics and Bioengineering Department, Faculty of Engineering and Architecture, Yeditepe University, Istanbul 34755, Turkey
2Acıbadem University, School of Medicine, Department of Infectious Diseases, Büyükdere Cad. No. 40, Maslak, Istanbul 34457, Turkey

Received 2 February 2012; Revised 19 April 2012; Accepted 1 May 2012

Academic Editor: Nickolay Lavrik

Copyright © 2012 Mustafa Çulha et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Whole bacterial cell characterization is critically important for fast bacterial identification. Surface-enhanced Raman scattering (SERS) is proven to be powerful technique to serve such a goal. In this study, the characterization of whole bacterial cells in the microwells constructed from colloidal silver nanoparticles (AgNPs) with “convective-assembly” method is reported. The proper size of the microwells for the model bacteria, Escherichia coli and Staphylococcus cohnii, is determined to be 1.2 μm from their electron microscopy images. A minimum dilution factor of 20 is necessary for the bacterial samples collected from growth media to diminish the bacterial aggregation to place the bacterial cells into the microwells. The constructed microwell structures are tested for their bacterial SERS performance and compared to the SERS spectra obtained from the samples prepared with a simple mixing of bacteria and AgNPs for the same bacteria. The results indicate that microwell structures not only improve the spectral quality but also increase the reproducibility of the SERS spectra.