Multivariate methodology for surface enhanced Raman chemical imaging of lymphocytes
Artikel i vetenskaplig tidskrift, 2006

Surface enhanced Raman spectroscopy (SERS) was used to study the uptake of rhodamine 6G in human lymphocytes. In total four Raman images of lymphocytes were used. The aim was to find a multivariate methodology capable of separating spectra with chemical information from those that mainly contained the surface enhanced background, in order to create chemical images. The standard PCA procedure was compared with PCA of standard normal variate (SNV) corrected spectra, spectra baseline corrected in the wavelet domain, and variable trimming before PCA, to isolate unique spectra. It was not straightforward to perform a standard PCA for overview, since the small background variation in many variables dominated over the Raman band variation that only occur in few variables. It was shown that wavelet filtering could remove background variations and that variable trimming followed by PCA modelling left the unique Raman spectra as outliers, which facilitated interpretation of the Raman score images.

SNV-transformation wavelets

Raman

variable trimming

multivariate analysis

PCA

Spectroscopy

chemical imaging

SERS

single cells

PLS

Författare

Charlotte Eliasson

Chalmers, Kemi- och bioteknik, Analytisk kemi

Johan Engelbrektsson

Chalmers, Kemi- och bioteknik, Analytisk kemi

Anders Lorén

Chalmers University of Technology

SP Sveriges Tekniska Forskningsinstitut

Jonas Abrahamsson

Göteborgs universitet

Katarina Abrahamsson

Chalmers, Kemi- och bioteknik, Analytisk kemi

Mats Josefson

AstraZeneca AB

Chemometrics and Intelligent Laboratory Systems

0169-7439 (ISSN)

Vol. 81 13-20

Ämneskategorier

Analytisk kemi

Kemi

DOI

10.1016/j.chemolab.2005.06.014