Figure 7
Diagnostic performance of micro-FTIR. Area under receiver operating characteristic (AUC) against wavenumber showing those bands with excellent discriminating power (\(AUC > 0.80\), dashed horizontal line) for positive/negative (a) and positive/mix (b) classes. Selected representative curves of receiver operating characteristic (ROC) and corresponding classification box-plot of the intensity of the left-handed helix DNA (Z form) (\(848\,\hbox {cm}^{-1}\), c), \(\beta \)-sheet structure of Amide I of proteins (\(1693\,\hbox {cm}^{-1}\), d), C=O in IgG carbonyl group (1772 and \(1784\,\hbox {cm}^{-1}\) in (e,f), respectively) bands. The horizontal red line is the threshold for classification.
