Measurement of Glycated Hemoglobin Through Photoacoustic Spectroscopy: A Non-destructive Assessment

The goal of the study was to measure glycated hemoglobin (HbA1c) by means of photoacoustic spectroscopy (PAS). Absorption spectra from 250  nm to 750 nm were obtained at room temperature from six commercial standards of HbA1c. The sample (60 μL\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mu L$$\end{document}) was confined in a photoacoustic cell. The cell was impinged with a monochromatic light originated in xenon lamp (700 W) and was modulated in a mechanical optical chopper (fixed at 17 Hz). The modulated light heated the sample which releases the heat to the air in the cell, producing changes in pressure that were detected by a microphone and amplified to be recorded as an absorption spectrum. Five measurements were performed in every standard. The area under the curve (auc) of the spectra (250  nm to 750 nm) significantly correlated (p = 0.01) with and was dependent on the standard HbA1c concentration (3.1 % to 19.8 %). As far as we know, it is the first time that PAS has been used to detect HbA1c. It is concluded that PAS, a non-destructive technique, is a suitable technology to measure Hba1c, with the advantages of using small samples that are available for the measurement of other substances by the same technology.