Behavior of long-period measurements using a small-sized photoacoustic cell for aqueous glucose monitoring

Reliable, noninvasive glucose-monitoring devices are not currently available. From the patient´s point of view, it is necessary that glucose-monitoring devices are portable as well as noninvasive. In photoacoustic spectroscopy (PAS), the PA signal induced by the irradiation of the sample with modulated light depends on the optical absorption coefficient of the sample. Unlike the sensitivity of conventional absorption spectroscopy, the sensitivity of PAS scales inversely with the dimensions. An external laser (wavelength of 1550 nm) and a PA cell with a volume of only 4.0 mm³ were used for monitoring a glucose solution contained in a special sample reservoir. We present PA measurements of glucose in aqueous solutions using a sample reservoir that is suitable for investigations of liquid samples, such as native capillary blood, by performing a long-period measurement.