Abstract Determination of blood glucose level is a frequently occurring procedure in diabetes care. As the most common method involves collecting blood drops for chemical analysis, it is invasive and liable to afflict a degree of pain and cause a skin injury. To eliminate these disadvantages, this thesis focuses on pulsed photoacoustic techniques, which have potential ability in non-invasive blood glucose measurement. The fundamental theory of photoacoustics in liquid and soft tissue was studied systematically. The distributions of photoacoustic sources in a near-infrared optical skin model were simulated by the Monte Carlo method. Expansion coefficient and specific heat of glucose solution were measured by thermodynamic method, while the sound velocity in it was determined by photoacoustic approach. The effect of glucose on blood optical scattering was studied by a picosecond pulsed laser together with a streak camera. A photoacoustic apparatus comprising a pulsed laser diode and a piezoelectric transducer was built and applied to measure glucose concentration in water and scattering media. Moreover, this apparatus was also used to non-invasive experiment on human fingers. The measurements showed that the expansion coefficient, specific heat and acoustic velocity change by 1.2%, -0.6% and 0.28%, respectively, in response to a 1% change in glucose concentration. The sum effect of these parameters to photoacoustic signal was much larger than that of optical absorption of glucose in near infrared wavelengths, which provided photoacoustic technique a higher degree of sensitivity than offered by the optical absorption method. At the wavelength of 905 nm, the measured glucose detection sensitivity in a 3% milk solution, a tissue sample and whole human blood was 5.4%, 2.5% and 14%, respectively. Each figure is higher than that of glucose in water, about 2%, for a one percent change in glucose concentration. This was supported by the temporal dispersion curves of glucose in blood samples, which demonstrated that glucose decreased the optical scattering of tissues. The currently photoacoustic apparatus could detect the minimal glucose concentration of 100 mg/dl in whole blood samples. It is sensitive to physiological changes in non-invasive measurement, but insufficient for evaluating change in the physiological glucose concentration. Current photoacoustic techniques have apparently advantages in study of scattering media and made great progress in tissue imaging and diagnosis. However, in non-invasive blood glucose measurement they met similar problems as optical approaches based on scattering effect.

Electrochemical polymerization of pyrrole functionalized polystyrene (PStPy) with pyrrole was carried out in water-sodium dodecyl sulfate solvent-electrolyte couple. Characterization of the resulting copolymer was performed via Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and four probe conductivity measurements. Glucose oxidase and polyphenol oxidase enzymes were immobilized in polypyrrole (PPy) and conducting copolymer of pyrrole functionalized polystyrene with pyrrole (P(PStPy-co-Py). Resulting enzyme electrodes were characterized by kinetic parameters / Vmax and Km. Behavior of enzyme electrodes upon temperature and pH changes were investigated. Glucose oxidase electrode was used for the determination of glucose in orange juice and polyphenol oxidase electrode was used for the determination of polyphenolic compounds in red wine.