The concentration of glucose in interstitial fluid determined by using the surface plasmon resonance (SPR) biosensor
with chemical bonding D-Galactose/D-Glucose Binding Protein (GGBP) is proposed in this paper.
D-Galactose/D-Glucose Binding Protein (GGBP), a kind of protein which has the ability to absorb the glucose
specifically, is immobilized on the gold film of the SPR sensor to improve the sensitivity of glucose detecting. The
GGBPs mutated at different points have different association abilities with glucose, which bring different measurement
range and precision. So the selection of proteins is a critical problem of the determination of glucose by using SPR
biosensor. Using different mutated GGBPs, the samples with different concentrations of glucose are measured in the
experiment, and the prediction error and precision are discussed. Furthermore, the light intensity of sensor is instable, so
the baseline of SPR responses is tracked and adjusted accordingly using the methods - fixing points and fixing areas'
ratio. The experiment results show that GGBPs mutated at different points have its corresponding working curves and
different measurement precision. In conclusion, the study is significant for the application of SPR biosensor to the
minimally invasive diabetes testing and other detection of human body components.