[Research on glucose measuring technique by surface plasmon resonance based on thiol coupling].

In the glucose measuring technique by surface plasmon resonance, D-galactose/D-glucose binding protein (GGBP) that can specifically adsorb glucose was introduced, and high-precision specific detection of glucose concentration was realized. In the present paper, the GGBP protein was bound on the surface of SPR sensor through thiol coupling method. GGBP binding experiment was carried out on SPR sensor and then glucose concentration experiment was conducted with this sensor. The results indicated that the SPR sensor had good linearity, stability and repeatability in the range of 0.1-10 mg x dL(-1). SPR sensor bound with GGBP would have great potential and vast development prospects.

[Study on detection methods of interstitial fluid glucose concentration based on infrared attenuated total reflection].

Measuring the glucose concentrations in the interstitial fluid is currently the main method to achieve the continuous blood glucose monitoring. The MIR-ATR(Mid-infrared, Attenuated Total Reflection)Spectroscopy has prominent advantage on the analysis of small biological molecule for composition information like the glucose, but it is still an unresolved problem that how to detect the subcutaneous glucose concentration by using the MIR-ATR Spectroscopy. In the present paper, we carry out the experiment based on MIR-ATR for the detection of subcutaneous glucose information on both the natural state and the penetration state based on the theoryanalysis of MIR penetration depth. Firstly, collect spectral data of the subcutaneous glucose concentration of human finger on the natural state were collected as the light shined the skin directly, and it was discussed whether the MIR can penetrate the skin to get the information of subcutaneous glucose. On this basis, collect spectral data of the subcutaneous glucose concentration of human finger at the penetration state were collected when the Interstitial fluid is permeated to the surface layer by using low-frequency ultrasound and vacuum, then it analyzed that whether it can detect the glucose-specific information or not. As the two-dimensional correlation spectroscopy has high resolution and good versatility, it is widely used to analyze the inter-molecular reaction and judge the absorption peaks information in many fields including the MIR spectroscopy field, so we choose the Two-dimensional correlation spectroscopy to analyze the information of subcutaneous glucose concentration at the natural state and the penetration state. The experiment result shows that the MIR-ATR spectroscopy can't be applied in the detection of subcutaneous glucose concentrationdirectly, and it is a promising direction to make the Interstitial fluid permeated to the surface layer by the physical methods or chemical methods.

[Effect of borate polymer layers on measurement of glucose concentration by SPR].

A new borate polymer PAA-ran-PAAPBA that can specifically adsorb glucose was introduced in the glucose measurement based on surface plasmon resonance, and the high-precision specific detection of glucose concentration was realized. Six layers and twelve layers of borate polymer were respectively bound onto the SPR sensors through the layer-by-layer self-assembly binding method, and the effect of different layers of borate polymer on the glucose surface plasmon resonance measurement was studied. The experiment was conducted in the concentration range of 1-10 mg x dL(-1) (interval delta = 1 mg x dL(-1)), 10-100 mg x dL(-1) (interval delta = 10 mg x dL(-1)), and 100-1 000 mg x dL(-1) (interval delta = 100 mg x dL(-1)), experiment data was fitted by quadric curve and the fitting degree of refractive index difference deltaRU and glucose concentration was obtained. Results showed that the 12-layer-polymer sensor was better than the 6-layer-polymer sensor in the first two smaller ranges, and the measuring result was not significantly affected by layers in the third range, indicating that for the small concentrations increasing polymer layer can dramatically improve the measurement.

[Application of mid-infrared wavelength tunable laser in glucose determination].

The authors proposed a method of control and stabilization for laser emission wavelengths and power, and presented the mid-infrared wavelength tunable laser with broad emission spectrum band of 9.19-9.77 microm, half wave width of 4 cm(-1), spectral resolution of 2.7 x 10(4) and max power of 800 mW with fluctuation < 0.8% in the present paper. The tunable laser was employed as the light source in combination with ATR sensor for glucose measurement in PBS solution. In our experiments, absorbance at the five laser emission wavelengths, including 1 081, 1 076, 1 051, 1 041 and 1 037 cm(-1) in the 9R and 9P band of the laser emission spectrum, all correlates well with the glucose concentration (R2 > 0.99, SD < 0.0004, P < 0.000 1). Especially, the sensitivity of this laser spectroscopy system is about 4 times as high as that of traditional FTIR spectrometer.