Study of a portable and highly sensitive glucose Raman detector based on light-guiding metal capillaries

Detection of glucose content is widely demanded in the fields of medicine, food industry and environmental protection. Raman spectroscopy is one of the ideal methods for detecting trace glucose due to its advantages of non-contact, non-destructive, high sensitivity and high selectivity. However, existing Raman spectrometers are difficult to combine high sensitivity, small size and low cost. In this paper, a portable glucose Raman detector with high sensitivity and calibration function was developed using a light-guiding metal capillary (MC). The instrument consists of a laser diode (LD), MC, filter set and photodetector, which can effectively suppress the background noise and adjust the wavelength of the LD through the refrigeration module to realize the wavelength matching between the Raman signal and the narrow bandpass filter. The detection of glucose solution with the concentration of mass fraction 0.01%~10% can realize the detection limit of 0.01%, the signal-to-noise ratio is 9.75, and the linear correlation coefficient is 0.9983. The instrument has the features of small size, high sensitivity, low cost, and is suitable for wide promotion and application.