A high performance differential sensing system based on molecularly imprinted polymer for specific propofol concentration monitoring

In this paper, a high performance differential sensing system combining microfiber interferometer (MFI) and fiber Bragg gratings (FBGs) based on molecularly imprinted polymer (MIP) film is proposed for specific propofol concentration detection. Surface refractive index changes are translated into interference wavelength shift resulting in the change of grating power difference, which helps simplify demodulation equipment. Betacyclodextrin ( beta-CD) assisted MIP film enables optic-fiber system to have specific recognition of propofol. Experimental results show that the sensing system has an obvious response to propofol in the concentration range of 0.001 - 10 mM, and a sensitivity of 6.04 nm/mM and the optimal sensitivity of differential modulation is 10.89 dB/mM in the concentration range of 0.001 - 0.05 mM. The sensing system also has excellent stability and specificity in artificial urine environment. The proposed sensing system not only provides a new method for the determination of propofol concentration, broadens the application field of optical sensor, and provides a new platform for application in biomedicine fields.