Metal-printing directly defined polymer optical waveguide sensors for detecting effective anti-inflammatory concentrations of peimine as fritillaria alkaloid drugs

Abstract

Novel polymer optical sensors for detecting effective anti-inflammatory concentrations of peimine as fritillaria alkaloid drugs are successfully designed and fabricated by the metal-printing directly defined active waveguide technique. The erbium-containing cross-linked copolymer and the organic–inorganic grafting PMMA material are used as a sensing core layer and cladding window, respectively. Multi-hydrogen-bonding affinity interactions between the tested drug and the sensing polymer layer are analyzed by the molecular docking model. The multimode interference (MMI) waveguide sensor structure is optimized to design. The sensitivity included of the bulk and surface parts for the waveguide optical sensor is analyzed. The optical transmission field of the device is simulated based on the refractive indices of different peimine concentrations. The sensitivity of the device is measured as 2 × 103 RIU−1. The resolution and detection limit of the sensor are characterized to be 2.5 × 10−4 and 1.3 × 10−7 RIU, respectively. The effective anti-inflammatory concentration range (10-25 mg/L) of the peimine solution could be efficiently detected in the scope of 5 dB corresponding to the maximum output optical power change. Relative optical gain of the chip is obtained as 3 dB for achieving calibration of the sensor. The technique could realize a simple, rapid and controlled process with high sensitivity for detecting effective anti-inflammatory concentration of alkaloid drugs in traditional Chinese medicine.