Photonic crystal fiber-based plasmonic sensor with ITO for medical applications

In this paper, a photonic crystal fiber sensor is proposed for urine analysis of diabetic patients. Indium tin oxide (ITO) is adopted as plasmonic material to be coated on the polished plane to ensure a high flatness of the coating. The sensor is immersed in the liquid analyte for detection. Since the refractive index of the abnormal analyte is different from that of the normal level analyte, the change of its refractive index can be determined by comparing and analyzing the shifts of confinement loss peak shift. Simulation results show that the maximum wavelength sensitivity and resolution are 25,000 nm/RIU and 4 × 10 −6 RIU in the refractive index detection range of 1.320–1.355. In addition, the sensor proposed in this paper can change the detection range and sensitivity by changing the thickness of ITO film, which means the thickness of ITO film can be optimized according to the application requirements to achieve customized PCF sensor. To sum up, the sensor proposed in this paper has potential applications in medical and chemical fields. Graphical abstract