Highly sensitive PCF-SPR biosensor for hyperthermia temperature monitoring

A highly sensitive photonic crystal fiber based on a surface plasmon resonance (PCF-SPR) biosensor is designed for local temperature detection in brain tumor treatment. In order to obtain high sensitivity, the mixture of chloroform and toluene whose refractive index is temperature sensitive and is injected into the analyte channel coated with a thin gold layer. The temperature sensing performance and coupling properties of the PCF-SPR biosensor are numerically simulated by the finite-element method. By means of the wavelength interrogation method, a maximum temperature sensitivity of − 6000 pm/°C is achieved for the temperature sensing range between − 50 °C and 100 °C, corresponding to a resolution of the PCF-SPR temperature biosensor as low as 0.017 °C. The temperature sensitivity is the largest among the reported PCF-SPR sensors, to the best of our knowledge. Owing to the high sensitivity and resolution, the proposed biosensor has the potential to be used for hyperthermia monitoring in brain tumor treatment.