Detecting Variable Resistance by Fluorescence Intensity Ratio Technology

We report a new method for detecting variable resistance during short time intervals by using an optical method. A novel variable-resistance sensor composed of up-conversion nanoparticles (NaYF(4):Yb(3+),Er(3+)) and reduced graphene oxide (RGO) is designed based on characteristics of a negative temperature coefficient (NTC) resistive element. The fluorescence intensity ratio (FIR) technology based on green and red emissions is used to detect variable resistance. Combining the Boltzmann distributing law with Steinhart–Hart equation, the FIR and relative sensitivity S(R) as a function of resistance can be defined. The maximum value of S(R) is 1.039 × 10(−3)/Ω. This work reports a new method for measuring variable resistance based on the experimental data from fluorescence spectrum.