Measurement of Low Concentrations of Nanoparticles in Aerosols Using Optical Dielectric Microcavity: The Case of TiO 2 Nanoparticles

A method for measuring low concentrations (up to 0.001 mg/mL) of TiO2 nanoparticles in aerosols using an optical dielectric microcavity is proposed. The method is based on measuring the change in the microcavity Q factor due to the adsorption of particles on its surface. The results of experimental studies of aerosol samples containing TiO2 nanoparticles with a diameter of 40 nm with different concentrations are presented. The method for calibrating the measurement channel is developed. The basic requirements for the optical dielectric microcavity as a primary measuring transducer are formulated. The influence of the opticalmode volume on the measurement error is estimated.