Fluctuations of the number of adsorbed micro/nanoparticles in sensors for measurement of particle concentration in air and liquid environments

Abstract

We present a theoretical model of fluctuation of the number of adsorbed micro/nanoparticles in environmental sensors operating in air and liquids, taking into account the effects of the mass transfer processes of the target particles in a reaction chamber. The presented analysis shows that the transfer processes have a significant influence on the spectrum of fluctuations. The influence is estimated at different values of target particles concentration, functionalization sites density, and adsorption and desorption rates constants.The analysis provides the guidelines for optimization of sensor design and operating conditions in order to decrease the influence of the transport processes, thus decreasing fluctuations and improving the ultimate performance of sensors for particle detection.