Signal-to-Noise Ratio in Adsorption-Based Microfluidic Bio/Chemical Sensors

The noise due to stochastic fluctuations of the number of adsorbed analyte particles, caused by random adsorption-desorption (AD) process coupled with analyte convection and diffusion, is inherent to adsorption-based bio/chemical sensors. It posses the fundamental limit for the detection of analyte. In this study we perform an analysis of the signal-to-noise ratio (SNR) of microfluidic sensors, taking into account their AD noise. We have shown that mass transfer significantly influences the possibility to achieve the acceptable SNR value. It also influences the minimal detectable concentration and also the time necessary to reach the SNR value that ensures reliable real-time detection and quantification of the analyte