Real-Time FET-Based Biosensor Using the Wet Cyclone Air Sampler

Traditionally, microbial pollution of the environment has been associated with missions from operations in agricultural farms, poultry processing plants, landfills, and waste processing facilities. With the advent of biotechnology, new sources of bio-aerosol pollution have been generated from the utilization of genetically-engineered microbial strains in producing pharmaceuticals, enzymes, and food substitutes. Thus, detection of airborne pollution particles such as pathogenic, allergenic, and microorganisms is crucial to ensure a sanitary work environment. In this study, a cyclone bio-aerosol sampler is designed based on the Stokes number and Reynolds number to collect and concentrate bio-aerosol particles in a liquid. In addition, computational fluid dynamics (CFD) techniques are used to study the performance of an bio-aerosol sampling cyclone that continuously collects particles onto a flowing liquid film. At an aerosol sampling flow rate of 1000 L/min and a continuous liquid outflow rate of 1 mL/min, Cutpoint particle size is about 1 μm aerodynamic diameter. The sampler was connected to the FET-based biosensor using fluid channel in order to design real-time detection system (fig. 1). To evaluate the real-time detection system, protein particles were injected in the chamber of 1 m3 and collected in a liquid that are passed through the wet cyclone. The collected concentrate was delivered to the FET-based biosensor causing antigen-antibody reaction with protein through the fluid channel. Then the electrical signals were detected between the two materials using Semiconductor Parameter Analyzer (SPA).