(521f) Microfluidic Enzyme-Linked Immunosorbent Assay For Rapid Detection Of Salmonella Typhimurium In Surface Enhanced Poly(Methyl Methacrylate) Microchannels
AIChE Annual Meeting
2007 Annual Meeting
2007 Annual Meeting of the American Electrophoresis Society (AES)
Biomems and Microfluidics: Sensing, Detection, and Integration
Thursday, November 8, 2007 - 10:15am to 10:36am
An enzyme-linked immunosorbent assay (ELISA) was performed in a microchannel (140 micron width by 125 micron depth) on a poly(methyl methacrylate) (PMMA) microchip. The increased positive charge and amine content on poly(ethyleneimine) (PEI) treated PMMA surface greatly enhanced antibody binding on the microchip, resulting in 3-fold enhancement in the fluorescence signal. With the reduced volume in the microchannel, less sample and reagent (<5 microliter) were consumed, and the incubation time for antigen and antibody binding for the ELISA was also significantly reduced to less than 1 h in each step. Total assay time was reduced to ~2.5 h, from 13 h for ELISA in conventional microtiter plates. The microfluidic ELISA can detect as few as 30 cells of Salmonella typhimurium (with an S/N ratio >7), which is 1-3 orders more sensitive than conventional ELISA methods performed on 96-well and 384-well plates. With the reduced reagent use, enhanced sensitivity, and easy and rapid operation, this microfluidic ELISA assay provides a low-cost alternative to conventional ELISA on 96-well and 384-well plates. Further automatic processing and parallel detection of multiple foodborne pathogens can also be achieved by adopting this platform in a multichannel or microarray format. This microchip can be readily integrated with a low-cost, portable detection system for various field applications, including food safety surveillance, environmental monitoring, and diagnostics for home healthcare.