Flow-through microfluidic digital impedance detection

A Teflon coated flow cell has been designed for detection of analyte concentration and liquid identification of solvents. An AC voltage is applied across the flow cell to generate a current that is displayed in real time and used in solvent analysis. Experimental methods include injecting different concentrations of analytes in a flow path and analyzing current peaks that result as analytes enter the cell. The method provides a highly sensitive solvent identification and an alternative to more expensive and UV-dependent microfluidic sensing of analytes.