The development of paper microfluidic devices for presumptive drug detection

A paper microfluidic device has been developed for the presumptive testing of seized drugs in forensic casework. The procedure involves creating hydrophilic channels on chromatographic paper using wax printing and thermal lamination. The channels are connected to a single stem that draws an unknown analyte solution up into 6 different lanes. A different colorimetric reaction occurs within each lane, permitting the multiplexed detection of a variety of different compounds, including cocaine, opiates, ketamine, and various phenethyl amines. Furthermore, the linear orientation of the lanes permits series of reactants to be placed in each channel, enhancing stability and permitting sequential interaction with the analyte as the solvent front passes through each individual reagent. The resultant device was characterized for sensitivity and tested with a variety of common interferences and drug diluents. It should prove a useful device for screening seized drugs.