Naked-eye quantitative assay on paper device for date rape drug sensing via smart phone APP

The present work aimed for the development of a low-cost, naked eye assay indicating the presence of date-rape drug (DRD) in the alcoholic beverages. A microfluidic paper-based analytical device (μPAD) was used as the platform to prepare this sensor. Bromocresol green (BCG; 0.04% and 5%) was used as the indicator for the colorimetric assay of DRD,.i.e., ketamine. The developed paper based strip was coated with BCG and further ketamine solution. The complexation between dye and drug lead to the change in color of the strip. The color also varied upon change in the concentration of ketamine (0.1 M, 0.01 M, 0.001 M) in the solution which forms the basis of the detection. The color change of BCG at 0.04% was not much detectable, therefore, 5% BCG concentration was chosen for development of the colorimetric sensor. The device was linked with a smart phone app which depicts the change in color and displays whether the beverage is safe or unsafe for drinking. In addition, the app sends message to selected number, if the person is in danger.