Paper-based microfluidic device for bisphenol A based chemical reaction and image analysis

Bisphenol A (BPA) is a representative xenoestrogenic endocrine disruptor that is widely used in consumer products and remains in wastewater. A simple detection tool is urgently needed that can be used with the naked eye for environmental monitoring in situ. Therefore we studied modification methods of phenol and ferric reagents on a paper-based microfluidic device. The reaction between BPA and ferric reagent mixtures was examined using two types of ferric reagent mixtures (ferric chloride/ferricyanide and ferric nitrate/ferricyanide) at various ferric reagent mixture ratios (1 : 9, 3 : 7, 5 : 5, 7 : 3 and 9 : 1) and concentrations (BPA 100, 300, 500 and 1000 μg/mL and 1-5% ferric reagent mixtures). Verification of this paper-based microfluidic device was analyzed with a UV spectrophotometer. In addition, the changing color of the BPA reaction was demonstrated using histograms of the image statistics including the hue, saturation and value (HSV) analysis. Of the total BPA reactions, the optimal condition was identified as 1% ferric reagent mixture (5: 5 ratio) and 5 μL of BPA loaded onto the paper-based microfluidic device. Moreover, the BPA detection abilities of ferric chloride/ferricyanide and ferric nitrate/ferricyanide were similar to the changing images on the paper-based microfluidic device. The BPA paperbased microfluidic device is expected to be applied in situ and in factories as a low-cost, portable, simple and rapid detection system.