Low-cost and portable colorimetric platform for simultaneous detection of Fe, methanol, and total phenols in wine

A multi-channel colorimetric device was developed for the low-cost and simultaneous determination of three important parameters in wine safety and quality- total iron (Fe), methanol (MeOH), and total phenols. The detection was performed by assembling light-dependent resistors and light-emitting diodes in a 3D printed chamber, which measured colorimetric signals horizontally transmitting through the microwells of an 8-well strip. This device demonstrated linear relationships (R² greater than 0.99) for all analytes with detection limits of 0.04 mg/L, 2.26 mg/L, and 3.40 mg/L for Fe, MeOH, and total phenols, respectively. Wine sample measurements showed that the multi-channel device was as accurate as the professional spectrophotometer and could simultaneously provide the three target concentrations to facilitate the analysis. With the merits of low fabrication cost and ease of use, this device could be used as a general platform for multiple-target detection, demonstrating great potential for application in food analysis.