A simple platform with moving drops for downscaling chemical analysis incorporating smartphone detection.

A simple cost-effective device for downscaling chemical analysis with microliter-scale dropwise handing and smartphone detection is proposed. The platform was made from easily available materials. Drops of constant volume of analyte and reagent were placed onto a channel then moved by gravity force to mix and react with each other. The color change due to reaction was monitored with a smartphone. Assays of iron, copper and phosphate employing the platform were demonstrated with 1,10-phenanthroline, bicinchoninic acid and molybdate reagents, respectively. Kinetic study was also demonstrated for this simple device.