Research data for: Microfluidic paper-based analytical device for simultaneous determination of calcium and magnesium ions in human serum

Research data for: Microfluidic paper-based analytical device for simultaneous determination of calcium and magnesium ions in human serum

Scans of paper-based sensors were acquired using Epson V37 flatbed scanner (Suwa, Japan). Scanning resolution was 600 dpi.

Photos of paper-based sensors were taken with Samsung Galaxy M31s smartphone (Suwon, South Korea) and Footej Camera 2 application with the following settings:ISO 400, shutter speed 1/250 s. and auto white balance.To provide constant lightning conditions, the sensors were placed in a white illumination box (Puluz, China), which had two LED strips (20 LEDs each, 1100 lumen in total, 5500 K color temperature) placed on the opposite edges.

To obtain numerical values on color scans or photos were analyzed using ImageJ software (National Institutes of Health, USA). To transform the images from RGB to HSV color space Color Space Converter plug-in was used. Channel intensity in each color space was measured in a circular region of interest (ROI), around 140 pixels in diameter, using either RGB Measure function for RGB color space images or Measure function for images in HSV color space. Adequate channel intensities were averaged and treated as analytical signal.