Dr. Andrade from University of Illinois has developed a rapid, cost effective, paper-based assay that interfaces with a smartphone for the detection and quantification of common iron in fortified grains This invention can quantify iron content is a cheap cost-effective method for areas which lack access to laboratory equipment and trained personnel. Dr. Andrade's group has improved upon this technology by streamlining the sensor fabrication process and improved upon the detector sensitivity. Furthermore, this technology can now quantify iron released from Lucky Iron Fish, iron metal electrolytic, as well as Sodium Iron EDTA.