A rapid point-of-care optical ion sensing platform based on target-induced dye release from smart hydrogels

We report here a rapid and versatile metal ion analytical platform based on the dye release from hydrogels entrapping ion-selective microdroplets. Using Ca2+, Pb2+, and Na+ as model ions, the ion-selective hydrogels were developed in combination with four positively charged dyes, making the hydrogels highly promising for point-of-care diagnostics as well as environmental monitoring.