A fluorescent sensor, (E)-2- (((5-(5-methoxy-1H-benzodimidazol-2-yl)thiophen-2-yl)methylene)amino)phenol (OMTP), was designed for direct application to the surface of onions using a smartphone for real-time monitoring of iron content. The detection limit was as...
Duan et al. (Thu,) studied this question.