Simple solid-phase spectrophotometric method for free iron(III) determination

A simple and rapid solid-phase spectrophotometric procedure to determine free Fe(III) in environmental and biological samples is proposed. In particular, a deferoxamine (DFO) self assembled monolayer on mesoporous silica (DFO SAMMS) is developed and here applied as sensor for iron(III). The solid product became brownish when put in contact with iron(III) solutions; so an immediate application as colorimetric sensor is considered. In order to optimise the DFO SAMMS synthesis and to obtain the best product for iron(III) sensing, a factorial experimental design is performed selecting the maximum absorption at 425 nm as response. The robustness of the spectrophotometric method is also proved.