Room temperature phosphorimetric determination of bromate in flour based on energy transfer

A simple and general procedure is proposed to carry out the incorporation of both the donor and acceptor molecules in an appropriate solid material (sensing phase) through the co-immobilization of the species in a sol-gel inorganic matrix. The optimum amounts of the sol-gel precursors, including silica precursors, type of catalysis, and concentrations of donor and acceptor molecules, have been evaluated in order to obtain the best analytical features of the proposed optosensor for bromate determination. The highly stable developed sensing phase shows a selective and reversible response towards bromate even in presence of dissolved oxygen (a well-known quencher of the RTP). The calibration graphs were linear up to 200 mg L−1, with a detection limit for bromate dissolved in aqueous medium of 0.2 mg L−1. Sample throughput of the proposed optosensor was about 18 measurements h−1. Application of the developed sensing phase was successfully proved for the detection of bromate ions in commercial flours, obtaining good recoveries.