Sensing performances of oligosilane functionalized fluorescent film to nitrobenzene in aqueous solution

A fluorescent film fabricated by monolayer attachment of oligo(diphenylsilane) on glass slide surfaces was utilized for the sensitive, selective, and reagent-less detection of nitrobenzene (NB) in aqueous phase. Chemical immobilization endows the film a satisfying stability and avoids the leaching problem, which is a key factor that limits the sensing application of fluorescent films fabricated via a physical method in solution phase. It has been demonstrated that the fluorescence emission of the film as prepared is much more sensitive to NB in aqueous phase than to other nitroaromatic compounds (NACs), including 2,4,6-trinitrotoluene (TNT), 2,4-dinitrotoluene (DNT) and picric acid (PA), and the detection limit to NB reaches 1.5 × 10 ^-10 mol/L This exceptional selectivity has been rationalized by considering the possible hindrance effect induced by the compact conformation of the flexible less-polar spacer and the sensing element, the oligomer. Further experiments indicate that the sensing process is free of interference from common solvents like benzene, toluene, ethanol and methanol. Furthermore, the process is fully reversible.