Iron selenide thin film: Peroxidase-like behavior, glucose detection and amperometric sensing of hydrogen peroxide

Iron selenide (FeSe) thin film was deposited on glass or indium doped tin oxide (ITO) coated glass substrates through chemical bath deposition process from a precursor complex, [Fe3(μ3-O)(μ2-O2CCH2Cl)6(H2O)3]NO3·H2O and was characterized by X-ray diffraction, field emission scanning electron microscopy and UV–vis spectroscopic techniques. Structural analyses revealed that the FeSe film had spherical morphology with average diameter of 30 nm. The film was shown to possess peroxidase-like catalytic activity toward oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of H2O2 and followed Michaelis–Menten kinetics. It was exploited as a simple and cheap material in selective colorimetric method for detection and estimation of glucose in buffer solution. It gave a linear response to glucose over the concentration range from 2 × 10−6 to 3 × 10−5 M with a detection limit of 5 × 10−7 M. Furthermore, the FeSe film, deposited on ITO, performed as good amperometric sensors for detection of H2O2. To compare the catalytic and sensing efficiency of the FeSe film, we have also prepared FeS film under similar conditions.