New Optical Sensing Reagent of Bis(2-oxidobenzylidene)benzenesulfonohydrazide Nickel(II) for the Detection of Formaldehyde in Fish

An optical chemical sensor for the determination of formaldehyde in fish was developed based on bis(2-oxidobenzylidene)benzenesulfonohydrazide) nickel(II) (Ni(SALBSH)2).The Ni(SALBSH)2 complex was immobilised onto a PVA/Chitosan membrane and designated as Ni(SALBSH)2-PVA/Chi Probe.The absorbance intensity of the Ni(SALBSH)2-PVA/Chi Probe decreased at a wavelength of 326 nm in the presence of formaldehyde.The reaction of the Ni(SALBSH)2-PVA/Chi Probe and formaldehyde was optimal at pH 5 and a complex concentration of 300 mgL -1 .The dynamic range of the Ni(SALBSH)2-PVA/Chi Probe for formaldehyde was 20 -500 mgL -1, and the limit of detection was 2.52 mgL -1 .This probe is suitable for detecting individual analytes in clean aqueous solutions but is not directly applicable to complex matrices, such as fish homogenates.