Structural tuning of MgFe2O4/PVP@ZIF-67@Ag nanozymes for colorimetric detection of sulfide ions

Herein, the structural identity, morphological characteristics, and catalytic performance of MgFe2O4/PVP@ZIF67@Ag hybrid nanostructures for colorimetric biosensing of S2- were investigated. XRD analysis confirmed the crystalline arrangement, with characteristic diffraction peaks observed for ZIF-67, MgFe2O4/PVP, and Ag. FT-IR spectroscopy revealed distinctive chemical compositions, while SEM and TEM analyses provided insights into the morphology and component distribution. MgFe2O4/PVP@ZIF-67@Ag, as a colorimetric biosensor, exhibited remarkable sensitivity in detecting H2O2 and S2- . Extremely low detection limits (LOD) for S2-ions were achieved at 57 nM in a wide range of 0-100 mu M. The obtained Km values were 0.142 and 0.184 mM and the Vmax was 0.568 x 10- 8 M/s and 0.277 x 10- 8 M/s, vs. TMB and H2O2, respectively. Recyclability was evaluated by reusing the nanomaterials several times; there was no significant decrease in absorbance when the magnetic composites were utilized ten times. The new, robust, and convenient assay systems can be widely utilized for the identification of other target molecules.