FeSe2/rGO nanohybrids were prepared via in situ one-pot synthesis using the hydrothermal method and were assessed for their potential for peroxidase-like activity. Structural and morphological analysis using FE-SEM and TEM confirmed the successful in situ growth and uniform distribution of FeSe2 NPs onto the rGO nanosheet matrix. Furthermore, the FeSe2/rGO nanohybrids showed superior and enhanced peroxidase-like activities compared to the bare FeSe2, as demonstrated using two substrates, 3,3',5,5'-tetramethylbenzidine (TMB) and o-phenylenediamine (OPD). Michaelis-Menten kinetics showed a significantly lower Km of 0.00952 mM for TMB and 7.62 mM for H2O2, along with a high Vmax of 6.48 × 10-8 M s-1 (TMB) and 1.706 × 10-6 Ms-1 (H2O2) for FeSe2/rGO, outperforming bare FeSe2 and several other reported nanozymes. The kinetic parameters showed a strong substrate affinity and improved catalytic efficiency. Mechanistic study using terephthalic acid (fluorescent probe) revealed that •OH is majorly responsible for substrate oxidation, which is significantly enhanced by the synergistic effect of FeSe2 and rGO. Furthermore, in support of our experimental results, molecular docking studies with multiple peroxidase proteins also showed significantly higher binding affinities for FeSe2/rGO (-9.9 to -11.9 kcal mol-1), as compared to FeSe2 (-4.8 to -9.1 kcal mol-1). Overall, this work highlights FeSe2/rGO as a robust peroxidase mimic and efficient nanozyme with strong potential for colorimetric sensing and catalytic performance.
Maurya et al. (Wed,) studied this question.