Sensitive and cost-effective colorimetric sensor based on enzyme mimic MoS2@CoTiO3 nanocomposite for detection of hydrogen peroxide in milk and tap water

Although hydrogen peroxide (H2O2) is essential for biochemical reactions and industrial processes but excessive levels can be hazardous to health. As a result, developing a reliable, selective, and sensitive H2O2 detection method remains challenging. This study proposes an inexpensive, portable, and rapid colorimetric sensor for quick H2O2 detection based on a filter paper-based platform and novel nanozymes named Molybdenum disulfide and Cobalt titanate (MoS2@CoTiO3) nanocomposite.Different analytical techniques were used to evaluate the interaction between the material and analyte, including UV-Visible spectrophotometry, Fourier transform infrared spectroscopy, Scanning electron microscopy, X-Ray diffraction, Zeta potential, and Dynamic light scattering. The characterization study proved the proposed material's appropriateness for sensing purposes. The combined action of MoS2 and CoTiO3 components revealed intrinsic peroxidase-like activity, allowing for the visible oxidation of 3,3 ',5,5 '-tetramethylbenzidine (TMB). Several optimization parameters were evaluated, including TMB concentration (25 mM), incubation time (20 min), pH (7.0), and nanocomposite (3.0 mg) and gel (0.2 g) concentrations. Consequently, due to its peroxidase-like activity, the MoS2@CoTiO3 nanocomposite achieved a lower detection limit (LOD) of 0.01 mu M. The platform displayed adequate selectivity against potential interferants in biological samples, with excellent recovery rates ranging from 93.3 % to 98.3 %. The use of lowcost paper-based porous substrates for sensing has proven to be a versatile option for onsite health and environmental monitoring, providing an alternative to costly and complicated instrumentation.