Colorimetric Determination of Hydrogen Peroxide Based on the Enzymatic Properties of Garlic and Cuscuta campestris Extract Plants

Addressing the increasing demand for efficient enzyme‐based catalysis and biomarkers, this study investigates garlic ( Allium sativum , AS) and Cuscuta campestris (CC) extracts as potent biocatalysts. For the first time, their potential in hydrogen peroxide (H 2 O 2 ) detection and quantification is explored through catalytic activity, substrate affinity, and sensor development. AS and CC extracts were prepared via stirring and sonication, then employed as peroxidase‐mimicking enzymes. Their catalytic ability was assessed by oxidizing 3,3,5,5‐tetramethylbenzidine (TMB) in the presence of H2O2. Kinetic analysis revealed that both extracts followed Michaelis‐Menten behavior, exhibiting high affinity for TMB and H2O2. A novel colorimetric H2O2 sensor was developed using these plant extracts. The AS‐based sensor showed a linear detection range of 11.29–148 µM with a detection limit of 39 nM, while the CC‐based sensor achieved a 0.6–168 µM range with a 4.5 nM detection limit. Practical applicability was demonstrated through successful H2O2 detection in human serum and disinfectant samples, yielding accurate and reliable results. This simple, sensitive extract/TMB/H2O2 colorimetric system offers significant promise for applications in clinical diagnostics and food environment monitoring.