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

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 (H₂O₂) 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.