Synthesis of silver nanoparticles from Phlogacanthus turgidus extract and applying in hydrogen peroxide sensor

Abstract

Introduction: Among metal nanoparticles (MNPs), silver nanoparticles (AgNPs) have partical attention due to their excellent electrical and optical properties. Notably, colorimetric sensors incorporating metal nanoparticles have garnered significant attention from scientists in biochemical analysis, offering a simple solution. Here, we report the use of AgNPs applying hydrogen peroxide (H₂O₂) sensor. Methods: The AgNPs were synthesized using Phlogacanthus turgidus leaf extract, H₂O₂ oxidized colorless TMB into blue ox-TMB, the reaction was catalyzed by AgNO₃. Measuring the resulting solution spectrophotometrically helped to determine the concentration of ox-TMB, thereby determining the concentration of H₂O₂ produced. Results: The UV-Vis spectrum of AgNPs synthesized from Phlogacanthus turgidus leaf extract exhibited a prominent absorption peak at 427 nm. The linear range was determined in 100 – 300 µM. The linear regression equation is y = 0.91574 + 3.10484×10^-4 C_H2O2 with a SD value of 0.00438. The result showed that the limit of detection (LOD) of H₂O₂ through the color reaction between the 3,3’,5,5’-tetramethylbenzidine (TMB) and H₂O₂ in AgNPs catalysis was 46.55 µM and the limit of quantification (LOQ) was 141.07 µM. Conclusion: Based on the results of optimal conditions for TMB oxidation in the presence of AgNPs, we can evaluate the applicability as a H₂O₂ sensor.