FeTOMPP with Peroxidase-Like Activity as Peroxidase Mimics for Colorimetric Sensing of H2O2 and Ethanol

In this study, FeTOMPP (Tetrakis(4-methoxyphenyl) phenylporphyrinatoiron(III)) was synthesized and investigated for its peroxidase-like activity. The catalytic performance of FeTOMPP as a peroxidase mimic was explored by utilizing the colorless peroxidase substrate, 3,3',5,5'-tetramethylbenzidine (TMB), in the presence of hydrogen peroxide (H2O2). The oxidation of TMB by FeTOMPP resulted in the formation of its blue oxidized state. This enzymatic reaction was employed for the quantitative detection of H2O2, with a linear detection range spanning from 1.0 to 100 µM. The detection limit achieved using FeTOMPP as the catalyst was determined to be 2.4 µM. Furthermore, kinetic studies were conducted to investigate the interaction between FeTOMPP and H2O2. The results indicated that FeTOMPP exhibited favorable affinity towards H2O2, further highlighting its potential as a peroxidase mimic. In addition to its peroxidase-like activity, a simple and sensitive visual and colorimetric method was developed for the detection of ethanol by combining FeTOMPP with alcohol oxidase. The method relied on the use of TMB as the substrate. Ethanol-containing samples were subjected to the enzymatic reaction, resulting in the generation of a color change. The detection of ethanol was achieved with a minimum detection limit of 0.95 % v/v, and the linear range for quantification extended from 0 to 15 % v/v. This study demonstrates the potential application of FeTOMPP as a peroxidase mimic for the sensitive detection of H2O2 and the development of a colorimetric method for ethanol detection. The findings highlight the versatility and promising capabilities of FeTOMPP in various analytical and diagnostic applications. HIGHLIGHTS The potential application of FeTOMPP as a peroxidase mimic for the sensitive detection of H2O2. The development of colorimetric method for ethanol detection by combining FeTOMPP with alcohol oxidase. GRAPHICAL ABSTRACT