Polymethacrylate Colorimetric Sensor for Evaluation of Total Antioxidant Capacity

A new colorimetric sensor using an immobilized chromogenic redox reagent was devised for measuring the total antioxidant level in a liquid sample without requiring sample pretreatment. The reagent, Fe(III) – 1,10-phenanthroline (Fe(III)-phen), was immobilized into a polymethacrylate matrix (PMM), and the absorbance changes associated with the formation of the highly colored Fe(II)-phen chelate as a result of reaction with antioxidants was measured at 510 nm. The developed optical sensor was used to screen total antioxidant capacity of some black and green teas, red and white wines.