Enzyme-free colorimetric detection of biothiols based on the photoinduced oxidation of 3,3′,5,5′-tetramethylbenzidine

Equipment-free determination of ascorbic acid based on the UV-induced oxidation of 3,3′,5,5′-tetramethylbenzidine in a paper-based analysis device

“…As we know, TMB is the most commonly used chromogenic substrate due to its low cost and large molar absorption coefficient (oxidation product of TMB, e 652 nm = 39 000 M cm À1 ). [28][29][30] As shown in Scheme 1, filter paper is pre-treated by TMB. It could be rapidly oxidized upon UV irradiation to a blue color as TMB is a self-photosensitizer.…”