Synergistic effect of fullerenol and light enhanced the peroxidase-like activity of Fe(III) for colorimetric detection of deferasirox

To improve the catalytic activity of mimic enzymes for better application in biosensing analysis, researchers have developed different regulatory methods. Still, the attention is focused on a single mode of regulation, while the dual mode of regulation through material and external stimulus is promising. Here, we develop a synergistic strategy to improve the catalytic activity of Fe(III) by introducing fullerenol and light to facilitate the conversion of Fe(III) to Fe(II). The peroxidase-like activity of Fe(III) was greatly improved under the dual stimulation of fullerenol and light by the exploiting enzyme activity test. Then, the analysis of the possible catalytic mechanism showed that fullerenol may be a suitable electron donor and complexing agent, which can accelerate the Fe(III)/Fe(II) cycle by forming Fe(III)-fullerenol complex with Fe(III), thereby promoting the generation of Fe(II) to accelerate the decomposition of H2O2 to produce hydroxyl radicals. Notably, this process can be significantly enhanced under light due to the photosensitive property of fullerenol. Ultimately, based on the strong coordination ability of deferasirox (DFX) to specifically inhibit the enzyme-like activity of Fe(III), a colorimetric sensing platform for the selective detection of DFX was constructed within 0.08-12 µM, and applied to the urine samples of thalassemia patients with satisfactory results. This work not only provides new insights into the regulation of enzyme activity, but also provides an important reference for guiding the clinical use of DFX.