Hemin@carbon dot hybrid nanozymes with peroxidase mimicking propertiesfor dual(colorimetric and fluorometric) sensing of hydrogen peroxide, glucose and xanthine.

Abstract

The multifunctional hemin@carbon dot hybrid nanozymes (hemin@CD)with simultaneous peroxidase-like activity and fluorescencesignalling property was prepared for the first time. Based on these properties, hemin@CD was applied to develop a dual-channel fluorescent probe for H2O2 and H2O2-based biocatalytic systems. By virtue of the peroxidase-like activity, hemin@CD can catalyze the oxidative coupling of 4-aminoantipyrine with phenol in the presence of H2O2 to form a pink-redquinoneimine dye with a maximum absorbance at 505nm. Under the excitation wavelength of480nm, thegreen fluorescence of hemin@CD peaksat 540nm andis quenched by the generated quinoneimine dye due to an inner filter effect, and also by H2O2 because of dynamic quenching. Thus, a colorimetric and fluorimetric dual-channel optical probe for H2O2 is obtained. Due to the glucose/xanthine transformations under formation of H2O2 by the relevant oxidase catalysis, the probe can be applied for detection of glucose and xanthine. The colorimetric detection limits for H2O2, glucose and xanthine are 0.11, 0.15, 0.11μM, and theand fluorimetric detection limits are0.15, 0.15, 0.12μM, respectively. Graphical abstractSchematic representation of the colorimetric and fluorimetric dualprobe for H2O2, glucose and xanthine based on the multifunctional emin@carbon dot) hybrid nanozymes with simultaneous peroxidase-like activity and fluorescencesignalling property.