Fabricated nanoplatform of Cu(II)-functionalized mimetic-peroxidase with catalytic property toward sensitive monitoring of hydrogen peroxide

Abstract

A novel strategy toward monitoring of hydrogen peroxide (H2O2) through carbonaceous nanoplatform architectures (herein named as Cu(II)-LPQDs) is presented. Cu(II)-LPQDs were constructed by coupling Cu(II) complex with l-phenylalaninamide (LPN) functionalized N-doped carbon quantum dots (LPQDs). We have designed an efficient metal-ion-controlled mechanism to control peroxidase mimetic catalytic reactions. As the range of electron delocalization enhanced, the catalytic activity and stability of the mimetic peroxidase based on the Cu-N coordination unit increase significantly. By capturing the appearance of colorimetric and fluorescence changes, the detection of H2O2 in biological samples by qualitative and quantitative analysis is successfully realized. In our work, the detection limits of H2O2 by colorimetric and fluorescent methods are 80 nM and 2.5 μM, respectively. Its ultrasensitive-bidirectional properties are well described in-situ measurement in real samples and biological cells. The arresting feature of this method is green, simple, speedy, selective, sensitive and stable. Our findings provide clues to the intelligent nanoplatforms for the preparation of metalloenzymes without the use of noble metal elements for sensing applications and exhibit the highest peroxidase mimetic activity compared to other transition metals.