Cu(HITP) with peroxidase- and ascorbic acid oxidase-like catalytic activity for fluorescence/chemiluminescence sensing of ascorbic acid.

Nanomaterials with intrinsic enzyme mimicking activity have achieved widespread application. However, developing novel nanomaterials with multienzyme mimicry activity remains challenging. Herein, Cu(HITP) (HITP = 2,3,6,7,10,11-hexaiminotriphenylene) with ascorbic acid oxidase (AAO)- and peroxidase (POD)-like activity are successfully synthesized. Cu(HITP) exhibits excellent AAO-like activity and can specifically catalyze the oxidation reaction of ascorbic acid (AA). Dehydroascorbic acid (DHAA) obtained from the oxidation of AA is allowed to react with nonfluorescent o-phenylenediamine (OPD) to form 3-(1,2-dihydrox-yethyl) furo[3,4-b]quinoxaline-1-one (DFQ) with strong fluorescence emission. Moreover, Cu(HITP) is able to catalyze the chemiluminescence (CL) reaction of ABEI-HO to generate a strong and glow-type emission based on its POD activity. Inspired by the multienzyme mimicry activity of Cu(HITP), the simple and sensitive fluorescence and chemiluminescence sensing platforms are successfully constructed and applied for the detection of AA. The sensors show high sensitivity and excellent selectivity. We believe that this multienzyme mimicry activity nanomaterial not only can be used to construct the multiple-mode biosensing platform, but also enables the extensive applications in the fields of biomedicine, energy, and environment.