Hexagonal Cobalt Oxyhydroxide-Carbon Dots Hybridized Surface: High Sensitive Fluorescence Turn-on Probe for Monitoring of Ascorbic Acid in Rat Brain Following Brain Ischemia

In this study, we report novel and efficient fluorescence probe synthesized by Tris(hydroxymethyl)aminomethane-derived carbon dots :(CDs)-modified,hexagonal cobalt oxyhydroxide(CoOOH) nanoflakes (Tris-derived CDs-CoOOH) for monitoring of cerebral ascorbic acid (AA) ill brain micro dialysate. The as-prepared Tris-derived CDs with the fluorescence quantum yield of 7.3%, prepared by a one-step pyrolysis strategy of the sole precursor and used as the signal output. After being hybridized :With CoOOH nanoflakes to form Tris-derived CDs-CoOOH:14, the luminescence Of the Tris-derived CDs can be efficiently quenched by CoOOH via fluorescence resonance energy transfer (FRET). Due to the specific redox reaction between the enediol group. of AA and hexagonal CoOOH nanoflakes, AA can reduce the hexagonal CoOOH nanoflakes in the Tris-derived CDs-CoOOH and lead to collapse of the hybrized structure, then the release of Tris-derived CDs, and thus finally the fluorescence recovery; Moreover, cobalt ions (II); generated by CoOOH,nanoflakes oxidizing AA, almost have no Obvious interference on the fluorescence probe, i.e, Tris-derived CDs, Which could be ascribed to the surface of Tris-derived CDs containing, a few strong chelation groups such as amino/carboxyl/thiol, groups, instead of plenty of OH groups with weak chelation with CO2+. On the basis of this feature, the Tris-derived CDs-CoOOH fluorescent probe demonstrates a linear range from 100 nM to 20 mu M with the detection limit of similar to 50 nM, i.e., With an improved sensitivity toward AA detection. Compared with other turn-on fluorescent methods using convenient fluorophore-nitroxide fluorescent probes for detection of AA, the method demonstrated here possesses a facial synthesis route, lower limit of detection, and wider linear range, which validates sensing of AA in the cerebral systems during the calm/ischemia process. This study provides a fluorescence assay for the simple yet facial detection of AA in the cerebral systems and assists in the understanding of the biological processes in the physiological and pathological study.