MnO2 in situ formed into the pores of C-dots/ZIF-8 hybrid nanocomposites as an effective quencher for fluorescence sensing ascorbic acid

A sensitive fluorescent nanosensor based on MnO2 quenching fluorescent carbon quantum dots was facilely developed by MnO2 in situ formed in the pores of C-dots/ZIF-8 hybrid nanocomposite. The C-dots/ZIF-8 hybrid nanocomposite was synthesized via a rapid method within 5 min at room temperature. Then, the MnO2 was directly incorporated into the ZIF-8 framework via redox reaction between the C-dots/ZIF-8 hybrid nanocomposite and KMnO4. The resulting fluorescent nanosensor exhibited a relatively uniform particle size of about 100 nm, good water-dispersibility and a highly selective fluorescence response toward ascorbic acid with a detection limit as low as 83 nM and a linear range of 0.5–8 μM.