A Novel Electrochemiluminescence Sensor Based on NiCo NCs@CN QDs Nanocomposites with Poly-L-cysteine As Co-reaction Accelerator for Ultrasensitive Detection of Vitamin K

A novel electrochemiluminescence (ECL) sensor based on eco-friendly CN QDs was constructed for the ultrasensitive detection of VK. The synthesized NiCo nanocages (NiCo NCs) with large specific surface area and high catalytic activity were used to effectively load CN QDs, forming the nanocomposites (NiCo NCs@CN QDs) with good luminescent properties. After grafting NiCo NCs@CN QDs onto poly-L-cysteine film, the ECL system achieved multiple signal amplification, which was due to the fact that poly-L-cysteine as a co-reactant accelerator sped up the generation of more SO from SO. Under the optimal conditions, the ECL sensor exhibited a wide detection range for VK from 1.0 × 10 to 5.0 × 10 mol/L and a low detection limit of 1.65 × 10 mol/L. Furthermore, the spiked recoveries in milk, apples, and celery were in the range of 83.50 %-105.32 %, proving the feasibility of the prepared ECL sensor in actual sample detection.