A novel electrochemiluminescence sensor based on NiCo NCs@C3N QDs nanocomposites with poly-L-cysteine as co-reaction accelerator for ultrasensitive detection of vitamin K1

Abstract

A novel electrochemiluminescence (ECL) sensor based on eco-friendly C₃N QDs was constructed for the ultrasensitive detection of VK₁. The synthesized NiCo nanocages (NiCo NCs) with large specific surface area and high catalytic activity were used to effectively load C₃N QDs, forming the nanocomposites (NiCo NCs@C₃N QDs) with good luminescent properties. After grafting NiCo NCs@C₃N 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 SO₄^−• from S₂O₈²⁻. Under the optimal conditions, the ECL sensor exhibited a wide detection range for VK₁ from 1.0 × 10⁻⁹ to 5.0 × 10⁻⁵ mol/L and a low detection limit of 1.65 × 10⁻¹⁰ 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.