Highly sensitive electrochemiluminescent sensing platform based on graphite carbon nitride nanosheets for detection of pyrophosphate ion in the synovial fluid

Abstract Graphite carbon nitride nanosheets (g-C 3 N 4 NSs) are the promising metal-free polymer-like semiconductor nanomaterials, which exhibit excellent electrochemiluminescence (ECL) behavior. The g-C 3 N 4 NSs modified the glass carbon electrode showed the obvious ECL response using 10 mM S 2 O 8 2− as the co-reactant at the scan rate of 0.1 V/s. The presence of Cu 2+ would quench ECL emission due to the photo induced electron transfer (PET). Pyrophosphate anion (PPi), an important anion in several bioenergetics and metabolic processes, can chelate with Cu 2+ with a strong affinity. The introduction of PPi could release Cu 2+ from Cu 2+ -g-C 3 N 4 NSs system, resulting in the ECL recovery. The dosage of Cu 2+ and the ECL recover time were further investigated. Under the optimized condition PPi can be detected in the range of 2.0–800 nM with the detection limit of 75 pM based on 3ơ/slope. This ECL sensor also possessed good selectivity to PPi, and has been used to detect PPi in the synovial fluid.