Inhibiting effect of graphdiyne on Ru(bpy)32+ ECL and its application in drug detection based on the host–guest interaction of cucurbit[8]uril

Graphdiyne (GDY) is considered as another promising carbon material in biosensing field. However, the application of GDY in ECL sensing is in its infancy stage, and different roles of GDY are urgent to be discovered. In this work, strong anodic Ru(bpy)32+ electrochemiluminescence (ECL) was obtained at a cucurbit[8]uril (Q[8]) modified electrode. Although GDY exhibited electrocatalytic effect on the oxidation of Ru(bpy)32+, an apparent inhibiting effect of GDY on the ECL signal was observed due to the energy transfer. An “on-off-on” mode ECL sensor was fabricated to detect pancuronium (PMD) based on the competitive host–guest interaction between ferrocene (Fc), PMD and Q[8]. Fc modified single-stranded DNA was immobilized onto the surface of GDY, which could be attached onto the electrode through the interaction between Fc and Q[8]. The quenching effect of GDY could apparently decrease ECL signal. PMD exhibited stronger combining ability with Q[8] than Fc, and could replace Fc from the cavity of Q[8], leading to the recovery of ECL signal. The variation of ECL intensity changed linearly with the PMD concentration in the range of 10 nM to 50 μM with a detection limit of 5 nM (3σ). The proposed sensor has high sensitivity, outstanding specificity and accuracy, indicating that GDY has promising potential application in ECL sensing field based on its inhibiting effect.