A highly selective melamine sensor relying on intensified electrochemiluminescence of the silica nanoparticles doped with [Ru(bpy)3]2+/molecularly imprinted polymer modified electrode

[Display omitted] •RUDS are well-dispersed in the MIP film by a simple ultrasonication method.•Coupling of MIP-based extraction and ECL method with high selectivity and sensitivity.•RUDS/MIP GCE displays high recognition ability, good reproducibility, and good stability.•The proposed ECL approach was successfully used to analyze MEL content in milk. In this work, a novel and highly selective molecularly imprinted sensor for the detection of melamine in milk using electrochemiluminescence (ECL) is reported. The preparation was carried out by modification of a glassy carbon electrode with a composite of silica nanoparticles doped with [Ru(bpy)3]2+ (RUDS) and molecularly imprinted polymer (MIP). The keys of the sensor were to employ RUDS as an ECL luminophore to prevent [Ru(bpy)3]2+ leaching from the modified electrode and MIP as a material for selective recognition. Taking advantage of the MIP pre-concentration effect, melamine could be extracted from the solution and detected by the resulting ECL signal enhancement of [Ru(bpy)3]2+. Under optimized conditions, the relative ECL signal was proportional to the logarithm of melamine concentration in the range of 1×10−12–1×10−7molL−1, with a detection limit as low as 5×10−13molL−1. Compared with the RUDS/non-imprinted polymer, the RUDS/MIP modified electrode displayed high recognition ability, good reproducibility, and stability. To verify its reliability, the fabricated ECL sensor was used for determining the concentration of melamine in milk.