Enhanced cathodic electrochemiluminescent microcystin-LR aptasensor based on surface plasmon resonance of Bi...

Sensitive testing for Microcystins-LR (MC-LR) is needed because of its serious environmental and human health hazards. In this work, a new type of surface plasmon resonance (SPR) enhanced cathodic electrochemiluminescence (ECL) aptasensing platform was designed in which boron and nitrogen co-doped graphene quantum dots (BN-GQDs) were used as the luminary and bismuth nanoparticles (Bi NPs) were used as the SPR source. SPR effect of non-precious metal Bi NPs can induce and enhance ECL signal of BN-GQDs because the fluorescence spectrum of BN-GQDs overlaps well with the ultraviolet-visible absorption spectrum of Bi NPs. On this basis, a sensitive sensing system based on the Bi NPs and BN-GQDs was established for MC-LR detection. The results showed that the ECL sensing signal obtained was linear with the negative logarithm of the target MC-LR concentration in the range of 0.01-5000 pM, and the detection limit was 0.003 pM. In addition, the sensor had high stability and good reproducibility, which can be applied to the detection of MC-LR in actual samples. The method had good specificity and can not be disturbed by its homolog, which can be used for sensitive and reliable detection of complex samples.