Au@NiFeMOFs as the signal quencher of Au@g-C3N4NSs composite for sensitive on-off electrochemiluminescence immunosensing of beta-2-microglobulin

In this study, an electrochemiluminescence resonance energy transfer (ECL-RET) immunosensor was constructed to detect beta-2-microglobulin (B2M). As a donor-acceptor pair, a carbon nitride nanosheet modified with gold nanoparticles (Au@g-C3N4NSs) and a nickel- and iron-based organic framework modified with gold nanoparticles (Au@NiFeMOFs) were prepared. The sandwich immunosensor was successfully constructed so that ECLRET occurred between Au@NiFeMOFs and Au@g-C3N4NSs. The ECL intensity of the immunosensor decreased with the increase the B2M concentration due to the low conductivity of B2M. The linear range of the ECL-RET immunosensor was from 10 fg/mL to 10 ng/mL, and the limit of detection was 2.3 fg/mL (S/N = 3). The developed immunosensor had high sensitivity, high specificity, and excellent stability. It could realize the sensitivity test of B2M and provide a novel idea for the detection of biomarkers.

Automated summary

An electrochemiluminescence resonance energy transfer (ECL-RET) immunosensor was constructed to detect beta-2-microglobulin (B2M) by using carbon nitride nanosheet and nickel- and iron-based organic framework modified with gold nanoparticles. The sandwich immunosensor showed a decrease in ECL intensity with increasing B2M concentration due to low conductivity of B2M. The ECL-RET immunosensor had a linear range of 10 fg/mL to 10 ng/mL and a limit of detection of 2.3 fg/mL (S/N = 3), exhibiting high sensitivity, specificity, and stability for B2M detection.