ICN2 Scientists Develop a Novel Immunoassay Based on the Interaction Between Bioluminescent Bacteria and Metal Nanoparticles

by Jose M Arcos

This promising system, called BBLISA, has been created by the NanoBioelectronics and Biosensors Group and could become a low-cost alternative to traditional ELISA tests for the detection of biomarkers and other molecules.

The NanoBiolectronics and Nanosensors Group at ICN2, led by ICREA Prof. Arben Merkoçi, has developed a new biomarker detection system based on the interaction between bioluminescent bacteria and metal nanoparticles. This work has been a collaboration with Prof. Andrea Idili, from the University of Rome Tor Vergata. Their novel immunoassay type has been named BBLISA (Bioluminescent-bacteria-linked immunosorbent assay) and has demonstrated similar sensitivity to conventional ELISA assays, which are widely used today. However, since BBLISA does not require the use of enzymes for molecular detection, it presents a potentially more economical option for clinical analysis. The outcomes of this study have recently been published in the journal ACS Applied Materials and Interfaces, and have been featured on the cover.

Towards the biological test of the future

ELISA immunoassays are among the most widely used analysis methods thanks to their sensitivity, versatility, and speed. They can be used to detect a multitude of biomarkers, even in biological samples. ELISA tests are essential for many fields, such as clinical, pharmaceutical, food, or environmental analysis.

However, the recent COVID-19 pandemic has highlighted the ongoing need for further development of modern immunoassay methods tailored to today's requirements. BBLISA is undoubtedly an important step toward this goal.

How does BBLISA work?

BBLISA uses a similar technology to traditional sandwich ELISA assays. The target molecule binds to two types of antibodies, the capture antibody and the detection antibody, forming a complex. In the case of BBLISA, the detection antibodies are attached to metal nanoparticles, which can absorb the light emitted by the bacteria. Consequently, the bioluminescent signal produced by the bacteria is inversely proportional to the concentration of the sample.

The efficacy and sensitivity of the BBLISA were demonstrated using two different biomolecules: human immunoglobulin G and SARS-CoV-2 nucleoprotein. Furthermore, two types of metal nanoparticles were also tested in the study: gold nanoparticles (AuNPs) and gold-iridium oxide nanoflowers (Au-IrO2 NFs). The use of gold-iridium oxide nanoflowers showed similar sensitivity to conventional ELISA assays.

The BBLISA results open the door to the use of nanomaterials to create new, more sensitive, stable, and cost-effective immunoassay methods in the future.

Reference article

Hu, L., Rossetti, M., Bergua, J. F., Parolo, C., Álvarez-Diduk, R., Rivas, L., Idili, A., & Merkoçi, A. (2024). Harnessing bioluminescent bacteria to develop an enzymatic-free enzyme-linked immunosorbent assay for the detection of clinically relevant biomarkers. ACS Applied Materials & Interfaces. DOI: 10.1021/acsami.4c01744