FOx BIOSYSTEMS sandwich assays applications icon

The unique fiber-optic design of the FOx BIOSYSTEMS probe allows the implementation of sandwich-style bioassays using gold nanoparticles. This instantly amplifies the surface plasmon resonance signal without the lengthy enzymatic reaction incubations of an ELISA, providing increased detection sensitivity and speed.

Amplifying the signal in this way allows fast, physiologically relevant detection. Therefore, the FOx BIOSYSTEMS technology can detect physiologically active levels of biotherapeutics quickly and accurately, allowing for rapid dose adjustment in preclinical and clinical research and testing.

Case study: FO-SPR sandwich assay

Infliximab (IFX) is a monoclonal antibody used for the treatment of inflammatory bowel disease. Optimizing the therapeutic outcome requires concentration measurements which are currently obtained using the slow ELISA or less sensitive lateral flow-based immunotherapy techniques.

Tests using the FO-SPR probes and an IFX-specific capture antibody showed that surface plasmon resonance alone was unable to detect concentrations lower than 1 μg/ml. Using the same technology with SPR signal amplification via gold nanoparticles conjugated to detection antibody, a limit of detection (LOD) of 2.2 ng/ml was obtained in 100-fold diluted serum.

Sandwich bioassays on FO probe surface. The FOx BIOSYSTEMS instrument is capable of running standard bioassays that provide real-time, label-free data (A) or gold nanoparticle sandwich assays to boost the sensitivity and speed of the surface plasmon resonance signal (B).

Contact us today to see how we can help you.

Contact us