Using A Fiber Optic Particle Plasmon Resonance Biosensor To Determine Kinetic Constants of Antigen–Antibody Binding Reaction

In this paper, one simple and label-free biosensing method has been developed for determining the binding kinetic constants of antiovalbumin antibody (anti-OVA) and anti-mouse IgG antibody using the fiber optic particle plasmon resonance (FOPPR) biosensor. The FOPPR sensor is based on gold-nanoparticle-modified optical fiber, where the gold nanoparticle surface has been modified by a mixed self-assembled monolayer for conjugation of a molecular probe reporter (ovalbumin or mouse IgG) to dock with the corresponding analyte species such as anti-OVA or anti-mouse IgG. The binding process, occurring when an analyte reacts with a probe molecule immobilized on the optical fiber, can be monitored in real-time. In addition, by assuming a Langmuir-type adsorption isotherm to measure the initial binding rate, the quantitative determination of binding kinetic constants, the association and dissociation rate constants, yields k a of (7.21 ± 0.4) × 103 M–1 s–1 and k d of (2.97 ± 0.1) × 10–3 s–1 for OVA/anti-OVA and k a of (1.45 ± 0.2) × 106 M–1 s–1 and k d of (2.97 ± 0.6) × 10–2 s–1 for mouse IgG/anti-mouse IgG. We demonstrate that the FOPPR biosensor can study real-time biomolecular interactions.