Performance of Eudragit coated whispering gallery mode resonator-based immunosensors

Abstract

Whispering gallery mode resonators (WGMR) are an efficient tool for the realization of optical biosensors. A high Q factor preservation is a crucial requirement for good biosensor performances. In this work we present an Eudragit®L100 coated microspherical WGMR as an efficient immunosensor. The developed resonator was morphologically characterized using fluorescence microscopy. The functionalization process was tuned to preserve the high Q factor of the resonator. The protein binding assay was optically characterized in terms of specificity in buffer solution.

Figure 1.

A schematic diagram of the experimental arrangement.

Figure 2.

Fluorescent image of the sample anti-mouse-IgG.

Figure 3.

Measured Q factor of the NT sample (black line), of a covalent binding of IgG (blue line) and an IgG/anti-IgG interaction (red line).

Figure 4.

Sensorgram of anti-IgG binding to a WGMR immobilized with IgG in PBS, following the addition of anti-IgG.