(700c) Multiplexed Detection of Protein Biomarkers Using Recognitive Polymers in a Localized Surface Plasmon Resonance Sensor Array
Crosslinked copolymers of N-isopropylacrylamide (NIPAM) and methacrylic acid (MAA) (poly(NIPAM-co-MAA)) were synthesized on surface modified AuNSs via precipitation polymerization. After synthesis, additional functional groups were introduced into the polymer shell via post-synthesis modifications to generate a set of polymers with varied recognition properties. Absorbance spectra were measured to detect the LSPR response of each polymer-AuNS composite to increasing concentrations of protein biomarkers. Bare AuNSs showed negligible LSPR shifts upon incubation with any protein. On the other hand, recognitive polymer coated AuNSs exhibited concentration dependent red-shifts in LSPR wavelength upon incubation with proteins for which the polymer had a high binding affinity, but no shifts were observed for low affinity polymer-protein combinations. The polymer-AuNS composites that exhibited the most distinctive recognition profiles were combined in a sensor array that enables multiplexed detection of SjÃ¶grenâ??s syndrome biomarkers.