(676b) Development of Lspr-Based Biosensor for the Detection of Sjogren’s Syndrome Biomarkers

Authors: 
Murphy, A. C., The University of Texas at Austin
Wechsler, M. E., The University of Texas at Austin
Clegg, J. R., The University of Texas at Austin
Peppas, N. A., University of Texas at Austin
Sjogren’s syndrome (SS) is a chronic autoimmune disease that commonly manifests through oral and ocular dryness as a result of lymphocytic infiltration of the salivary and lacrimal glands. Patients with SS often go undiagnosed due to the lack of specific symptoms. Recently, there has been growing interest in using biomarkers in the saliva and lacrimal fluid to develop non-invasive tests for SS that can provide rapid and accurate feedback. Despite the promise that these methods hold, many potential biomarkers lack the specificity required, and patients with reduced lacrimal and salivary function may have difficulty producing enough fluid for quantitative measurement. For this reason, this work looks at the design and evaluation of utilizing the local refractive index sensitivity of the localized surface plasmon resonance (LSPR) of gold nanoshells (AuNS) for the detection of protein biomarkers expressed in patients with SS.

AuNS were prepared by seeded growth of colloidal gold on aminated silica nanoparticles and encapsulated by poly(maleic anhydride-alt-1-octadecene)-g-poly(ethylene glycol) methacrylate (PMAO-g-PEGMA) graft copolymer to improve particle stability. Transmission electron microscopy (TEM) was used to determine the size distribution. Then, the AuNS were incorporated into the aqueous phase of an inverse emulsion copolymerization of acrylamide and methacrylic acid, crosslinked with poly(ethylene glycol) dimethacrylate (PEGDMA), to form a polymer shell on the surface of AuNS that can be further modified by altering the composition and the PEGDMA chain length to affect the swelling of the polymer network. Additional comonomers with desirable functional groups can be introduced in order to tune the affinity for the target protein. For optimization of the sensor design, the impact of different substrate anchoring methods for the AuNS will be investigated. The AuNS density and the sensitivity of the LSPR response will be determined using TEM and UV-VIS spectroscopy, respectively and compared to the response of the functionalized AuNS in solution.

Work supported by National Institutes of Health Grant R01-EB022025