title: Minimizing nonspecific protein adsorption in liquid crystal immunoassays by using surfactants.
abstract: In this paper, we report the role of surfactants in minimizing nonspecific protein adsorption in liquid crystal (LC)-based immunoassays in which LC is used as a readout system. Among all surfactants tested, only nonionic surfactant such as Tween 20 can effectively reduce the nonspecific protein adsorption, while maintaining the selectivity of the LC-based immunoassay. We also show that to minimize nonspecific protein adsorption, Tween 20 can be added directly into the antibody solution to a final concentration of 0.8 mM. After the addition of Tween 20, better correlations between the antibody concentrations and the interference colors of LCs can therefore be obtained. For example, when Cy3 antibiotin was used, black, yellow, red, and green interference colors correspond to a concentration of 5, 25, 50, and 100 μg/mL, respectively. This feature gives LC immunoassay a unique advantage over the fluorescence-based immunoassay.
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore (117576).
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Woo Tien
authors.initials: WT
authors.lastname: Ang
authors.forename: Chang-Ying
authors.initials: CY
authors.lastname: Xue
authors.forename: Kun-Lin
authors.initials: KL
authors.lastname: Yang
mesh_terms: D000327:Adsorption; D000906:Antibodies / Q000276:immunology; D001710:Biotin / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D002232:Carbocyanines / Q000737:chemistry; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D007118:Immunoassay / Q000379:methods*; D050866:Liquid Crystals / Q000737:chemistry*; D046210:Microfluidic Analytical Techniques; D011136:Polysorbates / Q000737:chemistry; D011506:Proteins / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D000906:Antibodies; D002232:Carbocyanines; D004129:Dimethylpolysiloxanes; D011136:Polysorbates; D011506:Proteins; D013501:Surface-Active Agents; C089187:cyanine dye 3; C013830:baysilon; D001710:Biotin