Exploring optical properties of liquid crystals for developing label-free and high-throughput microfluidic immunoassays

Abstract

A liquid crystals (LC)-based detecting method suitable for microfluidic immunoassays was successfully demonstrated in the study. The microfluidic device comprised three serpentine channels supported on an immunoglobulin (IgG)-coated glass slides and sealed with poly(dimethylsiloxane) (PDMS) with embedded microfluidic channels. Two fluorescence-labeled antibody solutions, fluorescein-isothiocyanate-conjugated anti-human IgG (FITC-anti0IgG) and FITC-conjugated anti-biotin IgG (FITC-anti-biotin), were then piped into the inlet reservoirs of two separate channels, allowing both solutions to enter the microfluidic channels by capillary actions. After 30 minutes, the slides were rinsed with PBS buffer with 1% SDS and deionized water. It was demonstrated that LC-based detection and microfluidic immunoassays provide a label-free, multiplexed and high-throughput diagnostic platform, which can be used to detect multiple samples of anti-IgG, anti-biotin and mixture of both.