Liquid crystal-based optical platform for the detection of colon and breast cancer cell lines using folic acid-conjugated gold nanoparticles

Abstract

In the present study, we report for the first time a liquid crystal-based biosensor for the highly sensitive and specific detection of colon and breast cancer cells using folic acid-conjugated gold nanoparticles (FA@GNPs) as the recognition element. FA@GNPs were immobilized on a glass substrate coated with N-dimethyl-N-octadecyl-3-aminopropyltrimethoxysilyl chloride (DMOAP), which induces homeotropic alignment of the liquid crystal molecules. Folate receptors, which are overexpressed in various cancer types, including colon and breast cancer cells, facilitate the selective binding of these cells to FA@GNPs. This binding event disrupts the vertical alignment of the liquid crystal molecules, causing a distinct transition from a dark to a bright state, which is observable via polarizing optical microscopy. Quantitative analysis of the cancer cells was performed by calculating the average grayscale intensity of the optical images, demonstrating that the proposed cell detection platform can sensitively detect individual cancer cells. The proposed liquid crystal biosensor utilizing FA@GNPs as the detection element offers a simple, cost-effective, label-free platform with exceptional specificity and sensitivity for early cancer detection. This novel approach holds significant potential for the development of advanced diagnostic tools in oncological research.