Development of protein microarrays and label-free microfluidic immunoassays

Abstract

Immunoassays are important analytical tools commonly used in life science and medical diagnosis to detect and quantify target proteins. However, currently available methods still suffer from long processing time, large sample volume and requirement for labeling. To address these issues, we first considered new methods to covalently immobilize protein microarrays on solid surfaces decorated with self-assembled monolayers to improve protein stability. In particular, we have developed simple methods of arranging proteins at different locations within a small surface area to form protein microarrays by using spontaneous formation of protein microarrays on surface with chemical micropatterns, and direct printing of protein micropatterns. Secondly, by exploiting the optical properties of liquid crystals (LCs), we successfully developed a label-free protein detection method which features a highly sensitive and interesting all-or-nothing optical output. More importantly, the optical signal can be observed with the naked eye directly without using any instrumentation. Finally, the LC-based detection method was integrated with microfluidic systems to develop a high throughput and miniaturized immunoassay. This new technology shows great promise for the development of a faster, more sensitive and portable immunoassays for point-of-care diagnostic applications.