Evolution of Materials in Novel Point-of-Care Diagnostics.

Abstract

Featured Articles: Sia SK, Whitesides GM. Microfluidic devices fabricated in poly (dimethylsiloxane) for biological studies. Electrophoresis 2003;24:3563–762; Chin C, Laksanasopin T, Cheung YK, Steinmiller D, Linder V, Parsa H, et al. Microfluidics-based diagnostics of infectious diseases in developing world. Nature Med 2011;17:1015–9.3 Because clinical laboratory diagnostic procedures involve repeated steps of manipulating fluid samples and chemical reagents, compact fluid handling lies at the heart of novel point-of-care (POC)4 diagnostic devices. Historically, POC devices such as glucometers and pregnancy tests have relied on capillary forces to drive the flow of fluids in paper-based membranes. Although simple, this method of fluid handling enables only a small number of mixing steps (typically 1 or 2, such as the solubilization of dried gold-conjugated antibodies by blood). In the 1990s, a simple new procedure called rapid prototyping could produce micron-sized features, such as open channels (within a solid substrate) through which fluids could move. Once a master mold was made in a dust-free clean room, replica structures could be repeatedly molded in polydimethylsiloxane (PDMS), a transparent rubber-like material used previously in industrial applications, such as a lubricant for …