TUD

Smart combination of nanosensors and droplets based reactors represents a powerful tool for monitoring and high throughput analysis of the kinetics of biological and chemical reactions, staying miniaturized, highly sensitive and optically label-free. Here we present a first demonstration of droplets microfluidics with the compact silicon nanowire field effect transistor (SiNW FET) on a single chip for in flow electrical detection of aqueous reactor-drops. Apart from detection events, we chemically probe the content of numerous droplets in a row as independent events (up to ten thousands), and resolve the pH values and ionic strength of the solution, resulted in a change of a source-drain current through the nanowires. Optic-less and noninvasive measurements of these parameters in aqueous droplets have a great impact on the area of biodetection and bioanalytics as a high throughput screening tool for pathogens, drug assays, and evaluation of the enzymatic activities.