Abstract
A portable and power-free microfluidic device was designed for rapid and sensitive detection of lead (Pb(2+)). 11-mercaptoundecanoic acid (MUA)-functionalized gold nanoparticles (MUA-AuNPs) aggregated in the presence of Pb(2+) for the chelation mechanism. When we performed this analysis on a polydimethylsiloxane (PDMS) microfluidic chip, the aggregations deposited onto the surface of chip and formed dark lines along the laminar flows in the zigzag microchannels. This visual result can be observed by the naked eye through a microscope or just a drop of water as a magnifier. Ten μM Pb(2+) was successfully detected.