Efficient thermal lens nanoparticle detection in a flow-focusing microfluidic device

A flow-focusing microfluidic device was fabricated for thermal lens nanoparticle detection. In this device, sample flow was first sandwiched by lateral z-axis sheath flows, and then by horizontal xy-plane sheath flows. The three-dimensional flow focus was visualized using an aqueous dye solution. Subsequently, 500-nm-sized red polystyrene particles were individually detected by the thermal lens detection method. When 1 mu L of sample solution containing 300 particles/mu Lwas passed through the thermal lens detection point, 255 +/-+ 20 peaks corresponding to particles were observed. (C) 2016 Elsevier B.V. All rights reserved.