TECHNICAL DESCRIPTION

The invention concerns a microfabricated device for the selective detection of lead, especially in water, by a fluorescence method. The microchip-based lead sensor contains a Y-shape microchannel equipped with a passive mixer and moulded in a silicone polymer (PDMS) stuck on a glass substrate. One input is used to inject the water sample and the other input for the sensitive fluorescent probe. An optimization of the microcircuit length has been performed in order to have a full complexation of lead by the fluorescent probe (calix-DANS4). The detection is performed by using a configuration in which the sensing molecules are excited by two optical fibres, each one connected to a 365 nm UV LED, and the light collection is made by another optical fibre with a photodetector. By using this configuration, it is possible to detect lead with a detection limit of 2 ppb.

A publication is existing : « Fluorimetric lead detection in a microfluidic device », Liyun ZHAO et al, Lab on a Chip, 2009, 9, 2818-2823.