Retention of copper(II) metal ions in a silicon-glass microfluidic device

Abstract

This work describes the construction of a silicon microchip for retention of copper(II) metal ions. Conventional photolithographic process was applied to transfer the generated pattern to silicon wafers. Using Reactive Ion Etching (RIE), SF6 based, channels 50 μm wide and 10 μm deep were produced. The channels were sealed with borosilicate glass using anodic bonding process. The surface of the channels were modified with N-(β-aminoethyl)- γ-aminopropyltrimetoxysilane through a silanization reaction to promote the adsorption of copper(II) ions. An amperometric detector was placed at the microchip outlet and copper(II) ions were detected by a gold electrode at 0 V (against Ag/AgCl(KCl sat.) reference electrode). Copper(II) ions were retained and eluted with HCl 50 μmol L-1 in a micro-flow system at a flow rate about 100 μL min-1. Reproducibility in the peak area and height were about 4.6 % and 10 %, respectively, for three consecutive injections of 600 μL of 10 μmol L-1 copper(II) sample. ©2007 Sociedade Brasileira de Química.