MEMS-based gas chromatography columns with nano-structured stationary phases

Gas chromatography columns produced using microelectromechanical systems (MEMS) technology makes it possible to achieve very narrow widths as it improves the separation efficiency. However, coating these columns to obtain a uniform stationary phase is challenging using traditional techniques. This paper presents an important step to address this issue by merging MEMS and nanotechnology and reports, for the first time, MEMS-based columns coated with functionalized gold nanoparticles (FGNPs) by a modified layer-by-layer (LbL) deposition technique. The FGNPs were made stable by coating the etched silicon surface with a thin layer of silicon nitride. These films are of particular interest for GC as they provide a homogeneous phase with nanometer resolution and a fast mass transfer rate. The 1 m-long MEMS column with FGNP stationary phase was successful in separating a mixture of 6 alkanes in less than 6 minutes.