Functionalization of Oxide‐Free Silicon Surfaces for Biosensing Applications

Abstract

AbstractAs an alternative to standard silicon biofunctionalization protocol based on alkoxysilanes that bind to SiO2 on oxidized silicon substrates, several protocols to form bifunctional interlayers that directly bind to the silicon surface via a strong SiC bond have been developed during the last decades. These interlayers are more stable, and the lack of an insulating layer between the substrate and the interlayer reduces electric noise in biosensor devices. SiC monolayers are not yet regularly applied as the protocols are more complex and generally require an inert gas atmosphere. However, a variety of applications and new methods to form bifunctional SiC interlayers are recently developed. Here, the role these innovative protocols and interlayers play in biofunctionalization of silicon surfaces is reviewed and their applications in electrochemical, microelectromechanical, and optical biosensing are reported. From the analysis of the current situation, it can be concluded that the advantageous properties offered with this approach in many cases more than outweigh the additional processes to form SiC bonded interlayers and the approach is predicted to expand the applications of future silicon‐based biosensors.