Fabrication of silicon BioCHIPs with charge pattern and surface-near electrostatic forces

The selective attachment of molecular or cellular biological elements on flat substrates plays a critical role towards advancements in the field of biotechnology. As majority of the available market for biotech products (e.g. biosensors) is based on the functionalization of substrates, new approaches offering carriers with superior performance i.e. with easy-to-control immobilization of the target bio-elements are desirable. Though, many fabulous developments have been witnessed over the past decades, the controlled entrapment of biomolecules remains an unsolved problem. The frequently utilized routes of chemical-covalent or biological immobilization suffer from limited control and tendency to deactivate. Consequently, new carrier designs with alternative mechanisms of entrapment are of considerable interest. Following this trend, herein we present a promising concept for selective biomolecule assembly onto the bulk-functionalized PolCarr-BioChip. PolCarr-BioChip consists of a doped Si-wafer with an ultra-thin insulating film and a characteristic patter of surface near electrostatic forces (SNEF). The binding of the electrically polarizable bio-element onto PolCarr is purely driven by SNEF, offering an excellent degree of control on the mm-µm-nm scale. By varying the doping conditions, the SNEF can be readily altered. This, in turn, allows for optimization of binding efficacy of the PolCarr-BioChip. Finally, the design of PolCarr can be adjusted to the individual target application (e.g. directed nerve cell growth). The examples of the application-tailored PolCarr templates will be demonstrated in the presentation. We believe the unique features of the PolCarr-BioChip make it a promising alternative to the challenges faced by variety of state-of-the-art biotech products.