Editing Nanowire (section)

==== Limitations of sensing with [[silicon nanowire]] FET devices ====
Generally, the charges on dissolved molecules and macromolecules are screened by dissolved counterions, since in most cases molecules bound to the devices are separated from the sensor surface by approximately 2–12&nbsp;nm (the size of the receptor proteins or DNA linkers bound to the sensor surface). As a result of the screening, the electrostatic potential that arises from charges on the analyte molecule decays exponentially toward zero with distance. Thus, for optimal sensing, the [[Debye length]] must be carefully selected for nanowire FET measurements.
One approach of overcoming this limitation employs fragmentation of the antibody-capturing units and control over surface receptor density, allowing more intimate binding to the nanowire of the target protein. This approach proved useful for dramatically enhancing the sensitivity of [[Cardiac marker|cardiac biomarkers]] (e.g. [[Troponin]]) detection directly from serum for the diagnosis of acute myocardial infarction.<ref>{{cite journal|last=Elnathan|first=Roey |author2=Kwiat, M. |author3=Pevzner, A. |author4=Engel, Y. |author5=Burstein, L. |author6=Khatchtourints, A. |author7=Lichtenstein, A. |author8=Kantaev, R. |author9=Patolsky, F.|title=Biorecognition Layer Engineering: Overcoming Screening Limitations of Nanowire-Based FET Devices|journal=Nano Letters|date=10 September 2012|volume=12|issue=10|pages=5245–5254|doi=10.1021/nl302434w|pmid=22963381|bibcode=2012NanoL..12.5245E }}</ref>