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Electrostatic Limit of Detection of Nanowire‐Based Sensors
Author(s) -
Henning Alex,
Molotskii Michel,
Swaminathan Nandhini,
Vaknin Yonathan,
Godkin Andrey,
Shalev Gil,
Rosenwaks Yossi
Publication year - 2015
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201500566
Subject(s) - nanowire , detection limit , materials science , field effect transistor , transistor , optoelectronics , biasing , electric field , nanotechnology , analytical chemistry (journal) , voltage , chemistry , physics , chromatography , quantum mechanics
Scanning gate microscopy is used to determine the electrostatic limit of detection (LOD) of a nanowire (NW) based chemical sensor with a precision of sub‐elementary charge. The presented method is validated with an electrostatically formed NW whose active area and shape are tunable by biasing a multiple gate field‐effect transistor (FET). By using the tip of an atomic force microscope (AFM) as a local top gate, the field effect of adsorbed molecules is emulated. The tip induced charge is quantified with an analytical electrostatic model and it is shown that the NW sensor is sensitive to about an elementary charge and that the measurements with the AFM tip are in agreement with sensing of ethanol vapor. This method is applicable to any FET‐based chemical and biological sensor, provides a means to predict the absolute sensor performance limit, and suggests a standardized way to compare LODs and sensitivities of various sensors.