Silicon nanowires as field-effect transducers for biosensor development: a review.
The unique electronic properties and miniaturized dimensions of silicon nanowires (SiNWs) are attractive for label-free, real-time and sensitive detection of biomolecules. Sensors based on SiNWs operate as field effect transistors (FETs) and can be fabricated either by top-down or bottom-up approaches. Advances in fabrication methods have allowed for the control of physicochemical and electronic properties of SiNWs, providing opportunity for interfacing of SiNW-FET probes with intracellular environments. The Debye screening length is an important consideration that determines the performance and detection limits of SiNW-FET sensors, especially at physiologically relevant conditions of ionic strength (>100mM). In this review, we discuss the construction and application of SiNW-FET sensors for detection of ions, nucleic acids and protein markers. Advantages and disadvantages of the top-down and bottom-up approaches for synthesis of SiNWs are discussed. An overview of various methods for surface functionalization of SiNWs for immobilization of selective chemistry is provided in the context of impact on the analytical performance of SiNW-FET sensors. In addition to in vitro examples, an overview of the progress of use of SiNW-FET sensors for ex vivo studies is also presented. This review concludes with a discussion of the future prospects of SiNW-FET sensors.
Chemical Sensors Group, Department of Chemical and Physical Sciences, University of Toronto Mississauga, 3359 Mississauga Road North, Mississauga, ON L5L 1C6, Canada.
M Omair
MO
Noor
Chemical Sensors Group, Department of Chemical and Physical Sciences, University of Toronto Mississauga, 3359 Mississauga Road North, Mississauga, ON L5L 1C6, Canada. Electronic address: ulrich.krull@utoronto.ca.
Ulrich J
UJ
Krull
D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D053770:Nanowires / Q000737:chemistry*; D012825:Silicon / Q000737:chemistry*; D013499:Surface Properties; D014159:Transducers
D012825:Silicon
Debye length; Field effect transistors; Gating; Silicon nanowires; Surface functionalization