title: Enhanced sensing of nucleic acids with silicon nanowire field effect transistor biosensors.
abstract: Silicon nanowire (SiNW) field effect transistors (FETs) have emerged as powerful sensors for ultrasensitive, direct electrical readout, and label-free biological/chemical detection. The sensing mechanism of SiNW-FET can be understood in terms of the change in charge density at the SiNW surface after hybridization. So far, there have been limited systematic studies on fundamental factors related to device sensitivity to further make clear the overall effect on sensing sensitivity. Here, we present an analytical result for our triangle cross-section wire for predicting the sensitivity of nanowire surface-charge sensors. It was confirmed through sensing experiments that the back-gated SiNW-FET sensor had the highest percentage current response in the subthreshold regime and the sensor performance could be optimized in low buffer ionic strength and at moderate probe concentration. The optimized SiNW-FET nanosensor revealed ultrahigh sensitivity for rapid and reliable detection of target DNA with a detection limit of 0.1 fM and high specificity for single-nucleotide polymorphism discrimination. In our work, enhanced sensing of biological species by optimization of operating parameters and fundamental understanding for SiNW FET detection limit was obtained.
authors.affiliation: State Key Laboratories of Transducer Technology and Science and Technology on Micro-system Laboratory, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050, China.
authors.forename: Anran
authors.initials: A
authors.lastname: Gao
authors.forename: Na
authors.initials: N
authors.lastname: Lu
authors.forename: Yuchen
authors.initials: Y
authors.lastname: Wang
authors.forename: Pengfei
authors.initials: P
authors.lastname: Dai
authors.forename: Tie
authors.initials: T
authors.lastname: Li
authors.forename: Xiuli
authors.initials: X
authors.lastname: Gao
authors.forename: Yuelin
authors.initials: Y
authors.lastname: Wang
authors.forename: Chunhai
authors.initials: C
authors.lastname: Fan
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D015342:DNA Probes / Q000737:chemistry / Q000235:genetics; D036103:Nanotechnology; D053770:Nanowires; D009693:Nucleic Acid Hybridization; D009696:Nucleic Acids / Q000032:analysis*; D009994:Osmolar Concentration; D012825:Silicon; D055672:Static Electricity; D014173:Transistors, Electronic
chemical_list: D015342:DNA Probes; D009696:Nucleic Acids; D012825:Silicon