Highly Sensitive Detection of Influenza A (H1N1) Virus With Silicon Nanonet BioFETs

Highly sensitive silicon-nanonet biologically active field-effect transistors (BioFETs) for the detection of influenza A (H1N1) virus have been demonstrated using a top-down process. The BioFETs show excellent intrinsic electrical characteristics, such as a low threshold voltage of 0.7 V and high on/off current ratio of ~10
⁷
. The sensing characteristics were measured at room temperature with various concentrations of H1N1 virus in a range of 10 pg/ml - 100 ng/ml. The current-related sensitivity (
${S}_{ {I}}$
) shows a higher value in the subthreshold regime, where
${S}_{ {I}}$
is strongly correlated with the subthreshold swing (
SS
). The voltage-related sensitivity (
${S}_{ {V}}$
) shows almost constant behavior from the subthreshold regime to the linear regime. The limit of detection (LOD) was 10 pg/ml, which is 6 times lower than values previously reported for FET-type sensors. In addition, the nanonet sensors exhibit high specificity to influenza A virus with negligible false positive for influenza B virus.