Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7147213 | Sensors and Actuators B: Chemical | 2014 | 6 Pages |
Abstract
We utilized localized Joule heating to ablate methoxy-poly (ethylene-glycol)-silane (mPEG-sil) modified on the pâ region of an n+-pâ-n+ silicon nanobelt field-effect transistor (SNFET). SNFETs with selective modifications of 3-aminopropyltrimethoxysilane (APTMS) and NHS-biotin on the ablated region exhibited a faster sensing response rate and a higher sensitivity in real-time detection of Streptavidin (SA). Characterization of the ablated region via lateral force microscopy and the fluorescence image show that the ablation region occurs only in the pâ region near the drain side and is believed to be a result of the impact ionization mechanism during Joule heating. Moreover, a bias of 20Â V pulse voltage for 1Â ms successfully ablates mPEG-sil and reduces the device off leakage current by 1 order after Joule heating. However, Joule heating with a pulse voltage larger than 20Â V (1Â ms) yielded an increase of device off leakage owing to damage to gate dielectrics during Joule heating. A comparison of real-time detection of SA between selectively and non-selectively modified chips shows that selectively modified ones exhibit a better limit of detection (LOD) that is one order lower than non-selectively modified ones, and a sensing response rate twice as fast as the non-selectively modified one for every target concentration.
Keywords
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Hao Heng Liu, Tzung Han Lin, Jeng-Tzong Sheu,