Towards in vivo biosensors for low-cost protein sensing

• Published in: Electronics letters 2013-03, Vol.49 (7), p.450-451
• Main Authors: Ramesh, A, Ren, F, Berger, P.R, Casal, P, Theiss, A, Gupta, S, Lee, S.C
• Format: Article
• Language: English
• Subjects: Al2O3 capacitors; alkali ion dose; alkali ion penetration; biochemistry; Biological and medical sciences; Biomedical technology; Biosensors; Biotechnology; detectable alkali ions; elemental semiconductors; Fundamental and applied biological sciences. Psychology; gate dielectric; high‐salt concentration bodily fluids; impermeability; in vivo biosensors; metal oxide semiconductor capacitor; metal‐oxide‐semiconductor; Methods. Procedures. Technologies; mobile alkali ions; molecular biophysics; MOS capacitors; nanoelectronics; nanofabrication; PBS solution; permeability; protein sensing; proteins; silicon compounds; silicon dioxide MOS capacitors; SiO2; size; size 100 nm to 10 nm; sterile physiological buffer solution; threshold voltage; transistor operation; transistors; triangular voltage sweep technique; Various methods and equipments
• ISSN: 0013-5194; 1350-911X; 1350-911X
• DOI: 10.1049/el.2012.4283

In vivo biosensing requires stable transistor operation in high-salt concentration bodily fluids while exhibiting impermeability to mobile alkali ions that would otherwise render the metal-oxide-semiconductor (MOS) threshold voltage to drift. Metal oxide semiconductor capacitor structures using Al2O3 as the gate dielectric were soaked in a sterile physiological buffer solution (PBS) up to 24 hours and for thicknesses from 100 to 10 nm. The triangular voltage sweep technique characterised alkali ion penetration, and measured no detectable alkali ions for the Al2O3 capacitors. By contrast, the dose of alkali ions in silicon dioxide MOS capacitors steadily increased with increasing soak times in the PBS solution.