Semiconductor Biosensors [and Discussion]
1987 (English)In: Philosophical Transactions of the Royal Society of London. Biological Sciences, ISSN 0962-8436, Vol. 316, no 1176, 47-60 p.Article in journal (Refereed) Published
Hydrogen- and ammonia-sensitive metal-oxide semiconductor (MOS) structures are described. Special attention is paid to ammonia-sensitive MOS devices with thin (ca. 3 nm) iridium or platinum gates. It is shown how these devices can be used in combination with immobilized enzymes to develop bioprobes or biosensing systems. The temperature dependence of the gas sensitivity of MOS structures with catalytic metal gates is considered. It is demonstrated that at low temperatures (30-40 <latex>$^\circ$</latex>C)iridium gates have a faster response to ammonia than platinum gates, and that Ir-MOS structures thus are better suited for the development of biosensors. It is also shown that at high temperatures (190-200 <latex>$^\circ$</latex>C) platinum gates can be used to detect unsaturated hydrocarbons such as ethylene. Gas evolution from ripening fruits was monitored with such a sensor. Some biosensing applications of ammonia sensitive Ir-gate MOS devices are described; for example, the determination of urea and creatinine. The devices are used both to measure a pulse of ammonia in a flowthrough system and to measure in situ steady-state responses as a bioprobe. The special features of gas sensors used for biosensing purposes are summarized.
Place, publisher, year, edition, pages
Royal Society , 1987. Vol. 316, no 1176, 47-60 p.
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-88161DOI: 10.1098/rstb.1987.0016ISI: A1987J970100004OAI: oai:DiVA.org:liu-88161DiVA: diva2:601835