Analytical characteristics and sensitivity mechanisms of electrolyte-insulator-semiconductor system-based chemical sensors?a critical review

Abstract

Recent trends in research and development of electrolyte-insulator-semiconductor (EIS) field-effect chemical sensors (ion-selective field-effect transistors, light-addressable potentiometric sensors, capacitive EIS-sensors) with inorganic gate insulators (oxide, nitride and chalcogenide films) are reviewed. Physical properties of EIS systems and basic mechanisms of their chemical sensitivity are examined. Analytical characteristics and sensing mechanisms of EIS pH sensors with oxide and nitride films, as well as metal ions sensors with chalcogenide films, are critically discussed. Prospects of future research on EIS field-effect biosensors are briefly outlined.

Potentiometric monitoring DNA hybridization

“…In field-effect devices, the change in the potential difference at the electrolyte-insulator interface is due to a change in the chemical composition of the analyte either because of ion exchange or the adsorption of ions. The traditional pH meter which uses a glass electrode is based on ion exchange, and the pH sensitivity of ion sensitive field-effect transistors (ISFETs) could be related to the characteristics of metal oxides (Vlasov et al, 2003). Another possible explanation for pH sensitivity is based on the site-dissociation-site-binding model of the electrolyte surface (Bergveld, 1996), which was originally developed and used in colloid chemistry.…”

Effect of O2 plasma on properties of electrolyte-insulator-semiconductor structures

“…In this case, the drift behavior can be also determined for sensor chips treated with O 2 plasma (270 mV/10 min), which is larger than that of the reference sensor chip without oxygen plasma treatment (4 mV/10 min). Slow drifts in such electrolyte‐SiO 2 Si system can also be related to both ions in‐diffusion and buried OH sites .…”

Chemical and Biological Field‐Effect Sensors for Liquids—A Status Report

“…Generally, the following basic mechanisms of potential generation can be considered: a pH or ion-concentration change, enzymatic reactions, adsorption of charged macromolecules (e.g., polyelectrolytes, deoxyribonucleic acid (DNA)), affinity binding of molecules (e.g., antigen-antibody affinity reaction, DNA hybridization), and potential changes that are coming from living biological systems as a result of more sophisticated (bio-)chemical processes (e.g., action potentials of nerve cells). [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] However, sometimes these results have been "rediscovered" from results that have already been obtained more than 10-30 years ago. At present, Si 3 N 4 , Al 2 O 3 , and Ta 2 O 5 serve as pH-sensitive gate insulator materials in commercial ISFETs.…”

“…Ta 2 O 5 is considered as the best pH-sensitive material for field-effect sensors, combining a practically ideal Nernstian pH sensitivity, minimal drift, and hysteresis. 5,6,13 In addition, as discussed in Section 4, it seems that Ta 2 O 5 is also the best corrosion-resistant pH-sensitive material.…”