Abstract
A bioelectronic hybrid system for the detection of acetylcholine esterase (AChE) catalytic activity was assembled by way of immobilizing the enzyme to the gate surface of an ion-sensitive field-effect transistor (ISFET). Photometric methods used to characterize bonded enzyme and linker layers on silicon substrates confirm the existence of a stable amino-cyanurate containing AChE monolayer. The transduction of the enzyme-functionalized ISFET, in ionic solutions, is detected in response to application of acetylcholine (ACh). Recorded sensitivity of the modified ISFET to ACh has reached levels of up to 10-5 M. The Michaelis-Menten constant of the immobilized AChE is only moderately altered. Nevertheless, the maximum reaction velocity is reduced by over an order of magnitude. The ISFET response time to bath or ionophoretic application of ACh from a micropipette was in the range of a second. The catalytic activity of the immobilized AChE is inhibited in a reversible manner by eserine, a competitive inhibitor of AChE. We conclude that the immobilized enzyme maintains its pharmacological properties, and thus the described bioelectronic hybrid can serve as a detector for reagents that inhibit AChE activity.
Original language | English |
---|---|
Pages (from-to) | 605-612 |
Number of pages | 8 |
Journal | Biosensors and Bioelectronics |
Volume | 22 |
Issue number | 5 |
DOIs | |
State | Published - 15 Dec 2006 |
Bibliographical note
Funding Information:This study was supported by a grant from the Future and Emerging Technologies arm of the 5th IST Programme (No. IST-1999-29091). Parts of the study were carried out at the Charles E. Smith Family Laboratory for Collaborative Research in Psychobiology. The Neuro-Electronic research group of M.E.S., J.S. and S.Y. was established in 2000 by funding from the Israel Ministry of Science. Funding of this project was refused by the Israel Science Foundation. M.E. Spira is the Levi DeViali Professor in neurobiology.
Keywords
- Acetylcholine
- Acetylcholine antagonists
- Acetylcholine esterase
- Aplysia
- Biosensors