Enzyme sensors based on an ion-sensitive field effect transistor coated with Langmuir-Blodgett membranes. Use of polyethyleneimine as a spacer for immobilizing alpha-chymotrypsin.
A highly branched polyethyleneimine (PEI) was used as a spacer for immobilizing alpha-chymotrypsin on the surface of Langmuir-Blodgett (LB) membranes which were deposited on the gate of an ion-sensitive field effect transistor (ISFET). alpha-Chymotrypsin could be covalently immobilized through the glutaraldehyde-activated PEI on the LB membrane-coated ISFET. The alpha-chymotrypsin-modified ISFET showed a potentiometric response to the substrate at concentrations of more than 0.1 mM. Some performance characteristics of the sensor, such as pH response, response time, and long-term stability were examined.
Anzai
J
J
Lee
S
S
Osa
T
T
D002918:Chymotrypsin; D004566:Electrodes; D004798:Enzymes / Q000032:analysis*; D004800:Enzymes, Immobilized; D008567:Membranes, Artificial; D011094:Polyethyleneimine; D011199:Potentiometry; D014173:Transistors, Electronic
D004798:Enzymes; D004800:Enzymes, Immobilized; D008567:Membranes, Artificial; D011094:Polyethyleneimine; D002918:Chymotrypsin