The gate surface of an ion-sensitive field effect transistor (ISFET) was covered with a penicillinase-adsorbed Langmuir-Blodgett (LB) membrane in order to examine the potentiometric response to H+ ion and penicillin G. The LB membrane-modified ISFET exhibited pH response of —30 —40 mV/pH, whereas near-Nernstian response was obserbed for the ISFET without LB membrane. The ISFET penicillin sensor showed the potentiometric response to penicillin G at milimolar level in 5 mM phosphate buffer. The penicillin sensor could be used to determine penicillin G for more than 12 days without any deterioration.
- Langmuir-Blodgett membrane
- ion-sensitive field effect transistor
- penicillin sensor
ASJC Scopus subject areas
- Analytical Chemistry