title: H+ISFET-based biosensor for determination of penicillin G.
abstract: A biosensor based on an H+ ion sensitive field effect transistor (H+(-)ISFET) and penicillin G acylase has been developed. The response time of the sensor to different concentrations of penicillin G was 30 s. In a 20 mM phosphate buffer at pH 7.0, the linear range of the calibration curve was from 0.5 to 8 mM. The coefficients of variation for three samples with 20 repeated measurements were below 5%. Stability of the sensor could reach about 6 months and more than 1000 runs were performed without a significant decrease of the output value. The sensor was tested for measurement of the penicillin G content in penicillin fermentation both. Forty samples with low and high concentrations of penicillin G were chosen for the correlation test. The values assayed by the sensor method were compared with the values assayed by HPLC method, the correlation coefficient (r) was 0.9944 and the regression equation was y = 1.034X - 2083.7, respectively. The different measuring methods are discussed in the text.
authors.affiliation: Institute of Microbiology, Academia Sinica, Beijing, People's Republic of China.
authors.forename: J
authors.initials: J
authors.lastname: Liu
authors.forename: L
authors.initials: L
authors.lastname: Liang
authors.forename: G
authors.initials: G
authors.lastname: Li
authors.forename: R
authors.initials: R
authors.lastname: Han
authors.forename: K
authors.initials: K
authors.lastname: Chen
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000706:statistics & numerical data; D002021:Buffers; D005069:Evaluation Studies as Topic; D006863:Hydrogen-Ion Concentration; D010399:Penicillin Amidase; D010400:Penicillin G / Q000032:analysis*; D011522:Protons; D015203:Reproducibility of Results; D014173:Transistors, Electronic
chemical_list: D002021:Buffers; D011522:Protons; D010399:Penicillin Amidase; D010400:Penicillin G