University of North Florida
Browse the Citations
-OR-

Contact Info

Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Email: schalk@unf.edu
Website: @unf

View Stuart Chalk's profile on LinkedIn

Masuo Aizawa

Abbrev:
Aizawa, M.
Other Names:
Address:
Department of Biological Information, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama 226-5801, Japan
Phone:
+81-45-924-5759
Fax:
+81-45-924-5779

Citations 3

"Flow Injection Analytical System For Glucose With Screen-printed Enzyme Biosensor Incorporating Os-complex Mediator"
Anal. Chim. Acta 2001 Volume 426, Issue 1 Pages 33-41
Chengxiao Zhang, Qiang Gao and Masuo Aizawa

Abstract: A novel flow injection analytical system with a screen-printed enzyme sensor incorporating Os-complex mediator has been developed. A newly created glucose biosensor was fabricated using thick-film technique and co-immobilization of glucose oxidase and Os-complex on a permeable membrane. The composition of the enzyme and mediator in the membrane and the analytical conditions were optimized. The flow injection electrochemical system showed that glucose was detected linearly in the concentration range from 0.1 to 10 mM with a detection limit of 0.03 mM by 50 µl of sample injection, giving a throughout of about 40 samples per hour. The glucose biosensors retained their constant response after more than 100 injections and storage over a month. The designed electrochemical flow system with a disposable biosensor is suitable for automatic and rapid determination of glucose.
Glucose

"4-Hydroxynaphthyl-1-phosphate As A Substrate For Alkaline Phosphatase And Its Use In Sandwich Immunoassay"
Anal. Chim. Acta 1999 Volume 402, Issue 1-2 Pages 29-35
Már Másson, Tetsuya Haruyama, Eiry Kobatake and Masuo Aizawa

Abstract: The synthesis and the use of a new substrate, 4-hydroxy-naphthyl-1-phosphate (HNP), for the amperometric detection of alkaline phosphatase activity is described. The product of the enzymatic hydrolysis of HNP was dihydroxy naphthalene (DHN). DHN was rapidly oxidized in air to give naphthoquinone (NQ), which was measured in amperometric flow injection analysis (AFIA) at 300 mV versus Ag/AgCl. DHN standards could be measured at a 60 nM detection limit. There was a linear response to the enzyme with a 300 fM detection limit, which was equivalent to 6 attomole for each injection. The measurement range for human IgG, in an alkaline phosphatase amplified sandwich immunoassay with amperometric, was 1-1000 ng/ml.
Detection limit

"Immunosensing With Amperometric Detection, Using Galactosidase As Label And P-aminophenyl-galactopyranoside As Substrate"
Anal. Chim. Acta 1995 Volume 304, Issue 3 Pages 353-359
Már Mássen, Zheng Liu, Tetsuya Haruyama, Eiry Kobatake, Yoshihito Ikariyama and Masuo Aizawa*

Abstract: p-Aminophenyl---galactopyranoside (PAPG) was shown to be a suitable substrate for the amperometric detection of galactosidase activity at neutral pH. The application of this amplification system for immunoassay was demonstrated. The product of the enzyme reaction, p-aminophenol (PAP), was detected at 200 mV, vs. , by flow-injection analysis (FIA), with a 50 nM detection limit. PAPG was hydrolyzed more than 2.5 times faster than p-nitrophenyl---galactopyranoside, by the enzyme. Both PAP and PAPG were stable at pH 7. The galactosidase concentration could be measured down to a concentration of 100 fM, and mouse IgG could be assayed by sandwich immunoassay down to 700 fM. PAPG was found to be a promising reagent for heterogeneous systems, like the one described, and for homogeneous assays of biological fluids.
Enzyme, galactosidase Biological fluid Immunoassay Amperometry Enzyme Amplification reaction