Miniaturized amperometric flow immunoassay system using a glass fiber membrane modified with anion

• Published in: Biotechnology and bioengineering Vol. 77; no. 7; pp. 758 - 763
• Main Authors: Lim, Tae-Kyu, Imai, Satoko, Matsunaga, Tadashi
• Format: Journal Article
• Language: English
• Published: New York Wiley Subscription Services, Inc., A Wiley Company 30.03.2002; Wiley
• Subjects: Animals; Antibodies, Monoclonal; Antigen-Antibody Complex - analysis; Biological and medical sciences; Biosensing Techniques - instrumentation; Biosensing Techniques - methods; Biotechnology; Cattle; Chorionic Gonadotropin - analysis; Chromatography, Ion Exchange - instrumentation; Electrochemistry - methods; ferrocene-conjugated IgG; Ferrous Compounds - chemistry; Flow Injection Analysis - instrumentation; Flow Injection Analysis - methods; Fundamental and applied biological sciences. Psychology; Glass - chemistry; glass fiber membrane; human chorionic gonadotrophin; Humans; Immunoassay - instrumentation; Immunoassay - methods; Immunoglobulin G - chemistry; Isoelectric Focusing - methods; Membranes - chemistry; Methods. Procedures. Technologies; miniaturized amperometric flow immunoassay; Others; Serum Albumin, Bovine - analysis; Time Factors; Various methods and equipments; Human; Chemical modification; Analysis method; Amperometry; Chorionic gonadotrophin; Membrane; Miniaturization; Glass fiber; Medical application; Quantitative analysis; Immunological method
• ISSN: 0006-3592; 1097-0290
• DOI: 10.1002/bit.10158

This paper describes a miniaturized amperometric flow immunoassay system using a glass fiber membrane modified with anion. The glass fiber membrane was functionally modified with γ‐glycidoxypropyltrimethoxysilane and sodium thiosulfate and was used for separation of protein. Anti‐human chorionic gonadotrophin (HCG) immunoglobulin G (IgG) antibody conjugated with ferrocenemonocarboxylic acid (Fc), namely, Fc‐conjugated IgG (Fc–IgG), was used as a novel analytical reagent. HCG and Fc–IgG complexes were separated from free Fc–IgG based on differences in isoelectric point (pI) using the glass fiber membrane modified with a thiosulfonyl acid functional group. The assay yields a linear relationship between current and HCG concentration in the range of 0–2000 mIU/mL. This simple technique enables the assay of HCG within 2 min. The modified glass fiber membrane was regenerated by occasional elution with malonate buffer (pH 6.0) containing 0.5 M NaCl, to remove free Fc–IgG. Free Fc–IgG recovered in this manner could be reused up to eight times without significant decreases in sensitivity. This miniaturized amperometric flow immunoassay requires only minute quantities of serum and generates highly reproducible results. © 2002 John Wiley & Sons, Inc. Biotechnol Bioeng 77: 758–763, 2002; DOI 10.1002/bit.10158