Comparison of Different Protein Immobilization Methods on Quartz Crystal Microbalance Surface in Flow Injection Immunoassay
✍ Scribed by Yung-Chuan Liu; Chih-Ming Wang; Kuang-Pin Hsiung
- Publisher
- Elsevier Science
- Year
- 2001
- Tongue
- English
- Weight
- 96 KB
- Volume
- 299
- Category
- Article
- ISSN
- 0003-2697
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✦ Synopsis
In this study, a quartz crystal microbalance (QCM) system operated repetitively in flow injection analysis (FIA) mode, is reported. Four immobilization approaches of seven different methods include: (i) physical adsorption; (ii) two thioamine thiolation methods, using cysteamine and cystamine for gold chemisorption and further coupling; (iii) two oxidized dextran spacer methods, coupling of cysteamine and cystamine thiolated QCM surface with periodate-oxidized dextran for further Schiff acid-base reaction; and (iv) two thiol-gold chemisorption-based self-assembled monolayer (SAM), applying short-chain, C(3), and long-chain, C(11), mercapto fatty acids to insolubilize human serum albumin (HSA) on QCM surface. Effects of these protein immobilization methods on FIA immunoassay of anti-HSA were compared. At the 0.01 mg/ml anti-HSA level, the lowest analyte concentration tested, the SAM using 11-mercaptoundecanoic acid as QCM surface activating agent generated a larger frequency shift than the other immobilization methods. This implied that the use of thiolated long-chain fatty acid constructed as self-assembled monolayer may thereby potentially be a useful protein immobilization method in QCM-FIA application.