A multipurpose capacitive biosensor for assay and quality control of human immunoglobulin G

Mahmoud Labib, Martin Hedström, Magdy Amin, Bo Mattiasson*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

31 Scopus citations

Abstract

We report a flow-injection biosensor system with a capacitive transducer for assay and quality control of human immunoglobulin G (hIgG). The sensing platform is based on self-assembled monolayers (SAMs) of carboxylic acid terminated alkyl-thiols with covalently attached concanavalin A. The electrochemical characteristics of the sensor surface were assessed by cyclic voltammetry using a permeable redox couple (potassium ferricyanide). The developed biosensor proved capable of performing a sensitive label-free assay of hIgG with a detection limit of 1.0 μg mL-1. The capacitance response depended linearly on hIgG concentration over the range from 5.0 to 100 μg mL-1, in a logarithmic plot. Typical measurements were performed in 15 min and up to 18 successive assays were achieved without significant loss of sensitivity using a single electrode. In addition, the biosensor can detect hIgG aggregates with concentrations as low as 0.01% of the total hIgG content (5.0 μg mL-1). Hence, it represents a potential post-size-exclusion chromatography-UV (post-SEC-UV) binding assay for in-process quality control of hIgG, which cannot be detected by SEC-UV singly at concentrations below 0.3% of the total hIgG content.

Original languageEnglish (US)
Pages (from-to)312-320
Number of pages9
JournalBiotechnology and Bioengineering
Volume104
Issue number2
DOIs
StatePublished - Oct 1 2009
Externally publishedYes

Keywords

  • Biosensor
  • Capacitance
  • Concanavalin A
  • Flow injection
  • Human immunoglobulin G
  • Quality control

ASJC Scopus subject areas

  • Biotechnology
  • Bioengineering
  • Applied Microbiology and Biotechnology

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