Novel renewable immunosensors based on temperature-sensitive PNIPAAm bioconjugates

Biosens Bioelectron. 2008 Dec 1;24(4):710-5. doi: 10.1016/j.bios.2008.06.041. Epub 2008 Jul 6.

Abstract

A novel renewable immunosensor was created comprising a temperature-controlled surface composed of poly(n-isopropylacrylamide) (PNIPAAm)-antibody conjugates that could reversibly bind the antigen. Bovine serum albumin (BSA) and the corresponding antibody (anti-BSA) were chosen as a model antibody-antigen system to demonstrate the concept. The thermally responsive PNIPAAm conjugated to anti-BSA displayed a controllable conformation change between an expanded and a collapsed form, below and above its characteristic phase transition temperature, i.e. low critical solution temperature (LCST). This showed a remarkable change in the bioaffinity of the conjugate for BSA. Thus, a renewable anti-BSA surface was generated for re-binding of the target antigen at the thermally controllable PNIPAAm-anti-BSA conjugated surface. The temperature-controlling strategy resulted in the regeneration of immunosensors on which immobilized anti-BSA antibodies retained their activity and specificity for more than 30 reproducible assays. The level of dissociation reached 89%, which is comparable with established recovery methods, while offering easer handing. The controlled binding and dissociation were monitored by quartz crystal microbalance (QCM), confocal fluorescence, native electrophoresis, laser-induced fluorescence, and electrochemical impedance methods.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acrylamides / chemistry*
  • Acrylic Resins
  • Biosensing Techniques / instrumentation*
  • Biosensing Techniques / methods
  • Equipment Design
  • Equipment Failure Analysis
  • Equipment Reuse*
  • Immunoassay / instrumentation*
  • Polymers / chemistry*
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Serum Albumin, Bovine / analysis*
  • Temperature

Substances

  • Acrylamides
  • Acrylic Resins
  • Polymers
  • poly-N-isopropylacrylamide
  • Serum Albumin, Bovine