Electric-field-directed self-assembly of active enzyme-nanoparticle structures

J Biomed Biotechnol. 2012:2012:178487. doi: 10.1155/2012/178487. Epub 2012 Feb 1.

Abstract

A method is presented for the electric-field-directed self-assembly of higher-order structures composed of alternating layers of biotin nanoparticles and streptavidin-/avidin-conjugated enzymes carried out on a microelectrode array device. Enzymes included in the study were glucose oxidase (GOx), horseradish peroxidase (HRP), and alkaline phosphatase (AP); all of which could be used to form a light-emitting microscale glucose sensor. Directed assembly included fabricating multilayer structures with 200 nm or 40 nm GOx-avidin-biotin nanoparticles, with AP-streptavidin-biotin nanoparticles, and with HRP-streptavidin-biotin nanoparticles. Multilayered structures were also fabricated with alternate layering of HRP-streptavidin-biotin nanoparticles and GOx-avidin-biotin nanoparticles. Results showed that enzymatic activity was retained after the assembly process, indicating that substrates could still diffuse into the structures and that the electric-field-based fabrication process itself did not cause any significant loss of enzyme activity. These methods provide a solution to overcome the cumbersome passive layer-by-layer assembly methods to efficiently fabricate higher-order active biological and chemical hybrid structures that can be useful for creating novel biosensors and drug delivery nanostructures, as well as for diagnostic applications.

MeSH terms

  • Avidin / chemistry
  • Avidin / metabolism
  • Biosensing Techniques / instrumentation
  • Biosensing Techniques / methods*
  • Biotin / chemistry
  • Biotin / metabolism
  • Electromagnetic Fields
  • Glucose / analysis
  • Glucose Oxidase / chemistry*
  • Glucose Oxidase / metabolism
  • Lab-On-A-Chip Devices
  • Luminol / chemistry
  • Luminol / metabolism
  • Nanoparticles / chemistry*
  • Nanoparticles / ultrastructure
  • Streptavidin / chemistry
  • Streptavidin / metabolism

Substances

  • Avidin
  • Luminol
  • Biotin
  • Streptavidin
  • Glucose Oxidase
  • Glucose