Incorporating β-cyclodextrin with ZnO nanorods: a potentiometric strategy for selectivity and detection of dopamine

Sensors (Basel). 2014 Jan 17;14(1):1654-64. doi: 10.3390/s140101654.

Abstract

We describe a chemical sensor based on a simple synthesis of zinc oxide nanorods (ZNRs) for the detection of dopamine molecules by a potentiometric approach. The polar nature of dopamine leads to a change of surface charges on the ZNR surface via metal ligand bond formation which results in a measurable electrical signal. ZNRs were grown on a gold-coated glass substrate by a low temperature aqueous chemical growth (ACG) method. Polymeric membranes incorporating β-cyclodextrin (β-CD) and potassium tetrakis (4-chlorophenyl) borate was immobilized on the ZNR surface. The fabricated electrodes were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The grown ZNRs were well aligned and exhibited good crystal quality. The present sensor system displays a stable potential response for the detection of dopamine in 10(-2) mol·L(-1) acetic acid/sodium acetate buffer solution at pH 5.45 within a wide concentration range of 1 × 10(-6) M(-1) × 10(-1) M, with sensitivity of 49 mV/decade. The electrode shows a good response time (less than 10 s) and excellent repeatability. This finding can contribute to routine analysis in laboratories studying the neuropharmacology of catecholamines. Moreover, the metal-ligand bonds can be further exploited to detect DA receptors, and for bio-imaging applications.

MeSH terms

  • Dopamine / chemistry*
  • Microscopy, Electron, Scanning
  • Nanotubes / chemistry*
  • Nanotubes / ultrastructure
  • Potentiometry / methods*
  • X-Ray Diffraction
  • Zinc Oxide / chemistry*
  • beta-Cyclodextrins / chemistry*

Substances

  • beta-Cyclodextrins
  • betadex
  • Zinc Oxide
  • Dopamine