Electrode modified with toluidine blue-doped silica nanoparticles, and its use for enhanced amperometric sensing of hemoglobin

  • Meichuan Liu
  • , Guoyue Shi
  • , Li Zhang
  • , Guohua Zhao*
  • , Litong Jin
  • *Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

21 Scopus citations

Abstract

Three-dimensionally structured, silica based, organic-inorganic hybrid nanoparticles (NPs) were prepared by a simple and feasible water-in-oil (W/O) microemulsion method and a promising platform for bioelectrochemical analysis was obtained. The commonly used phenathiazine organic compound, toluidine blue (TB) was readily captured in the three-dimensional cage of the inorganic SiO2 network, which was considered to serve as a protective "shell" toward the embedded TB. A TEM image indicated the size of the thus prepared TB-doped SiO2 (TB@SiO2) NPs was 21 ± 3 nm. UV-visible and IR spectroscopy confirmed successful formation of the organic-inorganic composite and possible interaction between TB and SiO 2, which favored enhanced stability of the hybrid. A sensitive amperometric sensor for hemoglobin (Hb) biomolecules based on TB@SiO2 NPs conjugated with a biopolymer chitosan (CHIT) membrane was then developed. The surface of the silica NPs was highly biocompatible and the TB captured inside maintained its high electron-transfer efficiency. Dye leakage of TB from the TB@SiO2 hybrid was proved to be minimal, owing to the inorganic SiO2 network and the force of interaction between TB and SiO 2. The amperometric sensor had a detection limit of 2.5 × 10-9 mol L-1 (S/N = 3) with a linear range from 5.0 × 10-9 to 3.0 × 10-6 mol L-1 for Hb. When it was applied to determine the concentration of a clinical blood sample, satisfactory results were obtained which were in good agreement with those obtained by the standard method.

Original languageEnglish
Pages (from-to)1951-1959
Number of pages9
JournalAnalytical and Bioanalytical Chemistry
Volume391
Issue number5
DOIs
StatePublished - Jul 2008

Keywords

  • Amperometric sensor
  • Hemoglobin
  • Toluidine blue-doped silica nanoparticles
  • Water-in-oil microemulsion

Fingerprint

Dive into the research topics of 'Electrode modified with toluidine blue-doped silica nanoparticles, and its use for enhanced amperometric sensing of hemoglobin'. Together they form a unique fingerprint.

Cite this