Polymer-coated magnetic nanoparticles (MNPs) have been prepared and used as an immobilization matrix for the fabrication of solid-state tris(2,2′-bipyridyl)ruthenium(II) (Ru(bpy)32+) electrogenerated chemiluminescence (ECL) sensor. The pre-synthesized maghemite (γ-Fe2O3) MNPs were coated with poly(3-thiopheneacetic acid) based on an oxidative polymerization method using KMnO4. The poly(3-thiopheneacetic acid)-coated MNPs have formed the clusters with average diameter of 200-500 nm. The multilayer films of poly(3-thiopheneacetic acid)-coated MNPs were uniformly formed on the surface of a Pt electrode by an external magnet. The Ru(bpy)32+ was rapidly incorporated into the multilayer films within 5 min through the electrostatic interaction between the Ru(bpy)32+ and the negatively charged carboxylates of 3-thiopheneacetic acid at pH 7.0. Due to the fast mass transport in the multilayer films of the functionalized MNPs, the present Ru(bpy)32+ ECL sensor based on the functionalized MNPs showed improved ECL sensitivity for tripropylamine (TPA) compared to the Nafion-based ECL sensor. The present ECL sensor exhibited a quite low limit of detection for TPA (49 nM). The sensor-to-sensor reproducibility was very good (R.S.D. = 5%).
Bibliographical noteFunding Information:
This work was supported by Korea Research Foundation Grant (KRF-2007-C-00484) and Yonsei-CBMH. K.J.K., Y.K.L and J.H.H acknowledge the support of the BK 21 program of the Ministry of Education and Science.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry