Nanoparticle-Imprinted Polymers for Size-Selective Recognition of Nanoparticles

Authors


  • This work was supported financially by the German Israeli Foundation (research grant no. 1074-49.10/2009) and The Harvey M. Krueger Family Center for Nanoscience and Nanotechnology of the Hebrew University. S. K.-O. acknowledges the support of the Eshkol and CAMBR Scholarships. We thank A. E. Wright (Thermo Fischer Scientific) for expert technical support in performing the XPS measurements.

Abstract

Citrate-stabilized gold nanoparticles 15 nm and 33 nm in diameter were transferred concomitantly with a monolayer of positively charged polyaniline by Langmuir–Blodgett transfer at pH 5 onto a conducting indium-doped tin oxide (ITO) support. Films consisting of one to three layers of polyaniline with thicknesses of 1–3 nm were prepared and characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy. After electro-oxidation of the Au nanoparticles in 0.1 M KCl, cavities were left behind in the film that could be analyzed by SEM. These cavities were able to recapture analyte nanoparticles from a solution of pH 10 and showed size-exclusion properties. The amount of nanoparticles taken up by the cavities was conveniently analyzed by measuring the charge associated with the electro-oxidation of these particles in 0.1 M KCl after the film had been rinsed with water. The size-exclusion properties improved with the number of Langmuir–Blodgett layers transferred.

Ancillary