Gold-silver nanoclusters having dipicolinic acid imprinted nanoshell for Bacillus cereus spores recognition

Talanta. 2009 Jun 15;78(4-5):1332-8. doi: 10.1016/j.talanta.2009.02.007. Epub 2009 Feb 13.

Abstract

Molecular imprinted polymers (MIPs) as a recognition element for sensors are increasingly of interest and MIP nanoclusters have started to appear in the literature. In this study, we have proposed a novel thiol ligand-capping method with polymerizable methacryloylamidocysteine (MAC) attached to gold-silver nanoclusters, reminiscent of a self-assembled monolayer and have reconstructed surface shell by synthetic host polymers based on molecular imprinting method for recognition. In this method, methacryloyl iminodiacetic acid-chrome (MAIDA-Cr(III)) has been used as a new metal-chelating monomer via metal coordination-chelation interactions and dipicolinic acid (DPA) which is a main participant of Bacillus spores has been used as a template. Nanoshell sensors with templates give a cavity that is selective for DPA. The DPA can simultaneously chelate to Cr(III) metal ion and fit into the shape-selective cavity. Thus, the interaction between Cr(III) ion and free coordination spheres has an effect on the binding ability of the gold-silver nanoclusters nanosensor. The binding affinity of the DPA imprinted nanoclusters has been investigated by using the Langmuir and Scatchard methods and determined affinity constants (K(affinity)) were found as 18 x 10(6) mol L(-1) and 9 x 10(6) mol L(-1), respectively.

MeSH terms

  • Bacillus cereus / cytology*
  • Bacteriological Techniques
  • Chelating Agents
  • Gold
  • Metal Nanoparticles / chemistry*
  • Molecular Imprinting / methods*
  • Picolinic Acids / chemistry*
  • Polymers / chemistry
  • Silver
  • Spores, Bacterial / isolation & purification*

Substances

  • Chelating Agents
  • Picolinic Acids
  • Polymers
  • Silver
  • Gold
  • dipicolinic acid