Molecular recognition by gold, silver and copper nanoparticles

Abstract

The intrinsic physical properties of the noble metal nanoparticles, which are highly sensitive to the nature of their local molecular environment, make such systems ideal for the detection of molecular recognition events. The current review describes the state of the art concerning molecular recognition of Noble metal nanoparticles. In the first part the preparation of such nanoparticles is discussed along with methods of capping and stabilization. A brief discussion of the three common methods of functionalization: Electrostatic adsorption; Chemisorption; Affinity-based coordination is given. In the second section a discussion of the optical and electrical properties of nanoparticles is given to aid the reader in understanding the use of such properties in molecular recognition. In the main section the various types of capping agents for molecular recognition; nucleic acid coatings, protein coatings and molecules from the family of supramolecular chemistry are described along with their numerous applications. Emphasis for the nucleic acids is on complementary oligonucleotide and aptamer recognition. For the proteins the recognition properties of antibodies form the core of the section. With respect to the supramolecular systems the cyclodextrins, calix[n]arenes, dendrimers, crown ethers and the cucurbitales are treated in depth. Finally a short section deals with the possible toxicity of the nanoparticles, a concern in public health.

Keywords: Hybrid nanoparticles; Gold; Silver; Copper; Metal; Molecular recognition; DNA; Protein; Supramolecular assembly; Toxicity

Core tip: The article is an in-depth review of the state of the art of molecular recognition processes involving hybrid nanoparticles and bio-molecular substrates. We describe the methods of preparation and physical characterization. The capping by proteins, DNA, peptides and supramolecular assemblies, including cyclodextrins, calix[n]arenes, cucurbitales, dendrimers and crown ethers is then discussed. There is a large analysis of the interactions of these systems with various substrates, such as complimentary oligo-nucleotides, antibodies, active pharmaceutical ingredients and polluants. Finally we discuss the problem of possible toxicity.