Nanoparticles featuring amino acid-functionalized side chains as DNA receptors

A family of nanoparticles has been fabricated fea-turing cationic amino acid-based side chains. Thiscontrolled surface modification provides a tool toinvestigate the effect of various non-covalentinteractions at the nanoparticle–DNA interface.The binding affinities of these nanoparticlestowards DNA were determined using fluorescence,exhibiting more than threefold modulation in bind-ing a 37-mer DNA strand. The secondary structureof the DNA strand was distorted upon nanoparti-cle binding, with the extent of distortion depend-ent on the structure of amino acid side chain.Key words: amino acid, DNA, nanoparticleReceived 1 June 2007, revised 1 June 2007 and accepted for publica-tion 2 June 2007