DNA thermal stability with and without covalently linked gold nanocrystals.

Melting temperatures for unmodified, single-labeled and double-labeled DNA duplexes. The increase in melting temperature upon addition of the A nanocrystal is the same whether or not the B nanocrystal is present, indicating a zero coupling energy between the two nanocrystals. The samples were approximately 10 µM concentration in 1 M NaCl, 0.05 mM EDTA, and 10 mM sodium phosphate, pH 7.0. The reported error is the difference between three independent measurements.