Binding interaction of a fluoranthene–thiol on gold nanoparticles with β-cyclodextrin and DNA

Abstract

In this paper, we report the preparation of a fluoranthene–thiol derivative, the assembly of the compound onto gold nanoparticles, and their binding to β-cyclodextrin and DNA. The synthesised fluoranthene–thiol is characterised using infra-red (IR), nuclear magnetic resonance (NMR), and mass spectrometric techniques. The gold nanoparticles are characterised using transmission electron microscopy and energy dispersive X-ray spectroscopy microanalysis. The size of the nanoparticles is 5 ± 1 nm. The thiol–gold nanoparticles bind to β-cyclodextrin, and DNA and the fluorescence spectra show enhancement of fluorescence on the binding. The thiol–gold nanoparticles form a host–guest complex with β-cyclodextrin and the binding constant of the complex is 1330 mol−1 dm3. This reveals the openness of the thiol on the surface of the gold nanoparticles.