The optimization of oligonucleotide conjugation onto gold nanoparticles for biodetection

In this paper we present the optimization procedure for the application of gold nanoparticles as a system for the detection of oligonucleotides. The gold nanoparticles have been conjugated to a pair of 5´-alkanethiol-modified 20 base oligonucleotides, designed to align in a tail-to-head manner. Upon hybridization with the complementary target, the plasmon region of the spectra registers a large red-shift, thus forming a reliable colorimetric system for the detection of oligonucleotides.