Binary monolayers of single-stranded oligonucleotides and blocking agent for hybridisation

The hybridisation of thiol-modified single-stranded DNA (SH-ssDNA) embedded in lipoate or hydrophilic polymer monolayers on gold have been studied through the technique of surface plasmon resonance (SPR). SH-ssDNA and the blocking agents were co-adsorbed on gold from the same solution or the surface was post-treated with the blocking agents. The assembling process is allowed to take place for only 10 min. Binding of non-complementary and complementary DNA is dependent both on the blocking agent and on the assembling method used. The lowest non-complementary binding and the highest complementary binding of DNA was obtained with a layer assembled from a binary solution of SH-ssDNA and the lipoate blocking agent.