Photoattachment of thiolated DNA probes on SU-8 spin-coated Blu-ray disk surfaces for biosensing

A methodology to modify Blu-ray disk (BD) surfaces by spin-coating an SU-8 epoxy photoresist is evaluated, to create a hybrid material with new functionalities. The optical performance of the new film surface disk is analyzed. The light-mediated activation of epoxy-to-thiol chemistry is applied to the site-specific and covalent binding of thiol-ended oligonucleotide probes to the SU-8 disk surface. For the optimized hybridization conditions, a limit of detection of 1 pM is reached employing enzymatic development. PCR products, from a Salmonella typhimurium serotype, are detected at an amplicon concentration of 20 pM. The reading of the assays is performed using a commercial BD-player.