Nanostructured DNA Microarrays for Dual SERS and Electrochemical Read-out

We present a strategy to fabricate nanostructured microarrays ready to perform a dual read-out, namely electrochemical (EC) as well as surface-enhanced Raman spectroscopy (SERS) based detection of DNA hydridization. A polystyrene nanobeads monolayer assembly, obtained by means of a Langmuir Blodgett type technique, followed by electrochemical Au deposition, was employed to construct homogeneous nanostructures in the form of inverse-opal nanovoids on a 32-electrode Au microarray chip. Characterization of the obtained nanostructured electrodes of the array by means of cyclic voltammetry demonstrated high reproducibility of the surface modification process. The performance of the obtained array platform was investigated by modifying the microarray electrodes with three different oligonucleotide capture probes using a previously developed potential-assisted surface modification protocol. Two ferrocene-labeled target DNA sequences and one target RNA sequence with a Texas red label were detected electrochemically and via SERS, respectively.