Nanoporous Gold: A High Sensitivity and Specificity Biosensing Substrate

Abstract Unambiguous identification of analyte biomolecules with high quantitative sensitivity and specificity continues to be a biosensing challenge. In this work, we demonstrate a micromachined quartz resonator array with nanoporous gold electrode as a highly sensitive substrate for biosensing applications. Furthermore, using surface enhanced Raman spectroscopy (SERS) the nanoporous gold substrate can be used to obtain label free detection of biomolecules with very high selectivity. Enhanced gravimetric sensitivity to 24-mer oligonucleotide binding reaction was achieved due to the increased electrode surface area. This dual mode sensing of biomaterials allows for unique identification of the attached biomolecules on the sensor surface via SERS whereas the quartz resonator provides a very accurate quantitative measure of the analyte. This paper presents the first results on the application of nanoporous gold (np- Au) electroded micromachined quartz resonators for detection of DNA hybridization reaction using simultaneous gravimetric and SERS measurements.