Effect of DNA-induced corrosion on passivated porous silicon biosensors.

Zhao Y, Lawrie JL, Beavers KR, Laibinis PE, Weiss SM
ACS Appl Mater Interfaces. 2014 6 (16): 13510-9

PMID: 25089918 · DOI:10.1021/am502582s

This work examines the influence of charge density and surface passivation on the DNA-induced corrosion of porous silicon (PSi) waveguides in order to improve PSi biosensor sensitivity, reliability, and reproducibility when exposed to negatively charged DNA molecules. Increasing the concentration of either DNA probes or targets enhances the corrosion process and masks binding events. While passivation of the PSi surface by oxidation and silanization is shown to diminish the corrosion rate and lead to a saturation in the changes by corrosion after about 2 h, complete mitigation can be achieved by replacing the DNA probe molecules with charge-neutral PNA probe molecules. A model to explain the DNA-induced corrosion behavior, consistent with experimental characterization of the PSi through Fourier transform infrared spectroscopy and prism coupling optical measurements, is also introduced.

MeSH Terms (11)

Biosensing Techniques Corrosion DNA DNA Probes Magnesium Optical Phenomena Peptide Nucleic Acids Porosity Silanes Silicon Spectroscopy, Fourier Transform Infrared

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