Selective on site separation and detection of molecules in diluted solutions with super-hydrophobic clusters of plasmonic nanoparticles

Abstract
Super-hydrophobic surfaces are bio-inspired interfaces with a superficial texture that, in its most common evolution, is formed by a periodic lattice of silicon micro-pillars. Similar surfaces reveal superior properties compared to conventional flat surfaces, including very low friction coefficients. In this work, we modified meso-porous silicon micro-pillars to incorporate networks of metal nano-particles into the porous matrix. In doing so, we obtained a multifunctional-hierarchical system in which (i) at a larger micrometric scale, the super-hydrophobic pillars bring the molecules dissolved in an ultralow-concentration droplet to the active sites of the device, (ii) at an intermediate meso-scale, the meso-porous silicon film adsorbs the low molecular weight content of the solution and, (iii) at a smaller nanometric scale, the aggregates of silver nano-particles would measure the target molecules with unprecedented sensitivity. In the results, we demonstrated how this scheme can be utilized to isolate and detect small molecules in a diluted solution in very low abundance ranges. The presented platform, coupled to Raman or other spectroscopy techniques, is a realistic candidate for the protein expression profiling of biological fluids. © 2014 the Partner Organisations.

Citation
Gentile, F., Coluccio, M. L., Zaccaria, R. P., Francardi, M., Cojoc, G., Perozziello, G., … Di Fabrizio, E. (2014). Selective on site separation and detection of molecules in diluted solutions with super-hydrophobic clusters of plasmonic nanoparticles. Nanoscale, 6(14), 8208–8225. doi:10.1039/c4nr00796d

Acknowledgements
This work has been partially funded by the EU Commission, the European Social Fund and the Calabria Region (POR Calabria FSE 2007-2013), from the Italian Minister of Health under the project "Cancer biomarker detection using micro-structured/super-hydrophobic surfaces and advanced spectroscopy techniques" (Project no. GR-2010-2320665), and the project "High throughput analysis of cancer cells for therapy evaluation by microfluidic platforms integrating plasmonic nanodevices" (Project no. GR-2010-2311677), and from the Cariplo Foundation under the project "New Frontiers in Plasmonic Nano-sensing" (Grant no. 2011-0338).

Publisher
Royal Society of Chemistry (RSC)

Journal
Nanoscale

DOI
10.1039/c4nr00796d

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