Abstract
[Display omitted]
► Super-hydrophobic surfaces (SHSs) were designed and micro-fabricated. ► These incorporate nanoporous silicon films and silver nanoparticles. ► On account of super-hydrophobicity, diluted solutions can be concentrated. ► On account of nanoporous silicon, ‘small’ molecules can be retained. ► On account of silver nanoparticles, SERS measurements can be performed.
Super-hydrophobic surfaces were designed and micro-fabricated. These comprise micro-pillars combined to form a regular hexagonal motif; the pillars were conveniently modified to incorporate nanoporous silicon films. Silver nanoparticles were dispersed into the pores to guarantee superior SERS (surface enhanced Raman scattering) capabilities. On account of its multiscale nature, the substrate exhibits an increased hydrophobicity and a reduced friction coefficient. This device is multiplexed in the sense that features different functions or abilities, including (i) the concentration of diluted solutions, (ii) the separation of ‘small’ molecules basing on an exclusion principle and (iii) the SERS measurement of these molecules with extreme accuracy. In consideration of the properties above, the device may be employed for investigating systematically the blood serum, and extracting from this the low molecular weight content, that discloses precious information about the ongoing status of tumors or other diseases. Here, analytes were separated and detected in the femto molar (10−15M) range.