Superhydrophobic surfaces as smart platforms for the analysis of diluted biological solutions

The aim of this paper is to expound on the rational design, fabrication and development of superhydrophobic surfaces (SHSs) for the manipulation and analysis of diluted biological solutions. SHSs typically feature a periodic array or pattern of micropillars; here, those pillars were modified to incorporate on the head, at the smallest scales, silver nanoparticles aggregates. These metal nanoclusters guarantee superior optical properties and especially SERS (surface enhanced Raman scattering) effects, whereby a molecule, adsorbed on the surface, would reveal an increased spectroscopy signal. On account of their two scale-hybrid nature, these systems are capable of multiple functions which are (i) to concentrate a solution, (ii) to vehicle the analytes of interest to the active areas of the substrate and, therefore, (iii) to measure the analytes with exceptional sensitivity and very low detection limits. Forasmuch, combining different technologies, these devices would augment the performance of conventional SERS substrates and would offer the possibility of revealing a single molecule. In this work, similar SHSs were used to detect Rhodamine molecules in the fairly low atto molar range. The major application of this novel family of devices would be the early detection of tumors or other important pathologies, with incredible advances in medicine.