Plasma Fabrication and SERS Functionality of Gold Crowned Silicon Submicrometer Pillars

Abstract

Sequential plasma processes combined with specific lithographic methods allow for the fabrication of advanced material structures. In the present work, we used self-assembled colloidal monolayers as lithographic structures for the conformation of ordered Si submicrometer pillars by reactive ion etching. We explored different discharge conditions to optimize the Si pillar geometry. Selected structures were further decorated with gold by conventional sputtering, prior to colloidal monolayer lift-off. The resulting structures consist of a gold crown, that is, a cylindrical coating on the edge of the Si pillar and a cavity on top. We analysed the Au structures in terms of electronic properties by using X-ray absorption spectroscopy (XAS) prior to and after post-processing with thermal annealing at 300 °C and/or interaction with a gold etchant solution (KI). The angular dependent analysis of the plasmonic properties was studied with Fourier transformed UV-vis measurements. Certain conditions were selected to perform a surface enhanced Raman spectroscopy (SERS) evaluation of these platforms with two model dyes, prior to confirming the potential interest for a well-resolved analysis of filtered blood plasma.

Stable and scalable SERS tags conjugated with neutravidin for the detection of fibroblast activation protein (FAP) in primary fibroblasts

“…To maximize the signal obtained by the SERS tag, and thus to decrease the time requested for the analysis of a sample, SERS images were acquired using a 632,8 nm laser light source. In fact, while in principle a 785 nm laser could have provided a higher Enhancement factor, in our experience, the use of a red laser resulted advantageously from the practical point of view [10,36,37]. FAP expression on the cells was confirmed by flow cytometry after two passages in culture (figure S2).…”

Plasma meets metamaterials: Three ways to advance space micropropulsion systems

“…Etching [71,72] (i.e. material sputtering in the presence of a chemically active reagent to weaken the atomic bonds on the surface of the material) and deposition [73,74] are the most applied technological operations where plasmas are used [75].…”

Manipulation and Applications of Hotspots in Nanostructured Surfaces and Thin Films

“…The synthesis of nanostructured surfaces and thin films using physical vapor deposition, such as pulsed laser deposition, magnetron sputtering, thermal evaporation, e-beam evaporation, among others, plays a key role in the development of a variety of applications in nanoplasmonics, nanoscale photovoltaic devices, nanogenerators, flexible or nanobiological sensors, and so on [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. For devices based on nanostructured surfaces and thin films, diverse high-fidelity geometry is important for the performance of the devices in practical applications.…”