Self-organization of silver and copper in porous matrices: Surface Structure and SERS Studies

• Applicants: Dr. Dana Cialla-May; Dr. Vladimir Sivakov
• Subject Area: Synthesis and Properties of Functional Materials
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 465289819

The targeted scientific breakthrough of the proposed project is a study of a controlled and self-organized process of localized nanostructures in porous silica matrix on silicon surface where dielectric pores are selectively filled by plasmonic active metals (silver and copper). A formation and surface structure of dimensionally divided plasmonic nanostructures for biosensor application using surface enhanced Raman spectroscopy (SERS) will be deeply studied in the frame of proposed project. It is very important and challenging to understand the formation mechanism of plasmonic metal nanostructures arrays with even more complex, but adjustable structures, using simpler routes under mild conditions and to investigate in details the kinetics’ of self-organization processes of silver (Ag) and copper (Cu) nanostructures in limited volumes (pores) and atomic/electronic surface structure, which is the main challenge of this project. The influence of processing parameters such as porous matrix formation (comparison between swift heavy ion track and lithography techniques), Ag and Cu self-organized growth mechanism in closed-volume has not yet been fundamentally investigated. To realize this ambitious project the scientific expertise and long experience in the project related fields (material science, semiconductor technology, Raman spectroscopy and plasmonics) of two groups: Dr. Sivakov and Dr. Cialla-May are required. The characterization of nanostructures will be carried out by surface analytic methods (SEM, EDX, EBSD, TEM, etc.) which are combined with theoretical modeling of growth processes and Raman scattering properties. For a careful and detailed analysis of the formed structures surface and interfaces atomic and electronic structure as well as local atomic surrounding and generally physico-chemical states the following methods will be applied: X-ray Absorption Near Edge Structure (synchrotron source) and X-ray Photoelectron Spectroscopy using open access large scale facilities at HZB BESSY II in Germany. Ex-situ and in-situ modifications of localized self-organized metal nanostructures will allow to expand the understanding of the material properties and stability for further application in SERS-based sensoric. Within the proposed project it is aimed to apply Ag and Cu substrates as SERS-active substrates for investigations in complex matrices such as artificial blood plasma, sputum, urine and protein-containing matrices such as cultural supernatants to illustrate the potential of the developed SERS substrates for detection schemes in medical sciences.

• DFG Programme: Research Grants