Developing nanoparticle arrays for improved sensing using electron-beam lithography
Francesco MURA (Sapienza Università di Roma)
In this work, performed in collaboration with Dr. Fabio Domenici (Dpt. Of Chemical Science and Technologies, Università di Roma Tor Vergata Rome, Italy), Dr. Claudia Fasolato, Dr. Francesco Brasili, Prof. Paolo Postorino and Prof. Federico Bordi (Dpt. Of Physics, Sapienza Università di Roma, Italy), it will be discussed the realization of accurate and reproducible arrays through the electron beam lithography. In fact, the electron beam is able to create arrays of regularly-disposed area on the PMMA (polymethylmetacrylate) thin film, previously deposited by spin-coating on the Si wafer, with a precision on the nanoscale. These “nanowells” are subsequently treated with different protocols of functionalization, in order to induce the covalent self-assembled aggregation of gold NPs and so to obtain dense, highly packed NP clusters of micrometric size and spacing regularity.
The morphological characterization of the patterns has been realized by Atomic Force Microscopy measurements, while the high and reproducible optical signals displayed on the corresponding array periodicities are enlightened by preliminary microRaman analysis. The demonstrated approach may be useful particularly in the aim of realizing benchmark NCAs, featured as stable and reproducible gold NP clusters in the mesoscopic scale, leading to the challenging production of improved opto- and conductive-microfluidic multiplex-sensing.
