Nanoplasmonic sensors designed by plasmas

Today, there are several well-established research directions where plasmonic detection is employed extensively; namely, food and water quality monitoring, viruses, pathogenic bacteria and hazardous toxin investigations for theranostic applications, and other purposes. A combination of vibrational spectroscopy and surface nanoengineering has gained a reputation as a powerful tool for rapid and accurate determination of submolecular quantities of nanoanalytes. Signal enhancement achieved by employing various metallic nanoparticles and nanostructures can be amplified significantly due to the electromagnetic field confinement effect. Localized surface plasmon waves, which are responsible for the phenomenon, promote light absorption at nanovolume, generating ‘hot spots’ with an incredibly intense and confined electromagnetic field close to the nanosculptured metallic surface. However, the formation of the hot spot network is heavily dependent on morphology, size, and spatial arrangement of plasmonic nanomaterials. Under optimal excitation conditions, the interaction between the optically induced electromagnetic field in the hot spot region and a probing analyte attached to the nanosculptured metallic substrate enlarges photon scattering cross-section, increasing signal intensity by 10⁶–10¹⁰. As a result, fast single-molecule vibrational fingerprint recording is possible. Here plasma fabrication of such nanoplasmonic surfaces was used due to its versatility compared to other nanofabrication techniques, its reliability, single-step and fast processing. This presentation highlights our recent research in the design of nanoplasmonic surfaces with plasmas, highlighted by supreme performances from the detection of toxic molecules down to DNA sampling.