Luminescent Self-Assembled Monolayer on Gold Nanoparticles: Tuning of Emission According to the Surface Curvature

• Published in: Chemosensors Vol. 10; no. 5; p. 176
• Main Authors: Candreva, Angela, Di Maio, Giuseppe, Parisi, Francesco, Scarpelli, Francesca, Crispini, Alessandra, Godbert, Nicolas, Ricciardi, Loredana, Nucera, Antonello, Rizzuto, Carmen, Barberi, Riccardo C., Castriota, Marco, La Deda, Massimo
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.05.2022
• Subjects: Aggregates; Correlation; Curvature; Emission analysis; emission spectroscopy; Gold; gold nanorods; gold nanospheres; gold nanotriangles; Monolayers; Nanoparticles; Raman spectroscopy; self-assembled monolayer; Self-assembled monolayers; Self-assembly; Spectrum analysis; the curvature of nanosurface
• ISSN: 2227-9040; 2227-9040
• DOI: 10.3390/chemosensors10050176

Until now, the ability to form a self-assembled monolayer (SAM) on a surface has been investigated according to deposition techniques, which in turn depend on surface-coater interactions. In this paper, we pursued two goals: to form a SAM on a gold nanosurface and to correlate its formation to the nanosurface curvature. To achieve these objectives, gold nanoparticles of different shapes (spheres, rods, and triangles) were functionalized with a luminescent thiolated bipyridine (Bpy-SH), and the SAM formation was studied by investigating the photo-physics of Bpy-SH. We have shown that emission wavelength and excited-state lifetime of Bpy-SH are strongly correlated to the formation of specific aggregates within SAMs, the nature of these aggregates being in close correlation to the shape of the nanoparticles. Micro-Raman spectroscopy investigation was used to test the SERS effect of gold nanoparticles on thiolated bipyridine forming SAMs.