Modulating Infrared Absorption Enhancement of a Meso Substituted BODIPY Dye on Langmuir–Blodgett Thin Films of Graphenic Substrates

• DOI: 10.1007/s11468-025-02829-4
• Publication Date: 2025-03-12T07:38:46Z
• Authors: Emmanuel de la O-...; Violeta Álvarez-V...; A. A. Ortíz-Herná...; J. J. Ortega-Sigala; H. Tototzintle-Hu...; María del Pilar C...; E. L. Esparza-Ibarra; José M. Saniger
• Keywords: BODIPY

Abstract Graphene-based materials, such as graphene oxide (GO) and reduced graphene oxide (rGO), are 2D materials known for their unique physicochemical properties, including the ability to enhance the vibrational spectroscopic signals of some molecules adsorbed on their surface. These properties offer an opportunity to develop micro- or nanostructured systems based on graphenic substrates for detecting and identifying various analytes with high sensitivity and reliability through molecular spectroscopic techniques. In this study, we tested the ability of a few layers GO and rGO substrates to enhance the infrared absorption band intensities of a highly fluorescent meso substituted BODIPY (BP) derivative compound when deposited on it. BP compounds family have important applications ranging from solar energy conversion to photodynamic cancer therapy and then the development of an improved methodology for its identification and sensitive detection by FTIR is of interest in the characterization of those systems. Our aim was to investigate the behavior of GO and rGO as active substrates for the enhancement of the vibrational signals of BP through the graphene-enhanced infrared absorption (GEIRA) effect. For this purpose, GO, rGO, and BP layers were prepared using the Langmuir–Blodgett (LB) technique, allowing us to mitigate the effects of material agglomeration and optimize the enhancement of the IR signal of the BODIPY dye. Our findings suggest that by controlling the interlayer arrangements and the chemical groups attached to graphenic substrates, the performance of their surface plasmons can be modulated, optimizing their interaction with adsorbed molecules and thus enhancing the IR absorption signal.