Chitosan Micro-Membranes with Integrated Gold Nanoparticles as an LSPR-Based Sensing Platform
Diana I. Meira,
Manuela Proença,
Rita Rebelo,
Ana I. Barbosa,
Marco S. Rodrigues,
Joel Borges,
Filipe Vaz,
Rui L. Reis,
Vitor M. Correlo
Affiliations
Diana I. Meira
Physics Center of Minho and Porto Universities (CF-UM-UP), Campus de Azurém, University of Minho, 4800-058 Guimarães, Portugal
Manuela Proença
Physics Center of Minho and Porto Universities (CF-UM-UP), Campus de Azurém, University of Minho, 4800-058 Guimarães, Portugal
Rita Rebelo
3 B’s Research Group, I3Bs—Research Institute on Biomaterials, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Biodegradables and Biomimetics of University of Minho, AvePark—Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Guimarães, Portugal
Ana I. Barbosa
3 B’s Research Group, I3Bs—Research Institute on Biomaterials, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Biodegradables and Biomimetics of University of Minho, AvePark—Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Guimarães, Portugal
Marco S. Rodrigues
Physics Center of Minho and Porto Universities (CF-UM-UP), Campus de Azurém, University of Minho, 4800-058 Guimarães, Portugal
Joel Borges
Physics Center of Minho and Porto Universities (CF-UM-UP), Campus de Azurém, University of Minho, 4800-058 Guimarães, Portugal
Filipe Vaz
Physics Center of Minho and Porto Universities (CF-UM-UP), Campus de Azurém, University of Minho, 4800-058 Guimarães, Portugal
Rui L. Reis
3 B’s Research Group, I3Bs—Research Institute on Biomaterials, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Biodegradables and Biomimetics of University of Minho, AvePark—Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Guimarães, Portugal
Vitor M. Correlo
3 B’s Research Group, I3Bs—Research Institute on Biomaterials, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine, Biodegradables and Biomimetics of University of Minho, AvePark—Parque de Ciência e Tecnologia, Zona Industrial da Gandra, 4805-017 Guimarães, Portugal
Currently, there is an increasing need to develop highly sensitive plasmonic sensors able to provide good biocompatibility, flexibility, and optical stability to detect low levels of analytes in biological media. In this study, gold nanoparticles (Au NPs) were dispersed into chitosan membranes by spin coating. It has been demonstrated that these membranes are particularly stable and can be successfully employed as versatile plasmonic platforms for molecular sensing. The optical response of the chitosan/Au NPs interfaces and their capability to sense the medium’s refractive index (RI) changes, either in a liquid or gas media, were investigated by high-resolution localized surface plasmon resonance (HR-LSPR) spectroscopy, as a proof of concept for biosensing applications. The results revealed that the lowest polymer concentration (chitosan (0.5%)/Au-NPs membrane) presented the most suitable plasmonic response. An LSPR band redshift was observed as the RI of the surrounding media was incremented, resulting in a sensitivity value of 28 ± 1 nm/RIU. Furthermore, the plasmonic membrane showed an outstanding performance when tested in gaseous atmospheres, being capable of distinguishing inert gases with only a 10−5 RI unit difference. The potential of chitosan/Au-NPs membranes was confirmed for application in LSPR-based sensing applications, despite the fact that further materials optimization should be performed to enhance sensitivity.
