The development of accurate, reliable, inexpensive and fully recyclable analytical platforms is of utmost relevance to several fields from medical diagnosis to environmental screening. Surface-enhanced Raman spectroscopy (SERS) is a compelling detection method with high specificity and sensitivity. In this work, a microwave-assisted synthesis method was used for fast and uniform in situ growth of gold nanoparticles (AuNPs) onto nanocellulose (NC) membranes, through a seed-mediated process. The as-prepared membranes were fully optimized and its application as SERS platforms was demonstrated. A direct comparison with other cellulose-based substrates showed the superior characteristics of NC such as high mechanical strength, high surface area and lower porous content. An Enhancement Factor (EF) up to ~106 was obtained using rhodamine 6G (R6G) 10−6 M as probe molecule and a remarkable shelf life of at least 7 months was achieved, with no special storage requirements. Preliminary results on the label-free detection of spike protein from SARS-CoV-2 virus are shown, through direct measurements on the optimized SERS membrane. We believe that this work evidences the effectiveness of in situ seed-mediated microwave-assisted synthesis as a fabrication method, the high stability of AuNPs and the superior characteristics of NC substrates to be used as SERS platforms.
Bibliographical noteKAUST Repository Item: Exported on 2022-06-15
Acknowledgements: This work is funded by National Funds through FCT I.P., under the scope of the project UIDB/50025/2020-2023. The authors acknowledge the ERC AdG project DIGISMART ref. 787410 and EC project SYNERGY H2020-WIDESPREAD-2020-5, CSA, proposal no. 952169. Also, the authors thank funding co-financed by the Operational Programme for Competitiveness and Internationalisation (COMPETE 2020) and Lisbon Regional Operational Programme (Lisboa 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF) under the projects ECO2COVID ref. 68174 and TecniCOV ref. 69745. A. C. Marques acknowledges funding from FCT I.P., through the PhD Grant SFRH/BD/115173/2016. The authors acknowledge Professor Pedro Costa from KAUST for the TEM imaging.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.
ASJC Scopus subject areas
- Surfaces, Coatings and Films