| Autor: |
Akbali B; Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ, UK. s.maher@liverpool.ac.uk.; Department of Engineering and System Science, National Tsing Hua University, Hsinchu 30013, Taiwan., Boisdon C; Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ, UK. s.maher@liverpool.ac.uk., Smith BL; Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ, UK. s.maher@liverpool.ac.uk., Chaisrikhwun B; Program in Petrochemistry and Polymer Science, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand., Wongravee K; Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand., Vilaivan T; Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand., Lima C; Centre for Metabolomics Research, Department of Biochemistry, Cell and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool, L69 7ZB, UK., Huang CH; Department of Biomedical Engineering, National Central University, Zhongli 10608, Taiwan., Chen TY; Department of Engineering and System Science, National Tsing Hua University, Hsinchu 30013, Taiwan., Goodacre R; Centre for Metabolomics Research, Department of Biochemistry, Cell and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool, L69 7ZB, UK., Maher S; Department of Electrical Engineering and Electronics, University of Liverpool, Brownlow Hill, Liverpool, L69 3GJ, UK. s.maher@liverpool.ac.uk. |
| Abstrakt: |
Surface-enhanced Raman scattering (SERS) is a powerful technique for detecting trace amounts of analytes. However, the performance of SERS substrates depends on many variables including the enhancement factor, morphology, consistency, and interaction with target analytes. In this study, we investigated, for the first time, the use of electrospray deposition (ESD) combined with a novel ambient focusing DC ion funnel to deposit a high density of gold nanoparticles (AuNPs) to generate large-area, uniform substrates for highly sensitive SERS analysis. We found that the combination of ambient ion focusing with ESD facilitated high-density and intact deposition of non-spherical NPs. This also allowed us to take advantage of a polydisperse colloidal solution of AuNPs (consisting of nanospheres and nanorods), as confirmed by finite-difference time domain (FDTD) simulations. Our SERS substrate exhibited excellent capture capacity for model analyte molecules, namely 4-aminothiophenol (4-ATP) and Rhodamine 6G (R6G), with detection limits in the region of 10 -11 M and a relative standard deviation of <6% over a large area (∼500 × 500 μm 2 ). Additionally, we assessed the quantitative performance of our SERS substrate using the R6G probe molecule. The results demonstrated excellent linearity ( R 2 > 0.99) over a wide concentration range (10 -4 M to 10 -10 M) with a detection limit of 80 pM. |
