The ability to tune the localised surface plasmon resonance (LSPR) behaviour of metal nanostructures has great importance for many optical sensor applications such as metal (plasmon) enhanced fluorescence spectroscopy and surface-enhanced Raman scattering (SERS). In this paper, we used Aerosol Direct Writing (ADW) to selectively deposit fine gold nanoparticles (AuNPs) patterns. A low-temperature thermal post-treatment (below 200 °C) provides enough energy to merge and transform AuNPs into larger features significantly different from non-thermally treated samples. The optical behaviour of non-treated and thermally treated AuNP films was investigated by photoluminescence (PL) spectroscopy. The PL measurements showed a red-shift, compared to bulk gold, using 488 nm and 514 nm laser excitation, and a blue-shift using 633 nm laser excitation. The thermal post-treatment leads to a further blue-shift compared to non-treated samples in the presence of both 514 and 633 nm laser. Finally, the AuNPs patterns were employed as a SERS-active substrate to detect low-concentrated (10−8 M) rhodamine B. This method's ability to selectively deposit 3D gold nanostructures and tune their optical behaviour through a low-temperature thermal treatment allows optimisation of the optical response and enhancement of the Raman signal for specific bio-analytes.

DOI: 10.1039/D1RA02266K

Click HERE to read the full paper.

To speak with one of our Sales & Applications Engineers please call 01582 764334 or click here to email.

Lambda Photometrics is the leading UK Distributor of Characterisation, Measurement and Analysis solutions with particular expertise in Instrumentation, Laser & Light based products, Optics, Electro-optic Testing, Spectroscopy, Machine Vision, Optical Metrology, Fibre Optics, Microscopy and Anti-vibration tables & custom solutions