This is the first report of the use of hand-held 1064 nm Raman spectrometer combined with red shifted SERS nanotags to provide an unprecedented performance in the short-wave infrared (SWIR) region. A library consisting of 17 chalcogenopyrylium nanotags produce extraordinary SERS responses with femtomolar detection limits being obtained using the portable instrument. This is well beyond previous SERS detection limits at this far red shifted wavelength and opens up new options for SERS sensors in the SWIR region of the electromagnetic spectrum (between 950-1700 nm).
Table 1 - Values of the absorption maximum (λmax) and calculated LOD values from the SERS experiment with associated standard deviation error for 17 chalcogenopyrylium dyes plus BPE and AZPY adsorbed onto HGNs using a hand-held 1064 nm Raman spectrometer.
Figure 1 – Comparison of SERS spectra for chalcogenopyrylium dye 16 with the commercial Raman reporter BPE.
Figure 2 - SERS particle dilution studies for chalcogenopyrylium dye 16 plus commercial Raman reporter BPE with HGNs and KCl over the concentration range 2 nM to 0.1 pM.
The dataset is embargoed for six months while a patent application is developed. See ‘readme file’ for details on file content.