Figure 1.
A schematic diagram of the silver-intensified cationic gold nanoparticle on the surface of the cell.
The 15 nm cationic gold particle is shown interacting with the cell glycocalyx molecules.
Figure 2.
Scanning electron micrographs of the apical surface of endothelial cells.
Corneal endothelium (A, B). Endothelium with 1/10 silver-intensified cationic gold (C). Endothelium with 1/10 silver-intensified cationic gold at a high magnification (D). (A) Scale bar = 5 µm; (B) Scale bar = 5 µm; (C) Scale bar = 10 µm; and (D) Scale bar = 5 µm. Insert ×5.
Figure 3.
Histogram showing the range of diameters of silver-intensified cationic gold nanoparticles on the corneal endothelial cell surface.
Figure 4.
Mean spectra from the five different classes of samples; the spectra have been baseline corrected.
The different treatments consist of: 1/10 silver-intensified gold (1/10 Au with Ag); 1/100 silver-intensified gold (1/100 Au with Ag); 1/10 gold without silver-intensification (1/10 Au only); silver-intensification solution without gold (Ag solution only) and PBS solution (PBS treatment only).
Figure 5.
Three-D cluster plot of four different sample classes with 95% confidence ellipsoids.
The classes consist of: 1/10 silver-intensified gold (1/10 Au with Ag); 1/100 silver-intensified gold (1/100 Au with Ag); 1/10 gold without silver-intensification (1/10 Au only) and PBS solution (PBS treatment only).
Figure 6.
Mean spectra (light blue) of the 1/10 silver-intensified gold samples.
Showing the spectral peaks which demonstrate the highest levels of SERS-enhancement. The pack with the highest level of enhancement is at 611 cm−1.
Figure 7.
The PCA cluster vectors with the PBS-treated control samples set as the origin.
The green plot consists of 1/10 gold only samples deviates only slightly from the origin, but both plots from the 1/100 silver-intensified gold (red) and the 1/10 silver-intensified gold (light blue) samples are surprisingly similar over the 1000–600 cm−1 spectral regions. Both plots show maximum deflection from the origin around the 611 cm−1 spectral region.
Figure 8.
Light micrograph of endothelium.
Endothelial cell treated with 1/10 silver-intensified gold nanoparticles (A). Scale bar = 10 µm. SERS-enhanced spectral map of the same region taken at a wavenumber of 611 cm−1 (B).
Table 1.
Tentative peak assignations for the most enhanced peaks of the spectra.