Table 1.

The average enhancement factors calculated for the nanocubes of 38 nm in edge length and nanospheres of 35 nm in diameter used in this study ^a.

molecule	orientation	bandb	mode	nanocube	std. dev.	nanosphere	std. dev.
1,4-BDT		1561	8a  Ag	5.8 × 105	2.7 × 102	5.7 × 102	1.7 × 102
		1183	9a  Ag	6.6 × 105	1.1 × 103	8.1 × 102	9.8 × 101
4-MBT		1593	8a  Ag	5.5 × 105	9.4 × 102	2.6 × 102	9.4 × 101
		1072	7a  Ag	5.9 × 105	2.7 × 102	3.8 × 102	6.8 × 101
1-PT		706	(C-S)t	9.2 × 104	8.3 × 101	1.5 × 102	1.1 × 101
		890	(CH3)rock	3.9 × 104	1.9 × 102	9.9 × 101	1.8 × 101

^aThe average EFs were calculated for the 8a vibrational mode (1561 cm⁻¹) and the 9a vibrational mode (1183 cm⁻¹) of 1,4-benzenedithiol (1,4-BDT); the 8a vibrational mode (1593 cm⁻¹) and the 7a vibrational mode (1072 cm⁻¹) of 4-methyl benzenethiol (4-MBT); and the S-C stretching mode (706 cm⁻¹) and the CH₃ rocking mode (890 cm⁻¹) of 1-pentanethiol (1-PT). All experiments used a 514 nm excitation laser and were performed in water.

^bWavenumber in cm⁻¹. The molecular footprint, or area occupied the molecules on the metal surface, were 0.54 nm² for 1,4-BDT, 0.19 nm² for 4-MBT, and 0.21 nm² for 1-PT and were taken from references [24], [50], and [51] respectively. Note that in the molecular cartoon white is hydrogen, black is carbon, yellow is sulfur and the plane is a metal surface.