Table 4.

SERS enhancements for the different test Ag substrates, in this study: As illustrated by the absolute intensities (AI, counts ± standard error of mean, n = 4) and enhancement factors (EF × 10⁵) for the ~1076 cm⁻¹ and the ~1595 cm⁻¹ SERS peaks for 1 mM MBT as a function of chemical etching, with and without heat treatments using 514 nm laser wavelength.

	1076 cm−1				1595 cm−1
	Non-Heated		Heated		Non-Heated		Heated
	AI Counts	EF × 105	AI Counts	EF × 105	AI Counts	EF × 105	AI Counts	EF × 105
Native Ag Substrate	1728 ± 629	3.3	1209 ± 901	2.3	1883 ± 779	5.3	1087 ± 957	3.0
30 s NH4OH	2104 ± 266	4.0	933 ± 414	1.8	1630 ± 126	4.6	815 ± 283	2.3
10 s HNO3	3506 ± 446	6.6	2352 ± 330	4.5	3656 ± 584	10.2	1876 ± 357	5.2
2 m HNO3	1035 ± 336	2.0	1884 ± 337	3.6	4672 ± 622	13.1	1563 ± 362	4.4
30 s NH4OH + 10 s HNO3	5825 ± 849	11.0	2093 ± 549	4.0	6027 ± 989	16.9	3166 ± 964	8.9
30 s NH4OH + 2 m HNO3	1994 ± 495	3.8	434 ± 109	0.8	2257 ± 540	6.3	476 ± 92	1.3