Table 2. Raman Shift Values from SEHRS and SERS Spectra of Guanine with Hydroxylamine (AgHA) and Citrate (AgCit) Reduced Silver Nanoparticles and Assignment to Vibrations of the Guanine Molecule (Based on Reference (34)).

Raman shift/cm–1a
SEHRS		SERS
AgHA	AgCit	AgHA	AgCit	plane	assignmentsb
1664 m	1666 w	1694 s	1696 s	in	str C6=O, C5–C6, bend N1–H, sciss NH2
1562 vs	1570 s			in	sciss NH2, str C2–N10
		1543 w	1541 w	in	ring str C–N, sciss NH2, bend N1–H
		1523 m	1521 m	in	ring str C–N, bend N9–H
1455 s	1460 s	1457 s	1461 s	in	ring str C–N, bend C8–H, N1–H, N10–H
1385 w	1376 w	1382 s	1388 s	in	ring str C–N, C–C, rock NH2, bend N1/9–H-
		1351 m	1352 m	in	bend N1–H, N10–H12, str C2–N10
1289 m	1260 m	1298 m	1299 m	in	ring str C–N, C–C, bend C8–H, rock NH2
1229 m	1225 m	1211 m	1231 m	in	bend C8–H, str N5–N7, N7–C8
		1148 w	1147 w	in	rock NH2, ring str C–N
1051 vw	1097 m	1055 vw	1057 w	in	str N1–C2, C2–N3
995 m?	1016 br?			in	rock NH2, ring str C–N
	964 w	956 w	957 w	in	5-ring def
865 m	857 m	864 w		in/out	5-ring def, 6-ring def, wag N9–H, N1–H
725 w	726 w			in	6-ring def, bend C6=O
653 w	656 w	658 vs	660 vs	in/out	6-ring breath, 5-ring def, wag NH2
572 s	570 s	575 w	574 w	in	6-ring def
517 vs	517 vs	520 m	519 m	in	6-ring def
459 w?	463 w?			in	bend C2–N10

^avs, very strong; s, strong; m, medium; w, weak; vw, very weak; br, broad.

^bBend, bending; breath, breathing; def, deformation; rock, rocking; sciss, scissoring; str, stretching; wag, wagging; 5-ring, five-membered ring; 6-ring, six-membered ring.