Table 2: SERS spectral peak assignment of 4-ATPa and 4-NTPb.

SERS peak (cm−1) of 4-ATPAssignmentSERS peak (cm−1) of 4-NTPAssignment

390 (CS)332 (CS)
635 (CCC)723 (CH) + (CS) + (CC)
1005 (CC) + (CCC)854 (CH)
1079 (CS)1081 (CS)
1177 (CH)1110 (CH)
1485 (CC) + (CH)1340 (NO2)
1587 (CC)1569 (CC)

The peak assignment of 4-ATP is from [24, 25].
bThe peak assignment of 4-NTP is from [25].