Structural effects of internucleotide linkage modification at mismatch site in DNA/RNA duplex: Raman study

SVD‐based method for intensity normalization, background correction and solvent subtraction in Raman spectroscopy exploiting the properties of water stretching vibrations

“…[10] Two types of internal standards are chosen: either Raman bands of chemical species constituting an integral part of the sample, e.g. solvent peaks or particular Raman bands of the analyte itself, [2,11] or bands of a foreign compound added to the sample ad hoc, e.g. ClO 4 − , NO 3 − , SO 4 2− , SeO 4 2− or PO 4 2− ions.…”

“…ClO 4 − , NO 3 − , SO 4 2− , SeO 4 2− or PO 4 2− ions. [11,12] In both cases, an ideal internal standard should provide intense, clearly resolvable Raman features not coinciding with other Raman bands and remaining unaffected by the physicochemical parameter varied over the entire range of interest. In addition, the internal standard should not be photochemically active or significantly absorb the excitation or Raman scattered light.…”

“…[9] Water molecules provide a broad, weak band centered at 1640 cm −1 and a broad, strong band centered at 3400 cm −1 . Despite its weakness, it is a common practice to use as a standard the 1640 cm −1 band belonging to deformation vibration, [4,9,11] as its position, intensity and line shape are less sensitive to ionic strength and temperature (or anything else that affects hydrogen bonding) than those of the stronger 3400 cm −1 band. However, this approach provides less satisfactory results for analytes having their own Raman signal between the 1550 and 1700 cm −1 .…”