Adsorption of decapeptide neuromedin B (NMB) on copper electrode has been investigated by
in situ
surface-enhanced Raman scattering (SERS) spectroelectrochemistry in the temperature interval from 12
to 72
1
Cat
0.600 and
1.000 V potentials. It was found that intensities of peptide bands decrease at
temperatures above 30
1
C with higher decrease slope at
1.000 V. Frequency of F12 mode (1004 cm
1
)
of non-surface-interactive phenylalanine residue was found to be insensitive to temperature variation at
both studied electrode potentials, while frequency–temperature curves for surface-interactive groups
(Amide-III, methylene) were found to be controlled by the potential. In particular, opposite
frequency–temperature trends were detected for Amide-III (Am-III) mode indicating decrease in
H-bonding interaction strength of amide C
Q
O and N–H groups above 38
1
Cfor
0.600 V, and increase
in H-bonding interaction strength between 12 and 72
1
Cfor
1.000 V. Anomalous Am-III temperature-
dependence of the frequency at
1.000 V was explained by temperature-induced transformation of a
disordered secondary structure to a helix-like conformation. The potential-difference spectrum revealed
interaction of methylene groups with Cu surface at sufficiently negative potential values because of the
appearance of a soft C–H stretching band near 2825 cm
1
and a broad band near 2904 cm
1
assigned
to vibration of a distal C–H bond of the surface-confined methylene group. Consequently, a rapid
decrease in frequency of CH
2
-stretching band with temperature was observed at
1.000 V, while no
essential frequency changes were detected for this mode at
0.600 V. The results show that electrode
potential controls the temperature-dependence of the frequency for vibrations associated with surface-
interactive molecular groups