In situ Fourier transform infrared reflection absortion spectroscopy study of adenine adsorption on gold electrodes in basic media

Advances in surface-enhanced vibrational spectroscopy at electrochemical interfaces

“…For example, Xu and co-workers studied the electroreduction of CO 2 on Cu electrodes and reported that CO and H are able to co-adsorb at low overpotentials, but H can partially displace CO due to stronger Cu-H binding [144]. EC-SEIRAS has also found recent application in the study of photochemical reactions [147,148], electrochemical processes in ionic liquids [149,150], and a wide range of adsorption phenomena at metal electrodes [151][152][153][154][155][156][157]. Rodes et al monitored the adsorption of glycine on Au thin films using EC-SEIRAS and confirmed that the preferential binding mode is in a bidentate configuration (Figure 7(b)) and that co-adsorption of perchlorate anions from the electrolyte takes place [156].…”

The Use of Voltammetry for Sorption Studies of Arsenic (III) Ions by Magnetic Beads Functionalized with Nucleobase Hydrazide Derivatives

“…Hence, pH 4.1 was chosen for further experiments. The purine nucleobases have 2 pk a s: guanine with pK a1 =3.2–3.3 and pk a2 =9.2–9.6 [27] and adenine with pk a1 =4.2 and pK a2 =9.8 [28]. Thus, at pH 4.1, guanine exists predominantly in the neutral keto tautomeric form, while adenine at a pH close to pK a1 related to the protonation of the pyrimidine nitrogen exists in both the positive and neutral forms.…”

The Controversial Orientation of Adenine on Gold and Silver

“…Although these careful investigations cannot simply be dismissed, they tend to focus on interpretation of just several bands, whereas SERS/DFT studies proposing N3/N9 adsorption have simulated entire spectra with remarkable accuracy. In addition, while no paper can discuss or even cite everything done in the past (hence the purpose of this Minireview), curiously, the recent IR‐based studies on gold in this series have made no references whatsoever to previous SERS studies reporting the N3/N9 adsorption model of adenine on gold and silver, yet SERS studies supporting N7/N10 adsorption on silver have been cited therein . It will therefore be important to properly reconcile these seemingly contradictory results.…”

“…Using SEIRAS under attenuated total reflection conditions (ATR‐SEIRAS), adsorption of adenine onto a Au(111) electrode in acidic media was investigated, but the authors were unable to propose a definite adsorption model . Further work in basic media using ATR‐SEIRAS and subtractively normalized interfacial Fourier transform infrared spectroscopy (SNIFTIRS) supported adsorption by the N1/N10 or N7/N10 atoms . In the same series of work, an ATR‐SEIRAS study investigated the interactions of co‐adsorbed adenine and thymine on gold thin‐film electrodes in acidic media.…”