| AVS 65th International Symposium & Exhibition | |
| Processing and Characterization of Air-Liquid, Solid-Liquid and Air-Solid Interfaces Focus Topic | Wednesday Sessions |
| Session PC+AS+BI+EM+PB+SS-WeM |
| Session: | Novel Approaches and Challenges of Interfaces |
| Presenter: | Rachel Komorek, Pacific Northwest National Laboratory |
| Authors: | R. Komorek, Pacific Northwest National Laboratory X.F. Yu, Pacific Northwest National Laboratory Z.H. Zhu, Pacific Northwest National Laboratory X-Y. Yu, Pacific Northwest National Laboratory |
| Correspondent: | Click to Email |
Riboflavin is of vital significance in living processes as a precursor of the two important coenzymes flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD).[1] The isoalloxazine ring in riboflavin plays an important role in energy supplementation and cellular respiration, since it has the capability to accept electrons in some redox reactions.[2] Understanding riboflavin reduction could potentially bring insight into the electron transfer process between cell surfaces and conductive materials. Thus, the electrochemical reduction process of riboflavin has drawn increasing attention. In this study, the riboflavin reduction mechanism in an aqueous solution has been investigated using time-of-flight secondary ion mass spectrometry (ToF-SIMS) with the electrochemical cell.[3, 4] Positive and negative ion mode mass spectra were used to depict the molecular information of species dissolved in the electrolyte. The distribution of key reduction intermediates were mapped at the electrode-electrolyte interface using dynamic depth profiling. To examine product formation as a function of applied potentials, measurements were made by holding the potential at 0, -0.3, 0.3, and 0.6 V respectively, once interesting electrochemistry was determined using the cyclic voltammogram. Furthermore, gold and graphite electrodes were both used in our experiment to investigate if the electrode surface plays a role in in the electrochemical reaction mechanism. Preliminary spectral principal component analysis (PCA) results have shown key chemical distinctions in the electrolyte at 0, -0.3, 0.3, and 0.6 V. Selected peak spectral PCA is required to gain a better understanding of this observation, which will allow for a more comprehensive chemical profile of the electron transfer process in riboflavin redox reactions.
Key words: in situ liquid SIMS, SALVI, riboflavin reduction, electrochemistry, electron transfer
References
1. Y Wang, G Zhu, E Wang, Electrochemical behavior of FAD at a gold electrode studied by electrochemical quartz crystal microbalance. Anal. Chem. Acta. (1997), 338, 97-101.
2. W Chen, J-J Chen, R Lu, C Qian, W-W Li, H-Q Yu, Redox reaction characteristics of riboflavin: A fluorescence spectroelectrochemical analysis and density functional theory calculation. Bioelectrochemistry (2014), 98, 103-8.
3. B Liu, et al., In situ chemical probing of the electrode–electrolyte interface by ToF-SIMS. Lab Chip (2014), 14, 855-9.
4. J Yu et al., Capturing the transient species at the electrode-electrolyte interface by in situ dynamic molecular imaging. Chem. Comm. (2016), 73, 10929-11206.