| AVS 64th International Symposium & Exhibition | |
| Applied Surface Science Division | Wednesday Sessions |
| Session AS+BI+MI+NS+SA+SS-WeM |
| Session: | Beyond Traditional Surface Analysis: Pushing the Limits |
| Presenter: | Jun-Gang Wang, East China University of Science and Technology; Pacific Northwest National Laboratory (PNNL) |
| Authors: | J.G. Wang, East China University of Science and Technology; Pacific Northwest National Laboratory (PNNL) Y. Zhang, PNNL X.Y. Yu, PNNL Z.H. Zhu, PNNL |
| Correspondent: | Click to Email |
In situ monitoring of electrochemical reactions is traditionally performed by cyclic voltammetry[1], plasmonic spectroelectrochemistry[2, 3], and surface probing techniques such as scanning electrochemical microscopy and scanning ion conductive microscope.[4] However, it has been extremely difficult to obtain direct molecular evidence of the electrochemical reaction intermediates using these traditional techniques. Thus, the debate of rection machnisms has long been an issue. Recently, mass spectrometric techniques have been coupled with electrochemistry to provide the molecular information of intermediates of redox reactions.[5] The advantage of mass spctetrometric techniques is that capture of molecular ions can provide direct molecular information of key chemical species, such as rection intermediates. A novel approach, based on coupling of time-of-flight secondary ion mass spectrometry (ToF-SIMS) and electrochemistry has been developed in Pacific Northwest National Laboratory and it has been used for in situ analysis of reaction intermediates in electro-oxidation of ascorbic acid at the electrode–electrolyte interface.[6] Herein, the electrochemical oxidation of acetaminophen was chosen as a model system, which simulated the function of oxidase enzymes cytochrome P-450 to catalyze the oxidation of acetaminophen.[7] This reaction was real-time monitored using in situ ToF-SIMS. The highly reactive N-acetyl-p-benzoquinone-imine (NAPQI) was captured. The NAPQI subsequently conjuated with glutathione and cysteine was molecularly confirmed. We demonstrated the proof of principle for the use of ToF-SIMS for real-time monitoring of electrochemical reaction with high chemical specificity. Our results demonstrate that the coupling of ToF-SIMS and electrochemistry has great potential to molecularly elucidate reaction machnisms in the oxidative metabolism, pharmaceutical intoxification, and cell toxicology.
References
[1] J.-G. Wang, X. Cao, X. Wang, S. Yang, R. Wang, Electrochim. Acta 2014, 138, 174.
[2] J.-G. Wang, J. S. Fossey, M. Li, D.-W. Li, W. Ma, Y.-L. Ying, R.-C. Qian, C. Cao, Y.-T. Long, J. Electroanal. Chem. 2016, 781, 257.
[3] J.-G. Wang, C. Jing, Y.-T. Long, in Frontiers of Plasmon Enhanced Spectroscopy Volume 2, Vol. 1246, American Chemical Society, 2016, pp. 57.
[4] J. T. Cox, B. Zhang, Annu. Rev. Anal. Chem. 2012, 5, 253.
[5] T. A. Brown, H. Chen, R. N. Zare, J. Am. Chem. Soc. 2015, 137, 7274.
[6] Z. Wang, Y. Zhang, B. Liu, K. Wu, S. Thevuthasan, D. R. Baer, Z. Zhu, X.-Y. Yu, F. Wang, Anal. Chem. 2017, 89, 960.
[7] D. C. Dahlin, G. T. Miwa, A. Y. Lu, S. D. Nelson, Proc. Natl. Acad. Sci. 1984, 81, 1327.