Abstract
In this work, we study the electrocatalytic detection of H2O2 at electrodes correspondingly modified by four hourglass-shaped polyoxometallates (POMs) with Cu, Co, Mn and Cs as their individual central metal atoms, and four representative Wells-Dawson POMs with the same metal atoms. In this way, we have related their analytical performance to the open structures of hourglass-shaped POMs and the cage-like structures of Wells-Dawson POMs. Among them, we found the three-dimensional hourglass phosphomolybdate (POM 1) with plentiful exposed Cu active sites exhibits a dynamic range of 0.1–10 μM, a sensitivity of 11.6μAμM−1cm−2, and a limit of detection as low as 44 nM for H2O2. It also offers high selectivity, fast response time (2s), a reproducibility of ∼1.69% and retains ∼97.9% of the initial current after 15 days, verifying its good stability. Accordingly, the POM 1-modified electrode was applied to monitoring H2O2 converted from superoxide anion radical (O2•−) generated by mitochondria isolated and purified from human liver cancer cells (HepG2) without pharmaceutical stimulation. Meanwhile, by exploiting four specific inhibitors (rotenone, 2-thenoyltrifluoroacetone, antimycin A and paclitaxel) known to bind with targeted sites in the corresponding complex within mitochondria to produce a high H2O2 concentration, our results indicated that O2•− was mainly produced by mitochondrial complex I (ubiquinone oxidoreductase) via electron leakage in the mitochondrial electron transport chain of liver cancer. The electrochemical detection strategy in our work has provided a direct insight into the electron leakage of mitochondrial complexes caused by targeted oxidative stress diseases.
Original language | English |
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Article number | 146302 |
Pages (from-to) | 1-12 |
Number of pages | 12 |
Journal | Chemical Engineering Journal |
Volume | 475 |
Early online date | 27 Sept 2023 |
DOIs | |
Publication status | Published - 1 Nov 2023 |
Bibliographical note
Copyright the Author(s) 2023. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.Keywords
- Electrocatalyst
- Electrochemical sensor
- HO reduction
- Mitochondria
- Polyoxometallates