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Scanning Electrochemical Microscopy of Living Cells
Published in Allen J. Bard, Michael V. Mirkin, Scanning Electrochemical Microscopy, 2022
Changyue Du, Thilini Suduwella, Isabelle Beaulieu, Steen B. Schougaard, Janine Mauzeroll
Koley et al.148 have used SECM to study the oxidative stress induced by menadione (2-methyl-1,4-napthaquinone) in live HeLa cells. The hydrophobic menadione is toxic to the cells as it induces the oxidative stress by forming ROS. In the presence of glutathione-S-transferase, menadione converts into thiodione which then can be recognized by the ATP-driven MRP1 pump and pumped out across the cell membrane. In this study, the extracellular thiodione concentration was detected using SECM in real time in the presence and absence of the MRP1 inhibitor MK571 and MRP1 blocker QCRL-4. The decrease of thiodione concentration in the presence of MRP1 inhibitor and blocker confirmed the importance of MRP1 pumps in the detoxification process.148
Menadione sodium bisulfite neutralizes chromium phytotoxic effects in okra by regulating cytosolutes, lipid peroxidation, antioxidant system and metal uptake
Published in International Journal of Phytoremediation, 2021
Muhammad Arslan Ashraf, Rizwan Rasheed, Sadia Zafar, Muhammad Iqbal, Zulfiqar Ahmad Saqib
Different approaches, conventional and genetic engineering, are being used for plant protection from phytotoxic impacts of metals (Adrees et al. 2015; Keller et al. 2015; Rasheed et al. 2018). Such approaches help improve plant defense mechanisms, including enhanced biosynthesis of organic solute as proline. Besides shotgun approaches, the exogenous application of inorganic and organic compounds has been customized for plant protection against such stresses (Adrees et al. 2015; Rasheed et al. 2018). MSB, which is an acronym of menadione sodium bisulfite, is a derivative of vitamin K that protects plants from biotic and abiotic stresses (Jiménez-Arias et al. 2015; Carrillo-Perdomo et al. 2016; Jiménez-Arias et al. 2019). MSB generates small oxidative damage that develops intricate ROS signaling networks and thereby enhanced the production of defense-related proteins (Rasheed et al. 2018; Jiménez-Arias et al. 2019). To the best of our knowledge, there exists no information on the role of MSB in okra under Cr toxicity. The major objective of the present investigation is to ascertain the impact of MSB application in okra exposed to Cr stress and evaluate important components that mediate plant responses to Cr stress. The study was planned to investigate how far MSB application improved plant growth through alterations in secondary metabolites accumulation, oxidative defense system and degree of oxidative damage. The findings of the present investigation would highlight the potential of MSB as plant growth regulator to improve Cr tolerance in okra and other important horticultural crops.
Progress on electrochemical sensors for the determination of heavy metal ions from contaminated water
Published in Journal of the Chinese Advanced Materials Society, 2018
Xiangzi Dai, Shuping Wu, Songjun Li
Electrochemical whole cell biosensor is a biosensor that uses electrochemical electrodes as signal converter and cell as biological sensitive element to detect signals through electric potential, impedance or current.[79] The whole cell is used as a biological recognition element, based on the stress response produced by specific stimulation between whole cell and metal ions, and amplify the signals. Gao et al. investigated the feasibility and sensitivity of a double-mediator based whole cell electrochemical biosensor to detect heavy metal ions from wastewater.[80] The lipophilic mediator menadione was utilized to mediate the intracellular metabolic activities whereas hydrophilic potassium ferricyanide was employed as extracellular electron acceptor to transport the electron from the menadiol to anode. A natural polymer chitosan film with boron-doped nanocrystalline diamond (BND) particles was electrodeposited onto a GCE to immobilize Saccharomyces cerevisiae cells and the mediators. The as-prepared electrochemical biosensor was characterized by the detecting Cu(II), Cd(II), Ni(II) and Pb(II). Figure 6(a) illustrates the schematic procedure of fabrication of the BND-chitosan hydrogel polymer biosensor, and Figure 6(b) describes the surface morphology and the cyclic voltammetry curves of BND-chitosan polymer film biosensor. As displayed in Figure 6(c), the half maximal inhibitory concentration (IC50) values of the biosensor for Cu(II), Cd(II), Ni(II) and Pb(II) are 10.12, 13.88, 17.06 and 34.56 mg/L, respectively. The results revealed that the whole cell electrochemical biosensor based on the double-mediator had excellent performance and could be applied in the field of wastewater toxicity online detection.