{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,8]],"date-time":"2026-10-08T13:56:57Z","timestamp":1791467817511,"version":"4.3.4"},"reference-count":45,"publisher":"American Chemical Society (ACS)","issue":"40","license":[{"start":{"date-parts":[[2026,9,29]],"date-time":"2026-09-29T00:00:00Z","timestamp":1790640000000},"content-version":"stm-asf","delay-in-days":0,"URL":"https:\/\/doi.org\/10.15223\/policy-029"},{"start":{"date-parts":[[2026,9,29]],"date-time":"2026-09-29T00:00:00Z","timestamp":1790640000000},"content-version":"stm-asf","delay-in-days":0,"URL":"https:\/\/doi.org\/10.15223\/policy-037"},{"start":{"date-parts":[[2026,9,29]],"date-time":"2026-09-29T00:00:00Z","timestamp":1790640000000},"content-version":"stm-asf","delay-in-days":0,"URL":"https:\/\/doi.org\/10.15223\/policy-045"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["22072074"],"award-info":[{"award-number":["22072074"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,10,8]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>An oil-in-water microemulsion is an excellent candidate medium for the electrochemical regeneration of the coenzyme NADH and its subsequent coupled conversion application due to its good electrical conductivity and solubilization capacity for hydrophobic substrates. In this work, the reduced methyl viologen (MV+\u2022)-mediated electrochemical reduction of coenzyme NAD+ was studied in a Triton X-100 (TX-100)-stabilized methyl tert-butyl ether (MTBE)-in-water microemulsion. The effects of the surfactant concentration and the oil content on the electrochemical behavior of the MV2+\/MV+\u2022 couple and the activity of diaphorase (DH) were systematically investigated. The results show that in the microemulsion, the couple exhibits excellent reversibility. Compared with the aqueous buffer system, the couple in the microemulsion system has a more positive formal potential and a lower redox peak current, depending on the levels of both the surfactant and the oil. The positive shift of the formal potential is attributed to the stabilizing effect of the surfactant aggregates on the relatively hydrophobic MV+\u2022 species, and the decrease of the redox currents is ascribed to the decrease of the electroactive area of the electrode due to the adsorption of the surfactant and the oil as well as the decrease of the diffusion coefficients of MV species associated with or solubilized in the surfactant aggregates. The activity of DH in the microemulsion system also depends on the TX-100 concentration and the MTBE content. Increases in both [TX-100] and [MTBE] result in a decrease in DH activity. This phenomenon could be explained based on the [TX-100]\/[MTBE]-dependent changes in the local acidity and the local concentration of the substrate DCPIP in the microemulsions. Based on cyclic voltammetry, the MV+\u2022-mediated electroreduction of NAD+ in the TX-100-stabilized MTBE\/H2O (0.1 M PB, pH = 7.0) microemulsion was studied. For the microemulsion system containing 0.5 mM MV2+, 5 mM NAD+, and 26.6 \u03bcM DH, when a scan rate of 2 mV s\u20131 was applied, a typical steady-state S-shaped CV curve was obtained. UV\u2013vis spectroscopy confirms that the NADH generated by the mediated reaction is bioactive. By coupling the MV+\u2022-mediated NADH electrochemical regeneration reaction with the horse liver alcohol dehydrogenase (HLADH)-catalyzed reduction of the hydrophobic substrate 4-phenyl-2-butanone, the enantiomerically pure (S)-4-phenyl-2-butanol can be selectively obtained. After 12 h, the yield of the product in the microemulsion is approximately 10 times that in the DMSO-buffer mixed homogeneous system. This difference in yield is caused by the differences in enzyme activity and stability, as well as in the substrate local concentration and reactivity in the two systems. The present study indicates that the TX-100-stabilized MTBE-in-water microemulsion is a suitable medium for the electrochemical regeneration of NADH and the electroenzymatic conversion of water-insoluble substrates catalyzed by NADH-dependent oxidoreductases.<\/jats:p>","DOI":"10.1021\/acs.jpcb.6c04531","type":"journal-article","created":{"date-parts":[[2026,9,29]],"date-time":"2026-09-29T19:03:05Z","timestamp":1790708585000},"page":"10438-10447","source":"Crossref","is-referenced-by-count":0,"title":["Study on the Methyl\nViologen-Mediated Electrochemical\nReduction of Coenzyme NAD+ in the Triton X-100-Stabilized\nMethyl\n                    <i>tert<\/i>\n                    -Butyl Ether-in-H2O\nMicroemulsion"],"prefix":"10.1021","volume":"130","author":[{"given":"Xiaonan","family":"Li","sequence":"first","affiliation":[{"name":"Shandong University , , ,","place":["Jinan, China, 250100"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7531-6283","authenticated-orcid":true,"given":"Xirong","family":"Huang","sequence":"additional","affiliation":[{"name":"Shandong University , , ,","place":["Jinan, China, 250100"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"316","published-online":{"date-parts":[[2026,9,29]]},"reference":[{"key":"2026100809091656300_cit1","doi-asserted-by":"publisher","DOI":"10.1016\/j.ijbiomac.2024.132238","article-title":"Classification and\nFunctional Origins of Stereocomplementary Alcohol Dehydrogenases for\nAsymmetric Synthesis of Chiral Secondary Alcohols: A Review","volume":"270","author":"Zhang","year":"2024","journal-title":"Int. J. Biol. Macromol."},{"issue":"13","key":"2026100809091656300_cit2","doi-asserted-by":"publisher","DOI":"10.1002\/anie.202314740","article-title":"Redox out of the Box:\nCatalytic Versatility across NAD(P)H-Dependent Oxidoreductases","volume":"63","author":"Roth","year":"2024","journal-title":"Angew. Chem., Int. Ed."},{"issue":"7","key":"2026100809091656300_cit3","doi-asserted-by":"publisher","first-page":"1611","DOI":"10.1002\/tcr.202100062","article-title":"Application\nof Ketoreductase in Asymmetric Synthesis of Pharmaceuticals and Bioactive\nMolecules: An Update (2018\u20132020)","volume":"21","author":"Li","year":"2021","journal-title":"Chem.\nRec."},{"issue":"7","key":"2026100809091656300_cit4","doi-asserted-by":"publisher","first-page":"1773","DOI":"10.1039\/c3gc37129h","article-title":"Methods for the Regeneration of Nicotinamide Coenzymes","volume":"15","author":"Wu","year":"2013","journal-title":"Green Chem."},{"issue":"22","key":"2026100809091656300_cit5","doi-asserted-by":"publisher","DOI":"10.1002\/cssc.202200888","article-title":"Redox Biocatalysis: Quantitative\nComparisons of Nicotinamide Cofactor Regeneration Methods","volume":"15","author":"Sharma","year":"2022","journal-title":"ChemSusChem"},{"issue":"5","key":"2026100809091656300_cit6","doi-asserted-by":"publisher","first-page":"621","DOI":"10.1016\/j.chempr.2017.04.009","article-title":"Cofactor NAD(P)H Regeneration Inspired by Heterogeneous Pathways","volume":"2","author":"Wang","year":"2017","journal-title":"Chem"},{"issue":"50","key":"2026100809091656300_cit7","doi-asserted-by":"publisher","first-page":"34298","DOI":"10.1021\/jacs.4c14580","article-title":"Reversible\nElectrocatalytic NAD+\/NADH Interconversion Mediated by\na Pyrazine-Amidate Iridium Complex","volume":"146","author":"Rodriguez","year":"2024","journal-title":"J. Am. Chem.\nSoc."},{"issue":"3","key":"2026100809091656300_cit8","doi-asserted-by":"publisher","DOI":"10.1002\/anie.202111804","article-title":"Bulk Electrocatalytic\nNADH Cofactor Regeneration with Bipolar Electrochemistry","volume":"61","author":"Zhang","year":"2022","journal-title":"Angew. Chem., Int. Ed."},{"key":"2026100809091656300_cit9","doi-asserted-by":"publisher","first-page":"14","DOI":"10.1016\/j.copbio.2021.06.013","article-title":"Advances in Electrochemical Cofactor\nRegeneration: Enzymatic and Non-Enzymatic Approaches","volume":"73","author":"Lee","year":"2022","journal-title":"Curr. Opin. Biotechnol."},{"issue":"38","key":"2026100809091656300_cit10","doi-asserted-by":"publisher","first-page":"11600","DOI":"10.1021\/jp307374z","article-title":"Catalytic\nElectrochemistry of Xanthine\nDehydrogenase","volume":"116","author":"Kalimuthu","year":"2012","journal-title":"J. Phys. Chem. 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Chem."},{"key":"2026100809091656300_cit17","doi-asserted-by":"publisher","DOI":"10.1016\/j.bioelechem.2024.108850","article-title":"Efficient\nBioelectrocatalytic NADH Regeneration with a Novel Amino-Functionalized\nViologen Redox Polymer","volume":"162","author":"Jayakumar","year":"2025","journal-title":"Bioelectrochemistry"},{"issue":"12","key":"2026100809091656300_cit18","doi-asserted-by":"publisher","first-page":"4963","DOI":"10.1021\/jacs.9b00147","article-title":"Upgraded\nBioelectrocatalytic N2 Fixation: From N2 to\nChiral Amine Intermediates","volume":"141","author":"Chen","year":"2019","journal-title":"J. Am. Chem. Soc."},{"issue":"1","key":"2026100809091656300_cit19","doi-asserted-by":"publisher","first-page":"19","DOI":"10.1007\/s12010-008-8442-6","article-title":"Cloning, Expression,\nand Characterization of a Novel (S)-Specific Alcohol Dehydrogenase\nfrom Lactobacillus Kefir","volume":"160","author":"Chen","year":"2010","journal-title":"Appl. Biochem. 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Electroanal. Chem. Interfacial Electrochem."},{"issue":"22","key":"2026100809091656300_cit29","doi-asserted-by":"publisher","first-page":"4876","DOI":"10.1021\/j100268a044","article-title":"Micellar Effects on the Reductive Electrochemistry\nof Methylviologen","volume":"89","author":"Kaifer","year":"1985","journal-title":"J. Phys. Chem. A"},{"issue":"4","key":"2026100809091656300_cit30","doi-asserted-by":"publisher","first-page":"1017","DOI":"10.1111\/j.1471-4159.1988.tb10567.x","article-title":"Demonstration and Biochemical Characterisation\nof Rat Brain NADPH-Dependent Diaphorase","volume":"50","author":"Kuonen","year":"1988","journal-title":"J.\nNeurochem."},{"issue":"11","key":"2026100809091656300_cit31","doi-asserted-by":"publisher","first-page":"1519","DOI":"10.1177\/42.11.7930535","article-title":"Roles of Triton\nX-100 in NADPH-Diaphorase Histochemistry","volume":"42","author":"Fang","year":"1994","journal-title":"J.\nHistochem. Cytochem."},{"key":"2026100809091656300_cit32","doi-asserted-by":"publisher","DOI":"10.1016\/j.ijbiomac.2024.134056","article-title":"Water-Mediated\nActive Conformational Transitions of Lipase on Organic Solvent Interfaces","volume":"277","author":"Zhang","year":"2024","journal-title":"Int. J. Biol. Macromol."},{"issue":"4","key":"2026100809091656300_cit33","doi-asserted-by":"publisher","first-page":"398","DOI":"10.1016\/j.jbiotec.2012.03.011","article-title":"Enzyme Catalysis\nin Organic Solvents:\nInfluence of Water Content, Solvent Composition and Temperature on\nCandida Rugosa Lipase Catalyzed Transesterification","volume":"162","author":"Herbst","year":"2012","journal-title":"J. Biotechnol."},{"issue":"3","key":"2026100809091656300_cit34","doi-asserted-by":"publisher","first-page":"1669","DOI":"10.1021\/acs.joc.1c01136","article-title":"Effect of\nOrganic Solvents on the Structure and Activity of a Minimal Lipase","volume":"87","author":"Ingenbosch","year":"2022","journal-title":"J. Org. Chem."},{"issue":"1","key":"2026100809091656300_cit35","doi-asserted-by":"publisher","first-page":"475","DOI":"10.1021\/acs.jpcb.4c05738","article-title":"Active Site Studies\nto Explain Kinetics of Lipases in Organic Solvents Using Molecular\nDynamics Simulations","volume":"129","author":"Tj\u00f8rnelund","year":"2025","journal-title":"J. Phys. Chem. 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Mater."},{"issue":"5","key":"2026100809091656300_cit38","doi-asserted-by":"publisher","first-page":"769","DOI":"10.1021\/la00077a034","article-title":"Electrochemistry of Methylviologen\nin the Presence\nof Sodium Decyl Sulfate","volume":"3","author":"Quintela","year":"1987","journal-title":"Langmuir"},{"issue":"1","key":"2026100809091656300_cit39","doi-asserted-by":"publisher","first-page":"49","DOI":"10.1039\/cs9811000049","article-title":"Electrochemistry\nof the Viologens","volume":"10","author":"Bird","year":"1981","journal-title":"Chem. Soc. Rev."},{"issue":"9","key":"2026100809091656300_cit40","doi-asserted-by":"publisher","DOI":"10.1149\/1945-7111\/ac21f4","article-title":"An Asymmetric\nViologen-Based Negolyte\nwith a Low Redox Potential for Neutral Aqueous Redox Flow Batteries","volume":"168","author":"Bahari","year":"2021","journal-title":"J. Electrochem. Soc."},{"issue":"1","key":"2026100809091656300_cit41","doi-asserted-by":"publisher","first-page":"194","DOI":"10.1016\/0304-4165(64)90180-1","article-title":"The\nMolar Extinction Coefficient of 2,6-Dichlorophenol Indophenol","volume":"86","author":"Armstrong","year":"1964","journal-title":"Biochim. Biophys. Acta"},{"issue":"19","key":"2026100809091656300_cit42","doi-asserted-by":"publisher","first-page":"5911","DOI":"10.1016\/S0021-9258(17)33039-9","article-title":"The NADH Dehydrogenase\nof the Respiratory\nChain of Escherichia Coli. I. Properties\nof the Membrane-Bound Enzyme, Its Solubilization, and Purification\nto near Homogeneity","volume":"251","author":"Dancey","year":"1976","journal-title":"J. Biol. Chem."},{"key":"2026100809091656300_cit43","doi-asserted-by":"publisher","first-page":"59","DOI":"10.1016\/j.jcis.2018.08.045","article-title":"Microfluidic\nProduction of Size-Tunable Hexadecane-in-Water Emulsions: Effect of\nDroplet Size on Destabilization of Two-Dimensional Emulsions Due to\nPartial Coalescence","volume":"533","author":"Abedi","year":"2019","journal-title":"J. Colloid Interface Sci."},{"issue":"1","key":"2026100809091656300_cit44","doi-asserted-by":"publisher","first-page":"283","DOI":"10.1021\/acscatal.0c04360","article-title":"Nadh Regeneration:\nA Case Study of Pt-Catalyzed NAD+ Reduction\nwith H2","volume":"11","author":"Saba","year":"2021","journal-title":"ACS Catal."},{"issue":"6","key":"2026100809091656300_cit45","doi-asserted-by":"publisher","first-page":"5486","DOI":"10.1021\/acscatal.9b00513","article-title":"Efficient\nNADH Regeneration by a Redox Polymer-Immobilized Enzymatic System","volume":"9","author":"Yuan","year":"2019","journal-title":"ACS Catal."}],"container-title":["The Journal of Physical\nChemistry B"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pubs.acs.org\/doi\/pdf\/10.1021\/acs.jpcb.6c04531","content-type":"application\/pdf","content-version":"vor","intended-application":"unspecified"},{"URL":"https:\/\/pubs.acs.org\/jpcbfk\/article-pdf\/130\/40\/10438\/68702655\/acs.jpcb.6c04531.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/pubs.acs.org\/jpcbfk\/article-pdf\/130\/40\/10438\/68702655\/acs.jpcb.6c04531.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,10,8]],"date-time":"2026-10-08T13:09:26Z","timestamp":1791464966000},"score":1,"resource":{"primary":{"URL":"https:\/\/pubs.acs.org\/jpcbfk\/article\/130\/40\/10438\/5441829\/Study-on-the-Methyl-Viologen-Mediated"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,29]]},"references-count":45,"journal-issue":{"issue":"40","published-online":{"date-parts":[[2026,9,29]]},"published-print":{"date-parts":[[2026,10,8]]}},"URL":"https:\/\/doi.org\/10.1021\/acs.jpcb.6c04531","relation":{},"ISSN":["1520-6106","1520-5207"],"issn-type":[{"value":"1520-6106","type":"print"},{"value":"1520-5207","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,29]]}}}