Magneto-controlled Quantized Electron Transfer to Surface-confined Redox Units and Metal Nanoparticles

Sensors

Eugenii Katz¹ 

关键词: Nanoparticles;    magnetic particles;    quantum charging;    modified electrode;    switchable interface;   

DOI  :  10.3390/s6040420

来源: mdpi

【 摘 要 】

Hydrophobic magnetic nanoparticles (NPs) consisting of undecanoate-capped magnetite (Fe₃O₄, average diameter ca. 5 nm) are used to control quantized electron transfer to surface-confined redox units and metal NPs. A two-phase system consisting of an aqueous electrolyte solution and a toluene phase that includes the suspended undecanoate-capped magnetic NPs is used to control the interfacial properties of the electrode surface. The attracted magnetic NPs form a hydrophobic layer on the electrode surface resulting in the change of the mechanisms of the surface-confined electrochemical processes. A quinone-monolayer modified Au electrode demonstrates an aqueous-type of the electrochemical process (2e^-+2H⁺ redox mechanism) for the quinone units in the absence of the hydrophobic magnetic NPs, while the attraction of the magnetic NPs to the surface results in the stepwise single-electron transfer mechanism characteristic of a dry non-aqueous medium. Also, the attraction of the hydrophobic magnetic NPs to the Au electrode surface modified with Au NPs (ca. 1.4 nm) yields a microenvironment with a low dielectric constant that results in the single-electron quantum charging of the Au NPs.

【 授权许可】

Unknown   
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