An improved setup including a measuring cell was designed for time-resolved surface-enhanced resonance Raman (SERR) spectroscopy. The cell is based on a rotating disk electrode (RDE) made from electrochemically roughened Ag. Cytochrome c (cc) adsorbed on a monolayer of mercaptoethanol is investigated with respect to heterogeneous electron transfer. Cyclic voltammograms and potential-dependent static SERR spectra indicate cc to be electroactive on the Ag electrode. The standard redox potential was found to be 234 mV. Time-resolved SERR spectra were then measured triggered by periodic potential pulses changing the protein between the oxidized and reduced state at a frequency of 10 Hz. Monoexponential functions obtained from the intensity of the band at 1361 cm-1 plotted versus time yielded the rate constants of heterogeneous electron transfer to be k(ox) = 46 +/- 7 s(-1) and k(red) = 84 +/- 20 s(-1). These relatively low rates are in line with the orientation of cc on the mercaptoethanol-modified Ag electrode. In this case the heme cleft pointed away from the surface thus hampering electron transfer.
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http://dx.doi.org/10.1021/jp808865z | DOI Listing |
J Colloid Interface Sci
April 2025
State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640, China. Electronic address:
Conventional light-driven antimicrobial strategies of zinc oxide (ZnO) are limited by inadequate illumination in dark environments. In this study, carboxylated cellulose nanocrystals (MCNC) mediated flower-like ZnO (C@Z) with self-promoted reactive oxygen species release under dark is fabricated. The adsorption of Zn ions on MCNC prompts the growth of ZnO along the (002) crystal plane, forming a flower-like hybrid with superior dispersibility and oxygen vacancies compared to MCNC-free ZnO, which exposes the (100) plane.
View Article and Find Full Text PDFAnal Chim Acta
February 2025
School of Chemistry and Chemical Engineering, University of Jinan, Jinan, 250022, PR China; Department of Chemistry, Sungkyunkwan University, Suwon, 16419, Republic of Korea. Electronic address:
Background: Estriol (E3) is a common estrogen responsible for regulating the female reproductive system, but excessive amount can pose health risks to humans and wild life. Therefore, sensitive and accurate detection of estriol level is crucial. A novel competitive ECL immunosensor based on a dual signal amplification strategy of AuNPs@GO@SmMoSe and Gd(MoO) was fabricated for ultrasensitive detection of estriol.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar 161006, PR China; Heilongjiang Provincial Key Laboratory of Catalytic Synthesis for Fine Chemicals, Qiqihar University, Qiqihar 161006, PR China. Electronic address:
The establishment of heterojunctions has been demonstrated as an effective method to improve the efficiency of photocatalytic hydrogen production. Conventional heterojunctions usually have random orientation relationships, and heterointerfaces can hinder photogenerated carrier transport due to larger lattice mismatches, thus reducing the photoelectric conversion efficiency. In this study, a novel Te/InO@MXene lattice coherency heterojunction was prepared by leveraging the identical lattice spacing of InO (222) and Te (021) crystal face.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
College of Materials Science and Engineering, Hunan University, Changsha 410082 PR China. Electronic address:
Although MXenes have attracted significant attention across diverse fields, they exhibit a pronounced susceptibility to oxidation in aqueous environments, with oxidation significantly accelerated in the presence of transition metal ions (TMI) such as Fe and Cu. This limitation impedes the synthesis of transition metal compounds/MXene-based composites and their potential for functional applications. In this study, we elucidate the mechanism of accelerated oxidation of TiCT is that Fe promotes the electron loss in TiCT, thus leading to an increased production of hydroxyl radicals (OH) to oxidize TiCT.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2025
School of Chemistry, Dalian University of Technology, Dalian 116024 PR China. Electronic address:
The development of electrode materials for aqueous ammonium-ion supercapacitors (NH-SCs) has garnered significant attention in recent years. Poor intrinsic conductivity, sluggish electron transfer and ion diffusion kinetics, as well as structural degradation of vanadium oxides during the electrochemical process, pose significant challenges for their efficient ammonium-ion storage. In this work, to address the above issues, the core-shell VO·nHO@poly(3,4-ethylenedioxithiophene) composite (denoted as VOH@PEDOT) is designed and prepared by a simple agitation method to boost the ammonium-ion storage of VO·nHO (VOH).
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