Voltammetry plays a crucial role in modern scientific research by offering valuable insights into the electrochemical properties of materials, with wide-ranging applications in fields such as... Show moreVoltammetry plays a crucial role in modern scientific research by offering valuable insights into the electrochemical properties of materials, with wide-ranging applications in fields such as materials science, energy storage, corrosion studies, and sensor development.Gold, known for its exceptional inertness, provides a unique platform for studying intricate electrochemical processes due to its stability and slow electrochemical behavior. However, certain questions regarding gold voltammetry have remained unresolved throughout history. To address these gaps, our research employed a combination of electrochemical cyclic voltammetry and advanced in situ techniques like surface-enhanced Raman spectroscopy (SERS), Rotating ring-disk electrode (RRDE), and Electrochemical quartz crystal microbalance (EQCM).Through our investigations, we not only redefined the mechanism of gold oxide formation but also uncovered the reasons behind the structural reconstruction of gold oxide. Additionally, we elucidated the electrochemical interfacial structure on gold from a novel perspective focusing on charge distribution.The significance of these findings lies in their fundamental nature, with the potential to inspire researcher to reconsider interpretations of voltammetry behaviors across various materials and research fields. We anticipate that our work will stimulate further exploration and innovation in the realm of electrochemistry, paving the way for new discoveries and advancements. Show less
Multicopper oxidase, laccase, can efficiently reduce oxygen to water and are mostly used in the enzymatic biofuel cells. However, they suffer from low stability when functionalized over an... Show moreMulticopper oxidase, laccase, can efficiently reduce oxygen to water and are mostly used in the enzymatic biofuel cells. However, they suffer from low stability when functionalized over an electrode. This can be overcome by designing artificial catalysts for the oxygen reduction reaction based on the active site of laccase which requires a detailed understanding of the active site. The current research is aimed at characterizing the active site of small laccase from Streptomyces coelicolor using a combination of paramagnetic NMR spectroscopy, EPR spectroscopy, mutagenesis and quantum mechanical (QM) calculations. The presence of chemical exchange at the active site of laccase attributed to the coordinating histidines is reported. QM calculations showed the importance of the orientation of the coordinating water derived ligand. Mutagenesis study showed the importance of second shell residue in stabilizing intermediates during the oxygen reduction reaction. It is also reported that by changing the pH, a new intermediate could be experimentally observed however, further research is needed to characterize this. The resonance assignment shown in the current research can be used as spies to characterize the active site of laccase. This might in future provide insight into the catalytic mechanism of oxygen reduction reaction by laccase. Show less
