Magnetless Device for Conducting Three‐Dimensional Spin‐Specific Electrochemistry

Electron spin states play an important role in many chemical processes. Most spin‐state studies require the application of a magnetic field. Recently it was found that the transport of electrons through chiral molecules also depends on their spin states and may also play a role in enantiorecognition. Electrochemistry is an important tool for studying spin‐specific processes and enantioseparation of chiral molecules. A new device is presented, which serves as the working electrode in electrochemical cells and is capable of providing information on the correlation of spin selectivity and the electrochemical process. The device is based on the Hall effect and it eliminates the need to apply an external magnetic field. Spin‐selective electron transfer through chiral molecules can be monitored and the relationship between the enantiorecognition process and the spin of electrons elucidated.     

Tip‐Enhanced Raman Spectroscopy to Distinguish Toxic Oligomers from Aβ1–42 Fibrils at the Nanometer Scale

For the first time, natural Aβ_1–42 fibrils (WT) implicated in Alzheimer's disease, as well as two synthetic mutants forming less toxic amyloid fibrils (L34T) and highly toxic oligomers (oG37C), are chemically characterized at the scale of a single structure using tip‐enhanced Raman spectroscopy (TERS). While the proportion of TERS features associated with amino acid residues is similar for the three peptides, a careful examination of amide I and amide III bands allows us to clearly distinguish WT and L34T fibers organized in parallel β‐sheets from the small and more toxic oG37C oligomers organized in anti‐parallel β‐sheets.