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Updated: Aug 11, 2026

Characterization of pH-Dependent Reversible Self-Assembly of Amyloid Beta 1-40-Coated Gold Colloids
Published on: March 21, 2025
Synthesis and optical property of beta-brass colloid
1Henkel Research Center of Advanced Technology, Molecular Institute, Kinki University, 11-6, Kayanomori, Iizuka, Fukuoka 820-8555, Japan. acn12420@par.odn.ne.jp
Abstract:
Cu/Zn beta-phase alloy (beta-brass) colloid was successfully synthesized by reducing the organometallic complexes in the organic liquid phase. It was confirmed by X-ray diffraction that the material formed pure beta-phase. The morphology for the beta-brass particles was observed using transmission electron microscopy (TEM). The dispersion of the particle diameter was almost single modal, and the diameter was estimated at 8+/-2 nm. A clear peak around 520 nm was seen in the optical absorption spectrum for the beta-brass colloid, and it is attributed to the surface plasmon absorption. We also simulated the optical absorption spectrum using the bulk dielectric constant for beta-brass. The simulation qualitatively reproduced the experimental data well.
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Properties of Enantiomers and Optical Activity
Stereoisomerism
Isomers are different chemical species that have the same chemical formula.
Transition metal complexes often exist as geometric isomers, in which the same atoms are connected through the same types of bonds but with differences in their orientation in space. Coordination complexes with two different ligands in the cis and trans positions from a ligand of interest form isomers. For example, the octahedral [Co(NH3)4Cl2]+ ion has two isomers (Figure 1) In the cis...
Colloids

