Circular Dichroism

Circular dichroism (CD) is the differentialabsorption of left- and right-handed circularlypolarized light. This phenomenon is exhibited in theabsorption bands of optically active molecules andnanoparticles. Magnetic CD spectroscopy serves as anexcellent tool to track and control the distributionof ions within the spinel lattice of ferritenanoparticles assisting in the development of generalpreparation schemes of stoichiometrically controlledmulti-cation oxide nanocrystals. The correlationbetween natural circular dichroism and plasmonicsgives rise to two different phenomena. An enhanced CDsignal is obtained when chiral molecules are adsorbedonto noble metal nanoparticles enabling thedevelopment of a highly sensitive semi-analyticaltechnique similar to other enhanced spectroscopictechniques (e.g. SERS SEIRA SEF SEMO). The growthof silver nanoparticles in a DNA scaffold resulted ina rather surprising discovery that the nanoparticleswere in fact chiral.