Abstract:

In recent years, Rayleigh light scattering has become a new tool for determining the content of biological molecules and studying the interaction mechanism of organic dyes with biological molecules^[1]. According to the macroscopic fluctuation theory, in a transparent isotropic medium, when the light scattering is caused by molecular particles 20-fold smaller than the wavelength of the incident beam, the Rayleigh scattering law is obeyed, namely I∝1/λ^4[2]. However, if the wavelength of the incident beam is close to that of the absorption band of the molecular particles which exist as aggregates, Rayleigh scattering will deviate from the law and enhanced RLS can be expected^[3]. Using this technique, a method for the determination of proteins in aqueous solution has been developed based on the enhancement effect of proteins on die Rayleigh light scattering (RLS) of organic dyes^[4].