Directly light scattering imaging of the aggregations of biopolymer bound chromium(III) hydrolytic oligomers in aqueous phase and liquid/liquid interface

Investigations of inorganic oligomers are important in both chemistry and physiology. In this contribution, we propose a laser induced light scattering imaging (LSI) and a total internal reflected light scattering imaging (TIR-LSI) technique, and apply them to characterize the interactions of inorganic oligomers with biopolymer in aqueous phase and at liquid/liquid interface, respectively. In aqueous medium, synthetic chromium(III) hydrolytic oligomers (CrHO) react with DNA, and the resultant binary could be extracted into the H2O/CCl4 interface in the presence of triocyctyl phosphine oxide (TOPO), forming a DNA-CrHO-TOPO ternary amphipathic complex at the interface with the associate constant of 1.32 × 103 mol−1 dm4 for a given 1.0 × 10−4 mol l−1 TOPO. Under the excitation of a 441-nm He-Cd laser light beam, the resultant light scattering and total internal reflected light scattering (TIR-LS) signals of the formed binary in aqueous phase and ternary at liquid/liquid interface could be easily captured using a common microscope coupled with a CCD camera. By digitally analyzing the CCD captures, we demonstrate that aggregations of the CrHO-DNA binary in aqueous phase and DNA-CrHO-TOPO ternary at liquid/liquid interface have occurred, respectively.