Applications Of Resonance Light Scattering Technique In Determination Of Trace Biomacromolecule

The common analytical technique of determination for biomacromolecules mainlyinclude fluorimetry and spectrophometry in1990s, but both of the two methods havesome serious disadvantages. Fluorimetry is restricted by fluorimetry probes and somefluorimetry reagents are expensive and toxic, so it isn’t suitable for widely application.Spectrophometry suffers from low sensitivity, disturbance and consuming time. Andthen a technique that have convenient operation, simple instrument, high sensitivity,types of probes cames out, which is called after Resonance Light Scattering （RLS）. Somore and more researchers turn to determine biomacromolecules such as nucleic acid,carbohydrates, and proteins by RLS.DNA combines with small molecules by three modes: intercalative binding, groovebinding and electrostatic force. Surfactant could enhance surface activity of solution andsensitize intensity of resonance light scattering, and combine with DNA by electrostaticforce. Surfactant have been used to determine DNA as a probe long before, andtherefore resonance light scattering spectrometry is applied in this study.In this paper, a detailed research of RLS technique is considered, kinds of simple,rapid, sensitive probes which are used to determine for salmon sperm DNA are set up.Active components in Chinese herb （flavonoids, such as naringenin, hesperetin,apigenin）-CTAB are used as probes to determine DNA. The investigation illustrates thatsurfactants act as a bridge and bind with DNA and the dissociated active componentsChinese herb in the ternary system, then ternary complexes form that cause theenhancement of RLS signal. DNA could enhance the weak RLS signal offlavonoids-CTAB under the optimal experiment conditions, and the enhanced light scattering intensity is proportional to the concentration of DNA. For theDNA-CTAB-naringenin system, the enhanced RLS intensity at353nm is proportionalto the content of DNA in the range of0.017-1.7μg mL^-1. The linear regression equationis IRLS1.3943.3C(C, μg mL^-1). The correlation coefficient r is0.994. Thedetection limit is5.06ng mL^-1. The recovery is99.3-105.0%and RSD is0.7-3.7%.For the DNA-CTAB-hesperetin system, the enhanced RLS intensity at363nm isproportional to the content of DNA in the range of0.022-4.4μg mL^-1. The linearregression equation is IRLS3.11289.025C(C, μg mL^-1). The correlationcoefficient r is0.998. The detection limit is2.34ng mL^-1. The recovery is97.3-101.9%and RSD is0.54-1.16%.For the DNA-CTAB-apigenin system, the enhanced RLS intensity at433nm isproportional to the content of DNA in the range of0.013-4.4μg mL^-1. The linearregression equation is IRLS5.6448.086C(C, μg mL^-1). The correlationcoefficient r is0.998. The detection limit is2.97ng mL^-1. The three methods have beensuccessfully applied to the determination of DNA in synthetic samples. The recovery is101.2-109.5%and RSD is1.82-4.74%.The different dissociation ways of emodin that is part of anthraquinones are studiedin weak acid and base solution and emodin-CPB is used as a probe of the determinationfor DNA. CPB bind DNA and emodin by electrostatic attraction and enhance the RLSsignal obviously. Under the optimal conditions, the I RLSat340nm is proportional tothe content of DNA in the range of0.01-2.72μg mL^-1. The linear regression equation isIRLS28.68118.35C(C, μg mL^-1). The correlation coefficient r is0.9923. Thedetection limit is1.5ng mL^-1. The recovery is97.6-107.3%and RSD is3.8-5.2%.