Application of L-Cys-Capped CdS Nanoparticles in Determination of Nucleic Acid by Resonance Light-Scattering Technique

摘要

Aim To determine nucleic acid (DNA) using Nanometer-sized L-cysteine-capped CdS particles by resonance light scattering (RLS) method. Methods The nano-particles synthesized by a colloidal aqueous method were water-soluble, stable, and highly luminescent. The RLS of L-Cys-CdS particles were greatly quenched by DNA in Tris-HCl solutions. The intensity of RLS at 344 nm was proportional to the concentration of DNA. Results The linearity range of the calibration curve was 0.01 -1.0 μg·mL~(-1) for calf thymus DNA and 0.04 - 1.5 μg·mL~(-1) for salmon sperm DNA. The detection limits (3 δ) were 8 ng·mL~(-1) for calf thymus DNA and 10 ng·mL~(-1) for salmon sperm DNA. Conclusion This method is simple, sensitive, and capable of avoiding the use of toxic dyes.