One-step aqueous synthesis of CdS nanoparticles as a novel fluorescence probe for the ultrasensitive detection of DNA

One-step aqueous synthesis of CdS nanoparticles as a novel fluorescence probe for sensitive and selective determination of DNA with synchronous fluorescence spectrometric method has been developed. Different from the traditional organometallic route, in which toxic precursors or solvents might be used, the wet chemical approach demonstrated in this paper is superior in terms of simplicity, using of nontoxic materials, mild synthetic condition and good reproducibility. When Δλ=255 nm, maximum synchronous fluorescence is produced at 264 nm, the synchronous fluorescence intensity of the composite nanoparticles is significantly decreased in the presence of trace DNA at PH 0.91. Under optimal conditions, the linear ranges of the calibration curves are 0.08-30.0 μg mL−1 for ctDNA and 0.05-35.0 μg mL−1 for hsDNA, respectively. The detection limits are 1.5 ng mL−1 for ctDNA and 2.2 ng mL−1 for hsDNA, respectively. Furthermore, the method is successfully applied to the quantification of DNA in synthetic samples. The results show that this proposed method is stable, sensitive and practical for the determination of trace DNA.