Resonance light scattering determination of uranyl based on labeled DNAzyme–gold nanoparticle system

•A novel RLS method based on DNAzyme and AuNPs was developed for detection of UO22+.•The method has advantages of requiring simple instrument, having high selectivity and lower limit of detection.•The proposed RLS mechanism is benefit to extend the application of DNAzyme–AuNPs.

A resonance light scattering (RLS) method has been developed using a uranyl (UO22+) specific DNAzyme and gold nanoparticles (AuNPs). In this strategy, the cleavage of the substrate strand (SDNA) of DNAzyme results in releasing a shorter duplex in the presence of UO22+, leading to the aggregation of AuNPs and the increase of RLS intensity. The response signals linearly correlated with the concentration of UO22+ over the range of 1.36 × 10−8–1.50 × 10−7 mol L−1. The limit of detection (LOD) is 4.09 × 10−9 mol L−1. The method has excellent selectivity and higher sensitivity. It could provide a promising potential for the detection of metal ions, and be benefit to extend the application of RLS method.

Graphical abstractA uranyl-specific DNAzyme was attached to AuNPs. Upon addition of UO22+, the shorter duplex constructed by the fragment after cleavage of SDNA with EDNA is released, decreasing the stability of AuNPs.Figure optionsDownload full-size imageDownload as PowerPoint slide