Single-Nanoparticle ICP-MS for Sensitive Detection of Uracil-DNA Glycosylase Activity.

Single-nanoparticle inductively coupled plasma mass spectrometry (SP-ICP-MS) has demonstrated unique advantages for the detection of biological samples. However, methods for enzyme activity detection based on SP-ICP-MS technology have been rarely explored. Here we report the development of a novel SP-ICP-MS assay for uracil-DNA glycosylase (UDG) activity detection based on its ability to specifically recognize and remove uracil to induce the cleavage of the DNA probe. Our design allows the generation of single gold nanoparticles correlated to the specific enzymatic reaction for a highly sensitive SP-ICP-MS measurement. The developed assay enables sensitive UDG activity detection with a detection limit of 0.0003 U/mL. The cell lysate analysis by the developed assay reveals its applicability for the detection of UDG activity in real samples. It is envisioned that our design may provide a new paradigm for developing the SP-ICP-MS assay for enzyme activity detection in biological samples.