Novel colorimetric assay of LSD1 activity using gold nanoparticles

We have developed a simple and sensitive strategy for colorimetric LSD1 enzyme activity assay using avidin modified gold nanoparticles. The strategy is based on the vivid color change of a gold nanoparticle solution from red to violet upon addition of a test solution of peptide-antibody treated with LSD1. Thus, the presence of LSD1 in a sample can be determined by simple visual inspection with the naked eye. In addition, a wide range of LSD1 concentrations (13 pM to 0.13 mu M) were quantitatively determined by spectrophotometry, which shows the possibility of quantitative analysis of the over expression levels of LSD1 in cancer tissue samples.