A label-free method for detecting biothiols based on poly(thymine)-templated copper nanoparticles

A novel label-free nanosensor has been developed for detecting biothiols including cysteine, glutathione and homocysteine based on poly(thymine)-templated fluorescent copper nanoparticles (CuNPs), which were controlled through thymine-Hg(II)-thymine coordination. This assay provides a simple, cost-effective, and sensitive platform for the detection of biothiols. By employing this turn-on sensor, biological thiols, such as cysteine, glutathione and homocysteine, are successfully detected at concentrations as low as 12.5 nM for cysteine, 15 nM for glutathione, and 20 nM for homocysteine. The sensing system also exhibits high selectivity against other amino acids, and the application of the sensor for biological fluids shows that the proposed method works well for real samples.