Label-free and sensitive assay for deoxyribonuclease I activity based on enzymatically-polymerized superlong poly(thymine)-hosted fluorescent copper nanoparticles

By seamlessly integrating the special functions of deoxyribonuclease I (DNase I) and terminal deoxynucleotidyl transferase (TdT), a novel fluorescent sensor for DNase I activity has been developed based on superlong poly(thymine)-hosted copper nanoparticles (poly T-CuNPs). The strategy is green, facile, cost-effective, label-free and highly-sensitive, thus achieving a limit of detection as low as 0.02 U/mL and potential applicability to biological samples.156