A Label-free Time-resolved Luminescent Platform for Sensitive Endonuclease V Detection Based on Exonuclease III Regulated DNA-Tb3+ Luminescence

Abstract

Endonuclease V (EndoV) plays the important role of nucleotide excision repair (NER) in the maintenance of genomic stability. Highly sensitive detection of EndoV was achieved through an oligonucleotides sensitizing Tb luminescent technique. We found that although both guanine-rich (G-rich) single-stranded DNA and dGMP could enhance the time-resolved luminescence of Tb, their efficiencies of enhancement were considerably different. Employing such interesting phenomenon, a label-free and time-resolved luminescent strategy for the sensitive detection of EndoV activity was developed based on DNA-enhanced time-resolved luminescence (TRL) of Tb. The EndoV was used to cut off the deoxyinosine site (dI) and convert the 3'-protruding termini to a recessed end, and Exonuclease III (Exo III) was used to enhance the signal contrast via digestion of G-rich DNA to dNTP. Combining with the natural advantages of the TRL, the proposed method exhibited a good linear response to EndoV ranging from 0.005 to 0.4 U/mL, with a low limit of detection of 0.005 U/mL.

DNA-based Fluorescent Sensors

“…Fluorescent sensing strategies for target DNA 13 and Hg 2+ , 14 which are based on the use of NMM and Exo III, were reported. An endonuclease V (Endo V) sensing method using Exo III, 15 and a fluorescent sensor for K + using exonuclease I (Exo I), 16 were also developed. In addition, other DNA-based fluorescent sensors were also reported.…”