A zeta potential-based homogeneous assay for amplified detection of telomerase in cancer cells

Telomerase is a potential tumor biomarker, which is overexpressed in various types of tumor cells. Herein, we describe a zeta potential-based assay for homogeneous and amplified detection of telomerase activity. To do so, a peptide nucleic acid-modified antifouling nanocomplex (PNA-ANC) and ultralong DNA chains are prepared. In the presence of telomerase, the enzyme will add telomeric sequences on its substrates attached on the DNA chains. Thus, the DNA chains can specifically bind to PNA-ANCs via PNA-DNA hybridization, which brings thousands of negatively charged nucleotides on the ANCs and results in dramatic potential change. Combination of zwitterionic PNA-ANCs and highly negatively charged DNA chains, the signal-to-noise ratio of this assay is significantly improved, allowing amplified detection of telomerase with a limit of detection of 3 nasopharynx cancer cells. Moreover, thanks to the potential technique and prefabricated DNA chains, the detection procedure is simple and time-saving, making it potential to be a technological innovation in the field of telomerase analysis.