Dual signal amplification by polysaccharide and eATRP for ultrasensitive detection of CYFRA 21–1 DNA

Publication date: Available online 15 November 2019Source: Biosensors and BioelectronicsAuthor(s): Liying Zhao, Huaixia Yang, Xiaoke Zheng, Jinge Li, Lihe Jian, Weisheng Feng, Jinming KongAbstractCytokeratin fragment antigen 21–1 (CYFRA 21–1) DNA is a crucial biomarker closely associated with non-small cell lung cancer. Here, we fabricated a novel electrochemical biosensor for ultrasensitive detection of CYFRA 21–1 DNA via polysaccharide and electrochemically mediated atom transfer radical polymerization (eATRP) dual signal amplification. Specifically, thiolated peptide nucleic acid (PNA) probes at 5′-terminals are immobilized on the gold electrode surface for specific recognition of CYFRA 21–1 DNA (tDNA). After hybridization, hyaluronic acid (HA) is linked to the hybridized PNA/DNA duplexes via the recognized carboxylate-Zr4+-phosphate chemistry. Then multiple initiators of the polymerization reaction are introduced via esterification reaction. Lastly, large numbers of electro-active monomers are successfully grafted from the initiation sites of functionalized HA by eATRP reaction, significantly amplifying the electrochemical signal. Under optimal conditions, the constructed sensor can detect as low as 9.04 aM tDNA. Further, this proposed biosensor can also be applied to the direct detection of double-stranded DNA (dsDNA), obtaining 0.12 fM as the detection limit. Besides, this strategy shows high selectivity for mismatched bases and excellent applicability for C...
Source: Biosensors and Bioelectronics - Category: Biotechnology Source Type: research