1. A label-free and double recognition–amplification novel strategy for sensitive and accurate carcinoembryonic antigen assay.
- Author
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Liu, Zi, Lei, Sheng, Zou, Lina, Li, Gaiping, Xu, Lingling, and Ye, Baoxian
- Subjects
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CARCINOEMBRYONIC antigen , *DNA probes , *DETECTION limit , *SIGNAL processing , *NUCLEIC acid hybridization - Abstract
Abstract Herein, a label-free and double recognition–amplification (LDRA) strategy for carcinoembryonic antigen (CEA) detection was developed, based on a new designed dual-function messenger probe (DMP) coalescing with DNA tetrahedron probes (DTPs) and hybridization chain reaction (HCR). The DMP possess dual-function to replace CEA for specific interface hybridization and initiate hybridization chain reaction. The interfacial hybridization event was quantitatively converted to an electrochemical signal by using hemin/G-quadruplex (h-Gx) formed after the hybridization chain reaction. Self-assembled DNA tetrahedron probes, which were readily decorated on an electrode surface as a scaffold with rigid support and ordered orientation, enabled the highly efficient strands hybridization and greatly increased target accessibility as well as significantly decreased noise. The proposed assay integrated dual recognition processes and HCR signal amplification processes, achieving the identification of low concentration of CEA as detection limit of 18.2 fg mL−1 (S/N = 3) and wider linearity range of 0.0001 ng mL−1–50 ng mL−1. A new electrochemical sensing method was proposed for CEA detection and used in real clinical samples. The obtained results were good consistency with those of clinical diagnosis. Highlights • A new dual-function messenger probe (DMP) was designed for specific interface hybridization and initiate HCR. • The employment of DNA tetrahedron probes increased the probability of hybridization and reduced the background signal. • The synergetic combination of DMP and hybridization chain reaction (HCR) improved the sensitivity of the detection. • The proposed strategy was used to analysis CEA in real sample and achieved a detection limit as low as 18.2 fg/mL. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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