A DNAzyme-catalyzed label-free aptasensor based on multifunctional dendrimer-like DNA assembly for sensitive detection of carcinoembryonic antigen
| Autor: | Qi-Yan Lv, Xiaojie Song, Xiao-Jing Zhai, Yongjun Guo, Qiong-Lin Wang, Hui-Fang Cui |
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| Rok vydání: | 2021 |
| Předmět: |
Dendrimers
Aptamer Biomedical Engineering Biophysics Deoxyribozyme Biosensing Techniques G-quadruplex Catalysis chemistry.chemical_compound Carcinoembryonic antigen DNA nanotechnology Electrochemistry Humans biology Chemistry Reproducibility of Results General Medicine DNA DNA Catalytic Aptamers Nucleotide Molecular biology Carcinoembryonic Antigen Linear range biology.protein Differential pulse voltammetry Biotechnology |
| Zdroj: | Biosensorsbioelectronics. 194 |
| ISSN: | 1873-4235 |
| Popis: | Carcinoembryonic antigen (CEA) is an important malign tumor marker. In this study, a simple, label-free and antibody-free aptasensor was fabricated based on a multifunctional dendrimer-like DNA nanoassembly. The DNA nanoassembly was embedded with multiple G-quadruplex DNAzyme motifs and a hanging CEA aptamer motif. It was prepared from short DNA sequences by autonomous-assembly. The aptasensor was prepared simply by self-assembly of a capture DNA (cpDNA) on a gold electrode, followed by hybridization with a CEA aptamer (AptGAC-P). CEA as a model target was detected through competitive binding of CEA with AptGAC-P, exposing cpDNA to bind with the DNA nanoassembly. The detection process only contains 2 incubation steps. The high load of G-quadruplex DNAzyme motifs and their catalytic activity resulted in an amplified and label-free differential pulse voltammetry (DPV) electrochemical signal. The peak current correlated linearly with the CEA concentration, with a linear range of 2–45 ng mL−1, and an LOD value of 0.24 ng mL−1. The aptasensor showed high specificity and reproducibility, and retained 96.5% of detection signal intensities after 31 days of storage. The recovery rates for spiked CEA in human serum were within 100 ± 5%, and the coincidence rates for clinical human serum samples with ELISA kits were 80.7–111%. Conceivably, possessing simplicity, sensitivity, reproducibility, storage stability, and accuracy, the aptasensor should be a very prominent and applicable tool for clinical CEA detection and cancer diagnosis, and is promisingly applicable as a platform for detecting other targets of interests. |
| Databáze: | OpenAIRE |
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