Enzyme-free and triple-amplified electrochemical sensing of 8-hydroxy-2'-deoxyguanosine by three kinds of short pDNA-driven catalyzed hairpin assemblies followed by a hybridization chain reaction
Autor: | Lei Shang, Li-Ping Jia, Ruo-Nan Zhao, Wen-Li Jia, Rong-Na Ma, Huaisheng Wang, Zhe Feng, Wei Zhang |
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Rok vydání: | 2020 |
Předmět: |
Detection limit
Concatemer Aptamer Inverted Repeat Sequences 8-Hydroxy-2'-deoxyguanosine Nucleic Acid Hybridization Biosensing Techniques DNA Aptamers Nucleotide Electrochemistry Biochemistry Combinatorial chemistry Analytical Chemistry Catalysis chemistry.chemical_compound chemistry 8-Hydroxy-2'-Deoxyguanosine Electrode Biocatalysis Environmental Chemistry Humans Spectroscopy |
Zdroj: | The Analyst. 145(10) |
ISSN: | 1364-5528 |
Popis: | A sensitive and enzyme-free electrochemical aptasensor was constructed for the sensing of 8-hydroxy-2′-deoxyguanosine (8-OH-dG). In the process of constructing the aptasensor, triple signal amplification strategies were introduced to enhance the sensitivity. First, every aptamer/pDNA complex immobilized on magnetic beads could release three kinds of pDNAs when 8-OH-dG was introduced, which caused three-fold magnification of the target. Second, the released three kinds of pDNAs initiated catalyzed hairpin assembly between two hairpin DNAs (HP1 and HP2) on a gold electrode. Meanwhile, the three kinds of pDNAs were released again by a strand displacement reaction to obtain the next catalyzed hairpin assembly. Third, the emerging toehold of HP2 further induced a hybridization chain reaction (HCR) between two hairpin DNAs (HP3 and HP4), forming a long double-stranded DNA concatemer on the surface of the electrode. Finally, [Ru(NH3)6]3+, an electroactive cation, was adsorbed onto the long dsDNA concatemer by electrostatic interactions and consequently, an electrochemical signal was generated. Under this triple signal amplification, a low detection limit down to 24.34 fM has been obtained for 8-OH-dG determination, which is superior to those of most previously reported methods. |
Databáze: | OpenAIRE |
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