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Updated: Aug 17, 2025
Fabrication of Electrochemical-DNA Biosensors for the Reagentless Detection of Nucleic Acids, Proteins and Small Molecules
Published on: June 1, 2011
A dual-modal electrochemical aptasensor based on intelligent DNA Walker with cascade signal amplification powered by
Yue Wang1, Hongguo Zhai1, Qi Guo1
1School of Agricultural Engineering and Food Science, Shandong University of Technology, No. 266 Xincun Xilu, Zibo 255000, China; Shandong Province Engineering Research Center of Vegetable Safety and Quality Traceability, No. 266 Xincun Xilu, Zibo 255000, China; Zibo City Key Laboratory of Agricultural Product Safety Traceability, No. 266 Xincun Xilu, Zibo 255000, China.
Abstract:
As a unique nanomachine, DNA Walker can move continuously along a specific orbit to amplify signal. Therefore, based on DNA Walker and endonuclease assisted signal amplification strategy, a novel dual-mode visual electrochemical aptasensor was constructed for the detection of Pb2+. Ceric dioxide@mesoporous carbon (CeO2/CS)@AuNPs not only could improve the conductivity of sensing interface but also could fix the aptamer. DNA Walker moved on the surface of the electrode to realize the pairing with the Ag-γFe2O3/cDNA probe, forming a special base sequence that could be spliced by the Nb.BbvCI. Under the action of endonuclease Nb.BbvCI, the Ag-γFe2O3/cDNA probe was continuously sheared and the amount on the electrode was decreased to amplify the signal. Besides, the nanoenzyme of Ag-γFe2O3 could catalyze 3'3'5'5'-tetramethylbenzidine (TMB) to blue color realizing the visual detection of Pb2+. The sensor has been successfully applied to the visual and accurate rapid detection of Pb2+ in aquatic products. The fabricated method of the sensor open up a new way for visual and accurate the detection of environmental pollutants.
