Electrochemical sensor based on Fe3O4/α-Fe2O3@Au magnetic nanocomposites for sensitive determination of the TP53 gene.

Ruijiang Liu, Yanling Zhang, Min Liu, Yun Ni, Yao Yue, Shaobo Wu, Shasha Li

Bioelectrochemistry (Amsterdam, Netherlands) 2023 Aug

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Considering the high cost and tedious process of gene sequencing, there is an urgent need to develop portable and efficient sensors for the TP53 gene. Here, we developed a novel electrochemical sensor that detected the TP53 gene using magnetic peptide nucleic acid (PNA)-modified Fe3O4/α-Fe2O3@Au nanocomposites. Cyclic voltammetry and electrochemical impedance spectroscopy confirmed the successful stepwise construction of the sensor, especially the high-affinity binding of PNA to DNA strands, which induced different electron transfer rates and resulted in current changes. Variations in the differential pulse voltammetry current observed during hybridization at different surface PNA probe densities, hybridization times, and hybridization temperatures were explored. The biosensing strategy obtained a limit of detection of 0.26 pM, a limit of quantification of 0.85 pM, and a wide linear range (1 pM-1 μM), confirming that the Fe3O4/α-Fe2O3@Au nanocomposites and the strategy based on magnetic separation and magnetically induced self-assembly improved the binding efficiency of nucleic acid molecules. The biosensor was a label-free and enzyme-free device with excellent reproducibility and stability that could identify single-base mismatched DNA without additional DNA amplification procedures, and the serum spiked experiments revealed the feasibility of the detection approach. Copyright © 2023 Elsevier B.V. All rights reserved.

Citation

Ruijiang Liu, Yanling Zhang, Min Liu, Yun Ni, Yao Yue, Shaobo Wu, Shasha Li. Electrochemical sensor based on Fe3O4/α-Fe2O3@Au magnetic nanocomposites for sensitive determination of the TP53 gene. Bioelectrochemistry (Amsterdam, Netherlands). 2023 Aug;152:108429