Magnetic Nanowires for Nanobarcoding and Beyond

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

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.

Study on Sgc8 Aptamer-mediated Nucleic Acid Nanomaterial-doxorubicin Complex for Tumor Targeted Therapy

Chemotherapy is one of the most important treatments for malignant cancers, but most chemotherapeutic drugs are poorly targeted, highly toxic and expensive, resulting in unsatisfactory treatment results for cancer patients. Therefore, intelligent drug delivery platforms are needed to be explored urgently to enhance drug treatment and reduce toxicity on normal cells. Nucleic acid nanomaterials are a class of nanomaterials developed on the basis of the "base complementary pairing principle", which have the advantages of good programmability, high stability, good biocompatibility, and strong targeting. Herein, we present a simple Sgc8 aptamer-modified nucleic acid nanomaterial (Sgc8NM) for the targeted delivery of Doxorubicin (Dox), a widely used chemotherapy drug in clinic. Studies have shown the Sgc8NM-Dox performed a precise treatment effect on target cells and low toxicity on non-target cells, providing a new strategy for the potential application of nanocomposite drugs in targeted cancer delivery.