A type of magnetic electrochemical nano-biosensors for sensitive detection of heterogeneous nuclear ribonucleoprotein A1.

INTRODUCTION: The detection of tumor markers has become an important non-invasive detection method for early detection, diagnosis, and prognosis and treatment of tumors. METHODS: In this work, we designed and developed a novel type of electrochemical nano-biosensors characterized by magnetically driven self-assembly based on Fe3O4/α-Fe2O3 (ferriferrous oxide/α-iron trioxide, FOαIT) magnetic heterogeneous nanorods fabricated with CTAB as a restricted growth agent for sensitive detection of heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1). Firstly, FOαIT@Au magnetic nanocomposites (MNCs) were prepared via the hydrothermal and calcination-reduction process with Au nanoparticles (AuNPs) modified on the surface. With the help of Au-S bonding, ssDNA/BC15 was immobilized to form FOαIT@Au/ssDNA/BC15. To avoid the effect of nonspecific sites to the detection, BSA was employed to block them and form FOαIT@Au/ssDNA/BC15/BSA nano-biosensors. Utilizing the stronger linkage force of hnRNP A1 with BC15 than that of FOαIT@Au/ssDNA, the sensitive and accurate detection of hnRNP A1 was realized. RESULTS AND DISCUSSION: The nano-biosensors revealed a decent linear relationship with a lower LOD of 0.103 pg/mL, higher sensitivity, excellent selectivity, satisfactory repeatability (RSD ≤1.55%), dependable long-term stability, and the accurate detection of spiked samples, revealing the promising application prospect in the clinical examination.