A type of magnetically induced self-assembled electrochemical aptamer nanobiosensor for ultrasensitive detection of hypoxia-inducible factor 1α protein
Hypoxia-inducible factor 1α (HIF-1α) protein has been identified as an aggressive malignant phenotype marker for numerous tumors; therefore, the detection of HIF-1α has become increasingly significant. In this work, we developed a type of magnetically induced self-assembled electrochemical aptamer nanobiosensor for detecting HIF-1α protein. This nanobiosensor utilized the magnetism of hydrothermal-calcination-synthesized α-ferric oxide/ferriferrous oxide (α-Fe 2 O 3 /Fe 3 O 4 , αFO/FFO) magnetic heterogeneous nanorods (MHNRs) to realize magnetically induced self-assembly; further, gold nanoparticles (AuNPs) were used to reinforce the electron transfer capacity and realize secure immobilization of the aptamer via Au–S bonds. Finally, we adopted cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV) for the electrochemical characterization, condition optimization, and performance analysis of the nanobiosensor, respectively. The nanobiosensor revealed a favorable linear relation in the range of 0.1–1,000 ng/mL with a variance R 2 of 0.995 and limit of detection of 0.112 ng/mL, excellent sensitivity, faithful reproducibility with a relative standard deviation (RSD) of 2.28%, reliable 13-d stability with an RSD of 1.71%, and accredited detection capacity for real samples with recoveries of 97.71%–107.47% and RSDs ≤ 3.47%. In this study, we developed a magnetically induced self-assembled electrochemical aptamer nanobiosensor for ultrasensitive detection of HIF-1α protein. The nanosensor delivers outstanding analytical performance with a facile assay strategy suitable for point-of-care testing, suggesting its promising prospects for clinical tests.