Development and performance evaluation of a magnetic self-assembled electrochemical biosensor based on α-Fe2O3/Fe3O4 heterogeneous nanorods for supersensitive detection of KRAS

The Kirsten Rat Sarcoma Viral Oncogene (KRAS) represents one of the most frequently mutated oncogenes in a variety of malignant tumors, including non-small cell lung cancer (NSCLC), colorectal cancer (CRC), and pancreatic ductal adenocarcinoma (PDAC). Therefore, it is regarded as a pivotal tumor marker, and the detection of it holds immense significance in the realm of tumor prevention, diagnosis, and disease monitoring. In this project, an α-Fe 2 O 3 /Fe 3 O 4 @Au-DNA/BSA probe was progressively constructed to capture KRAS, and the binding probe was immobilized onto the surface of magnetic glass carbon electrodes (MGCE) through magnetic self-assembly for detection purposes. The fabrication process was validated by changes observed in cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) data. Differential pulse voltammetry (DPV) was employed to optimize crucial experimental conditions and analyze biosensor performance. This condition optimization resulted in enhanced sensitivity of the biosensor, leading to improved linearity of data obtained. The limit of detection (LOD) achieved was 1.93 pM, with a limit of quantification (LOQ) at 5.84 pM, and a linear range ranging from 10 pM to 1 μM. Additionally, the stability (the current maintaining stability during the initial eight days), reproducibility (RSD = 2.47 %), selectivity, and real sample analysis (recovery rates ranging from 95.26 % to 109.80 %, RSD ≤ 1.22 %) were found to be favorable. These findings suggest promising prospects for practical applications of this biosensor.