Label-free electrochemical bioplatform based on Au-modified magnetic Fe3O4/α-Fe2O3 hetero-nanorods for sensitive quantification of ovarian cancer tumor marker

Abstract

Due to challenges in the ultrasensitive detection of human epididymis protein 4 (HE4), a vital tumor marker for the early diagnosis of ovarian cancer (OC), it is necessary to establish efficient methods for HE4 determination. Recently, electrochemical bioplatforms combined with nanomaterials have shown outstanding performance in the analysis of biological molecules. The surface modification of conductive materials is essential for signal amplification and detection sensitivity. Herein, we developed a novel label-free HE4 electrochemical bioplatform by introducing magnetic Fe3O4/α-Fe2O3 hetero-nanorods (Fe3O4/α-Fe2O3 NRs) as a substrate for signal amplification and DNA aptamer (Apt) probe immobilization in combination with magnetic self-assembly and magnetic separation. Differential pulse voltammetry (DPV) results verified that the platform had excellent specificity for HE4 under optimized conditions and was positively linearly correlated with the logarithm of HE4 concentration (R2 = 0.996) with a linear range of 0.1 pg mL−1 to 1 ng mL−1 and detection limit (LOD) of 27.5 fg mL−1. Moreover, the bioplatform demonstrated promising results for the detection of HE4 in spiked serum samples.