Hierarchical nickel hydroxide nanosheets grown on hollow nitrogen doped carbon nanoboxes as a high-performance surface substrate for alpha-fetoprotein cancer biomarkers electrochemical aptasensing.

Abstract During recent decades, we have witnessed a great improvement in the performance of aptamer-based sensors, specifically when aptamers are combined with new nanomaterials; as a platform for biosensors. The design of hollow carbon-based materials has also received a lot of attention due to its excellent properties in various applications. Herein, we aim at designing hierarchical porous Ni(OH)2 nanosheets on hollow N-doped carbon nanoboxes Ni(OH)2@N-C n-box). In this sense, we obtained the hollow N-C n-box skeletons from the Fe2O3 nanocubes template. The development of label-free electrochemical aptasensor was carried out using the covalently immobilizing NH2-functionalized aptamer on Ni(OH)2@N-C n-box as an efficient substrate. The Ni(OH)2@N-C n-box was characterized using scanning fourier transform infrared spectroscopy (FTIR), X-ray Diffraction (XRD), Brunauer, Emmett and Teller (BET), transmission electron microscopes (TEM) and electron microscopy (FESEM). The electrochemical evaluations clarified the fact that a linear relationship exists between the alpha-fetoprotein (AFP) contents and the charge transfer resistance (Rct) (from 1 fg mL−1 to 100 ng mL−1) with a low detection limit of 0.3 fg mL−1. Moreover, regarding the aptasensor, the superior detection recoveries were experienced in real biological samples, illustrating its great detection performance and practical feasibility. Considering the aptasensor application, these studies showed that Ni(OH)2@N-C n-box possesses different enhanced electrochemical features, making it appropriate as an electrode material for aptasensor application.