Ni/Co Bimetallic Metal–Organic Frameworks on Nitrogen-Doped Graphene Oxide Nanoribbons for Electrochemical Sensing of Doxorubicin

Abstract

Metal–organic frameworks (MOFs) have previously been researched for electrochemical sensor development. MOFs are commonly stated to have low conductivity, and improving their conductivity remains a significant challenge. We described the preparation of an electrochemical sensor depending on the in situ growth of NiCo-BTC bimetallic MOFs, as model bimetallic MOFs, on a glassy carbon electrode modified with conductive nitrogen-doped graphene oxide nanoribbons (NiCo-BTC MOFs/N-GONRs/GCE). The proposed NiCo-BTC MOFs/N-GONRs/GCE was characterized using X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), field emission scanning electron microscopy (FESEM), Fourier transform infrared (FT-IR), X-ray diffraction (XRD), electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and Raman spectroscopy. The square-wave voltammetry response of NiCo-BTC MOFs/N-GONRs/GCE to doxorubicin (DOX) is significantly greater than that of NiCo-BTC MOFs/GCE due to the synergic effect between N-GONRs and NiCo-BTC MOFs. The NiCo-BTC MOFs on the modified electrode act as active materials for sensing DOX. The calibration curve for DOX at the NiCo-BTC MOFs/N-GONRs/GCE showed two linear dynamic ranges, 0.01–1.0 and 1.0–80 μmol L–1, with a detection limit of 0.006 μmol L–1 (or 6 nmol L–1), which is less than the DOX concentration in human plasma samples (i.e., 77.2 ± 10.5 nmol L–1). Here, a modified electrode was designed using the large surface area of bimetallic MOFs and conductivity of N-GONRs for the electrochemical sensing of DOX. The current procedure offers a viable solution to the poor conductivity of bimetallic MOFs. Finally, the observed result shows that the proposed NiCo-BTC MOFs/GCE is promising for determining DOX in real samples of human urine and serum.