Fabrication of Graphene/Molybdenum Disulfide Composites and Their Usage as Actuators for Electrochemical Sensors and Biosensors

Abstract

From the rediscovery of graphene in 2004, the interest in layered graphene analogs has been exponentially growing through various fields of science. Due to their unique properties, novel two-dimensional family of materials and especially transition metal dichalcogenides are promising for development of advanced materials of unprecedented functions. Progress in 2D materials synthesis paved the way for the studies on their hybridization with other materials to create functional composites, whose electronic, physical or chemical properties can be engineered for special applications. In this review we focused on recent progress in graphene-based and MoS₂ hybrid nanostructures. We summarized and discussed various fabrication approaches and mentioned different 2D and 3D structures of composite materials with emphasis on their advances for electroanalytical chemistry. The major part of this review provides a comprehensive overview of the application of graphene-based materials and MoS₂ composites in the fields of electrochemical sensors and biosensors.

Keywords: 2D materials; bioanalysis; biomarker; carbon; electrode.

Figure 1

(A) TEM images and (B) HRTEM images of vertically aligned exfolliated graphite and MoS₂ composite. From Wang et al. [22]. (C) Schematic illustration of the formation of the graphene/MoS₂/amorphous carbon composite. From Teng et al. [23]. (D) FE-SEM and (E) TEM images of the MoS₂ and carbon nanofiber composite. The insert shows the TEM image of a single MoS₂ and carbon nanofiber nanostructure. From Li et al. [29].

Figure 2

(A) Schematic representation showing synthesis of S-doped reduced graphene oxide (rGO)/MoS₂ composite. From Wang et al. [32]. (B) Low-magnification and (C) high-magnification TEM images of rGO/MoS₂ composite fabricated by one-pot microwave synthesis. From Li et al. [37]. (D) Schematic diagram of the chemical bath deposition of MoS₂ on graphene as the anode and carbon rod as the cathode. From Wan et al. [41]. (E) Schematic of the two-zone chemical vapor deposition (CVD) furnace utilized for the synthesis of vertical MoS₂ on graphene. From Gnanasekar et al. [44].

Figure 3

(A) Cyclic voltammetry CV curves of the glassy carbon electrode (GCE), GCE modified with rGO, MoS₂ and rGO/MoS₂ in 0.1 M PBS (pH = 7.0) with 500 μM nitrite. (B) CV curves of the GCE modified with rGO/MoS₂ in 0.1 M PBS (pH = 7.0) under different concentrations of nitrite: 100, 300, 500, 700, and 1000 μM (scan rate: 50 mV∙s⁻¹). Both from Hu et al. [55]. (C) CV curves of rGO (black) and rGO/MoS₂ paper electrodes in 0.1 M PBS (pH 7.0) with (blue) and without (red) 2.0 mM folic acid (FA). Scan rate: 50 mV∙s⁻¹. Inset: Structure of FA. (D) The CVs of the same concentrations of ascorbic acid (AA, blue line), uric acid (UA, green line) and FA (black line) and 1.0 mM AA, 0.5 mM UA and 0.5 mM FA containing solution (red line) at the rGO/MoS₂ composite paper electrode in pH 7.0 PBS. Scan rate: 50 mV∙ s⁻¹. Both from Kiransan et al. [59].

Figure 4

(A) Schematic of electrochemical biosensors composed of myoglobin (Mb) and of GO/MoS₂ with electrochemical enhancement for H₂O₂ detection. From Yoon et al. [60]. (B) Schematic representation of construction and the detection principle of screen-printed carbon electrode modified with graphene quantum dots, MoS₂ and laccase as a caffeic acid biosensor. From Vasilescu et al. [69]. (C) Schematic representation of the reduced graphene oxide/molybdenum disulfide/polyaniline nanocomposite-based electrochemical aptasensor for detection of aflatoxin B₁ fabrication. (D) Differential pulse voltammetry (DPV) responses of the aptasensor after 20 min incubation with 0.0100, 0.0156, 0.0313, 0.0625, 0.125, and 1.00 fg∙mL⁻¹ AFB₁. Both from Geleta et al. [72]. (E) Schematic illustration of magnetic beads assisted bi-nanozyme signal amplification for detection of circulating tumor cells. (F) DPV responses to MCF-7/aptamer/Fe₃O₄NPs/rGO/MoS₂/GCE-fabricated cytosensor after capturing different concentrations of MCF-7 cells from (a) to (h): 0, 15, 20, 25, 30, 35, 40 and 45 cells∙mL⁻¹ in 0.01M PBS (pH=5.0) with 0.1mM of H₂O₂ and 0.2mM of TMB. Both from Tian et al. [74].