Recent Advances in MXene Nanocomposite-Based Biosensors

Abstract

The development of advanced biosensors with high sensitivity and selectivity is one of the most demanded concerns in the field of biosensors. To meet this requirement, up until now, numerous nanomaterials have been introduced to develop biosensors for achieving high sensitivity and selectivity. Among the latest nanomaterials attracting attention, MXene is one of the best materials for the development of biosensors because of its various superior properties. MXenes are two-dimensional inorganic compounds with few atomic layers that possess excellent characteristics including high conductivity and superior fluorescent, optical, and plasmonic properties. In this review, advanced biosensors developed on the basis of the MXene nanocomposite are discussed with the selective overview of recently reported studies. For this, introduction of the MXene including the definition, synthesis methods, and its properties are discussed. Next, MXene-based electrochemical biosensors and MXene-based fluorescent/optical biosensors are provided, which are developed on the basis of the exceptional properties of the MXene nanocomposite. This review will suggest the direction for use of the Mxene nanocomposite to develop advanced biosensors with high sensitivity and selectivity.

Keywords: MXenes; biosensors; electrochemical biosensor; fluorescent/optical biosensor; high sensitivity/selectivity; nanomaterials.

Figure 2

Definition and characteristics of MXenes. (a) Schematic diagram of the synthesis process from the MAX phase to the MXene nanosheets, and SEM images of the MAX phase (Ti₃AlC₂) before and after hydrofluoric acid (HF) treatment (reprinted with permission from [37]; copyright (2012) American Chemical Society). (b) Crystal structure images of the MAX phase of Ti₃AlC₂, and the low-magnification and atomic resolution high-angle annular dark field (HAADF)-scanning transmission electron microscopy (STEM) images of Ti₃C₂T_x (reprinted with permission from [39]; copyright (2016) American Chemical Society). (c) Schematic image of the MXene/Au nanostructure (NS) SERS substrate fabrication process, XRD pattern, and TEM image of synthesized MXene (Ti₃C₂T_x), and the Raman spectra of R6G on the MXene/Au NSs SERS substrate with different concentration ranges of R6G (reprinted with permission from [45]; copyright (2019) The Royal Society of Chemistry). (d) Schematic image of the MXene-derived quantum dot (MQD) synthesis process using different solvents such as the dimethylformamide (DMF), DMSO, and ethanol (f-MQDs, s-MQDs, and e-MQDs, respectively), and the XRD pattern and FTIR spectra of the e-MQDs (black), f-MQDs (blue), and s-MQDs (red) (reprinted with permission from [41]; copyright (2018) John Wiley and Sons, Inc.).

Figure 1

Recent advances in the development of advanced biosensors based on MXene nanocomposites.

Figure 3

MXene-based electrochemical biosensors. (a) Construction of the MXene (Ti₃C₂T_x) and graphene hybrid film (MG hybrid film): the SEM and cross-sectional images of the MG hybrid film, and the calibration plot of current versus different concentrations of the glucose obtained by using the MG hybrid film-based glucose biosensor (reprinted with permission from [51]; copyright (2019) American Chemical Society). (b) Schematic image of the sensing probe electrode in the wearable biosensing system based on the MXene/Prussian blue composite, and the optical image of the wearable electrochemical multifunctional biosensing patch system connected to the portable device and human body (reprinted with permission from [52]; copyright (2019) John Wiley and Sons, Inc.). (c) Schematic diagram of the label-free electrochemical gliotoxin biosensor based on the nanocomplexes composed of the tetrahedral DNA nanostructure (TDN), MXene nanosheet, and horseradish peroxidase (HRP); its sensing mechanism; and amperometric response curves, and the analyzed logarithmic plot for the detection of gliotoxin (reprinted with permission from [53]; copyright (2019) Elsevier publishing).

Figure 4

MXene-based fluorescent/optical biosensors. (a) Schematic image of the fluorescence resonance energy transfer (FRET)-based biosensing system based on the MXene nanosheets combined with Cy3-labeled CD63 aptamer and fluorescence signal of Cy3-labeled CD63 aptamer with different exosome concentrations and its linear calibration curve (reprinted with permission from [54]; copyright (2018) American Chemical Society). (b) Schematic images of the synthesis process of the MQDs and its Fe³⁺ detection mechanism, the fluorescence signal of the MQDs with or without 100 μM Fe³⁺, and the fluorescence signal of MQDs with different concentrations of Fe³⁺ (reprinted with permission from [55]; copyright (2020) The Royal Society of Chemistry). (c) Schematic image of the MXene nanosheet and the Ni, Fe layered double hydroxide (NiFe-LDH) (MXene/NiFe-LDH)-based colorimetric biosensor for glutathione (GSH) detection and absorbance spectrum of different configurations of MXene/NiFe-LDH in tetramethylbenzidine (TMB) and H₂O₂ with change of color and its linear calibration curve (reprinted with permission from [56]; copyright (2019) American Chemical Society).