Application Prospects of MXenes Materials Modifications for Sensors

Abstract

The first two-dimensional (2D) substance sparked a boom in research since this type of material showed potential promise for applications in field sensors. A class of 2D transition metal nitrides, carbides, and carbonitrides are referred to as MXenes. Following the 2011 synthesis of Ti₃C₂ from Ti₃AlC₂, much research has been published. Since these materials have several advantages over conventional 2D materials, they have been extensively researched, synthesized, and studied by many research organizations. To give readers a general understanding of these well-liked materials, this review examines the structures of MXenes, discusses various synthesis procedures, and analyzes physicochemistry properties, particularly optical, electronic, structural, and mechanical properties. The focus of this review is the analysis of modern advancements in the development of MXene-based sensors, including electrochemical sensors, gas sensors, biosensors, optical sensors, and wearable sensors. Finally, the opportunities and challenges for further study on the creation of MXenes-based sensors are discussed.

Keywords: MXenes nanomaterial; biosensor; electrochemistry sensor; gas sensor; optical sensor; wearable sensors.

Figure 2

(a) Steps in the synthesis of MXene nanomaterials by top-down method from precursor to etching; bottom-up techniques are shown schematically in (b) chemical vapor deposition of Mo and C to generate a thin film of Mo₂C in a gas chamber and (c) the synthesis of MoN nanosheets using a salt template. Reproduced with permission from references [18,26,27].

Figure 1

An overview of the applications of MXenes in the sensor, including gas sensors, electrochemical sensors, biosensors, optical sensors, wearable sensors, and synthesis & properties.

Figure 3

(a) After the production of surface terminations (yellow atoms) and the A-group layers were etched selectively (red atoms), three different mono-M MAX phases—M₂AX, M₃AX₂, and M₄AX₃—MXenes were produced. M, A, X, and T components that could be present in the MAX and MXene phases; (b) the synthesized M₂X, M₃X₂, and M₄X₃ MXenes, which are double transition metals (DTM). The transition metals M′ and M′′ are represented by the green and purple elements, correspondingly. Both the in-plane divacancy order (M′_4/3X) and the in-plane order (M′_4/3M′′_2/3X). The order that is out of a plane (M′₂M′′X₂ and M′₂M′′₂X₃). M′ and M′′ transition metals are dispersed throughout the disordered MXenes in solid solutions. Additionally, solid solution (Mo_0.8V_0.2)₅C₄T_x was prepared successfully; however, it has not been shown for simplicity’s sake. Reproduced with permission from reference [29].

Figure 4

(a) Illustration of a schematic of the nanohybrids of Ti₃C₂T_x and WSe₂; (b) a diagram depiction of inkjet-printed gas sensors used in a wireless monitoring system for detecting volatile organic compounds; (c) distributions of the zeta potential for the CTA⁺-WSe₂ dispersions, WSe₂, Ti₃C₂Tx; (d) diagrammatic illustration of the Ti₃C₂T_x films, its atomic structure. Reproduced with permission from references [49,53].

Figure 5

(a) The virtual sensor array of MXene 2D material for the ethanol detection in the presence of various concentrations of methanol and water; (b) simulation of 2D layered Transition-metal carbide and calculations for NH₃ gas detection; (c) Ti₃C₂T_x/WSe₂ energy-band graph in air and ethanol, illustrating the change in the depletion region caused by the interaction of adsorbed oxygen species and ethanol molecules. Reproduced with permission from references [49,54,55].

Figure 6

(a) An example of a diagram showing how the electrochemical glucose sensor functions; (b) a graphitic pencil electrode with perylene diimide-MXene integration for the electrochemical sensing of dopamine and amperometric current-time response curves for the gradual addition of various concentrations of dopamine solution. Reproduced with permission from references [75,76].

Figure 7

(a) Examples of the production of a 1D/2D MnMoO₄/MXene nanomaterial sensing for the simultaneous detection of catechol (CC) and hydroquinone (HQ), as well as EIS and DPV responses to different concentrations of HQ and CC in MXene nanocomposite materials; (b) based on the MXene-CNHs-CD-MOF electrode, an electrochemical sensor for the detection of carbendazim was developed. Reproduced with permission from references [77,79].

Figure 8

Diagrammatic representation of the operation of a ratiometric antifouling electrochemical biosensor is indicated in (a), along with (b) SEM pictures of a composite made of MXene and Au at various magnifications and (c) a sensor interface that reacts to PSA’s DPV signal without a standard solution. Reproduced with permission from reference [86].

Figure 9

(a) A diagram showing how T-RMFs nanobelts are made and coated; (b) the RMFs’ temperature growth profiles under NIR light (0.33, 0.50, 1.0 W), as well as the T-RMFs’ and RMFs’ temperatures over five on/off cycles; (c) thermal pictures taken with NIR light (0.33 W) of the comparison group, T-RMFs, and RMFs. Reproduced with permission from reference [87].

Figure 10

(a) 2D MXene Ti₃C₂T_x improves the sensitivity of optical fiber nanosensors, including RI and SPR sensors; (b) differences in the standardized intensity of light to wavelength for the traditional fiber optic surface plasmon resonance (SPR) nanosensor of Au film and the optical sensor with the MXene layer; (c) The graphs of an optical fiber RI detector before and after the MXene Ns modification. Reproduced with permission from reference [93].

Figure 11

(a) The simple photoreduction procedure used to incorporate gold nanoparticles into MXene to increase its SERS activity to detect antipsychotic drugs; (b) a sketch structure of MXene, which consists of two semi-infinite media with the refractive indices n₁ (the bottom material, SiO₂) and n₂ (the top material), and Ti₃C₂T_x sandwiched between two thin layers; (c) numerical findings for the distributions of Hx field and electric field on the yz planes, respectively, taking into account several materials for the top dielectric: n₂ = 1.25 (top) and n₂ = 1.55 (bottom). Reproduced with permission from references [88,96].

Figure 12

(a) Sandwiching a thin sheet of a biodegradable polylactic acid (PLA) and an interdigitated electrode-coated PLA between two porous MXene-impregnated tissue papers to anticipate the potential health condition of patients and serve as a tactile input mapping electronic skin; (b) images of the stretchable transient pressure sensor for wearables; (c) the suggested, designed, characterized, and verified wearable device for MXene-based, adaptable, and integrated physiological biosignals monitoring for continuous, real-time. Reproduced with permission from references [101,102].