Advances in MXene-Based Electrochemical Sensors for Multiplexed Detection in Biofluids

Abstract

Detection of multiple analytes in biofluids is of significance for early disease diagnosis, effective treatment monitoring, and accurate prognostic assessment. Electrochemical sensors have emerged as a promising tool for the multiplexed detection of biofluids due to their low cost, high sensitivity, and rapid response. Two-dimensional transition metal carbon/nitride MXene, which has the advantages of a large specific surface area, good electrical conductivity, and abundant surface functional groups, has received increasing attention in the electrochemical sensing field. This paper systematically reviews the advances of MXene-based electrochemical sensors for multiplexed detection in biofluids, emphasizing the design of MXene-based electrode materials as well as the strategies for distinguishing multiple signals during simultaneous electrochemical analysis. In addition, this paper critically analyzes the existing challenges of MXene-based electrochemical sensors for multiplexed detection of biofluids and proposes future development directions for this field. The ultimate goal is to improve biofluid multiplexed detection technology for clinical medical applications.

Keywords: MXene; biofluids; electrochemical sensors; multiplexed; simultaneous.

Figure 1

Schematic of the different molecular structures of MXene and the constituent elements of MAX and MXene. Reproduced with permission from [36]. * (blue) refers to the elements in blue color below (Sc, Ti, V, etc.), and * (red) refers to the elements in red color below (Al, Si, P, etc.).

Figure 2

Schematic diagram for simultaneous electrochemical detection.

Figure 3

Fabrication process of flexible Ti₃C₂T_x/MWCNTs/Au electrode (a) and its working mechanism for Cu²⁺ and Zn²⁺ detection (b). Reproduced with permission from [65].

Figure 4

(a) Schematic of 2D MXene structure (top left), 3D MXene composite hydrogel (bottom right), and SEM image of the 3D MXene composite hydrogel (bottom left, scale bar = 10 μm). Reproduced with permission from [71]. (b) Schematic of the fabrication of a MXene-based microfluidic chip for the simultaneous and continuous analysis of urea, UA, and Cre in whole blood. Reproduced with permission from [74]. (c) Schematic diagram of oxygen-enriched GOx(LOx)/CNTs/Ti₃C₂T_x/PB/CFM electrode. Reproduced with permission from [76]. (d) Structural diagram of the HIS paper. Reproduced with permission from [77].

Figure 5

(a) Schematic of the preparation process of a 3D-MXting, antifouling nanocomposite. Reproduced with permission from [80]. (b) Schematic diagram of the assay procedure for simultaneous detection of microRNA-21 and microRNA-141. Reproduced with permission from [82].

Figure 6

(a) Mechanism to dope cationic ions via a carbon-PEG/PEDOT:PSS or PPy/Ti₃C₂T_x nanosheet. (b) Potentiometric sensing mechanism to detect Na⁺ in sweat interference. (c) Voltametric sensing mechanism to detect creatinine in sweat interference. Reproduced with permission from [84]. (d) Schematic of the preparation process of NS-TiO₂@MXene-HG and NS-TiO₂@MXene-HG/rGSPE. Reproduced with permission from [85].

Figure 7

(a) Schematic of the preparation procedure of Ti₃C₂T_x@AuNPs-ZnO@NC. Reproduced with permission from [88]. (b) Illustration of the synthesis of p-TC/hGO nanocomposite and its application in NFT and NLT simultaneous electrochemical detection. Reproduced with permission from [90].

Figure 8

Schematic of biofluids and corresponding targets detected by MXene-based, multiplexed electrochemical sensors.