The detection of current is critical within the context of industrial and power systems. Precise quantification of current is essential to ensure normal equipment functionality, enhance work productivity, and maintain the safety and integrity of power systems. This paper provides an overview of conventional current sensors and highlights the performance differences in current detection. The discussion encompasses current transformers, Rogowski coils, fiber optic current sensors, flux gates, and Hall current sensors. In light of the increasing complexity of current sensing requirements, conventional current sensors face challenges in meeting these demands. Thus, this study presents a comprehensive review of the development and fundamental principles of magnetoresistive sensors. This incorporates anisotropic magnetoresistive sensors, giant magnetoresistive sensors, and tunnel magnetoresistive sensors. Additionally, this paper examines the application of magnetoresistive sensors in current detection. Finally, the paper discusses the challenges and issues faced by magnetoresistive sensors in current detection, alongside the potential for future development trends.

Dopamine plays a crucial role in regulating various brain functions, making the development of highly sensitive detection methods and precise quantitative analysis techniques of great significance. However, realizing highly selective and sensitive detection of dopamine in complex biological environments remains a challenge. Here, we prepared three-dimensional (3D) crumpled Ti₃C₂T_x structures loaded with Pt nanoparticles (Pt/Na-Ti₃C₂T_x) by wet chemical reduction and ion intercalation. The synergistic coupling between Pt nanoparticles and MXene support facilitates efficient electron transfer between dopamine and the electrode surface, thereby improving the sensing performance of dopamine. Furthermore, this wrinkled structure not only enhances the specific surface area by inhibiting the stacking of layered Ti₃C₂T_x nanosheets, but also effectively prevents the agglomeration of nanoparticles. The experimental results showed that Pt/Na-Ti₃C₂T_x possessed a wide linear range (0.1–100 μM), a low detection limit (0.029 μM), and a high sensitivity (0.556 μA·μM⁻¹·cm⁻²). This work proposes an innovative strategy for achieving highly sensitive dopamine detection while advancing the utilization of MXene-based nanocomposites in electrochemical sensor development.