2D/0D Heterojunction Interface with Photovoltaic Enhancement and Stabilization for Label‐Free Exosome Biosensor

Abstract The selection and design of interface materials as the key to interface engineering is crucial for the excellent performance of optoelectronic devices, enabling multi‐functional integration at interfaces. MXene has been extensively employed in optoelectronic devices as an interface material. The primary drawback in interfacial applications, however, is MXene's vulnerability to oxidation in hot, humid environments, which severely reduces photovoltaic performance. Based on hetero‐interface engineering, this work offers a novel 2D‐semiconductor/0D‐plasma heterojunction MXene‐TA‐Au‐PEG (MTAP) as a high‐performance and multifunctional photovoltaic interfacial material. MTAP not only effectively protects MXene against stacking and spontaneous oxidation, but also exhibits excellent optoelectronic properties and interfacial antifouling capability. Moreover, MTAP is employed to enhance SPR spectroscopy, allowing for the direct, real‐time detection of tumor cell exosomes with LODs as low as 0.28 particles mL −1 . MTAP effectively addresses the conventional “three S” requirements for sensors in terms of sensitivity, specificity, and stability by integrating photoelectric enhancement, interfacial antifouling, and oxidative stabilization characteristics. Finally, the results of serum sample analysis showed the sensor has some potential application value in clinical diagnosis. This study offers novel perspectives on the fabrication of 2D/0D heterojunctions using semiconductor and plasma materials, with the aim of developing improved sensing chips.