金–紫磷异质结的构建及协同增强声动力性能研究

Construction of Gold-Purple Phosphorus Heterojunction and Study on Synergistically Enhanced Sonodynamic Performance

摘要: 二维材料紫磷因其独特的层状结构、可调谐的带隙和本征压电性，在声动力治疗领域展现出良好的应用潜力。然而，单一紫磷纳米片在超声激发下产生的活性氧(ROS)量子产率较低，严重限制了其治疗效能的临床转化。为突破这一瓶颈，本研究采用原位还原策略，成功将金纳米颗粒(Au NPs)负载于紫磷纳米片表面，构建了Au@VP复合异质结体系。原子力显微镜显示金纳米颗粒均匀分布于紫磷表面，样品厚度和表面粗糙度较未修饰紫磷明显增加。Zeta电位与动态光散射(DLS)分析进一步证实了金纳米颗粒的成功负载，同时体系在生理环境中的分散稳定性得以有效维持。通过1,3-二苯基异苯并呋喃(DPBF)探针法对声动力性能进行定量评估，结果表明，金纳米颗粒的引入显著增强了紫磷在超声辐照下的活性氧生成能力，且增强效果随金纳米颗粒负载量的增加呈现正相关趋势。机制分析表明，金纳米颗粒作为空化核可降低空化阈值、增强局域声场，从而提高紫磷的超声激发效率，同时，复合后紫磷的带隙减小促进了电子空穴的产生。本研究为构建高效声动力治疗体系提供了新策略，在动脉粥样硬化等深部疾病治疗中具有潜在应用价值。

Abstract: Two-dimensional material violet phosphorus shows great potential for application in the field of sonodynamic therapy due to its unique layered structure, tunable bandgap, and intrinsic piezoelectric properties. However, the low quantum yield of reactive oxygen species (ROS) generated by single violet phosphorus nanosheets under ultrasound excitation severely limits the clinical translation of their therapeutic efficacy. To overcome this bottleneck, this study successfully loaded gold nanoparticles (Au NPs) onto the surface of violet phosphorus nanosheets using an in situ reduction strategy, thereby constructing an Au@VP composite heterojunction system. Atomic force microscopy revealed that the Au NPs were uniformly distributed on the violet phosphorus surface, with significant increases in sample thickness and surface roughness compared to unmodified violet phosphorus. Zeta potential and dynamic light scattering (DLS) analyses further confirmed the successful loading of Au NPs, while the dispersion stability of the system in physiological environments was effectively maintained. The sonodynamic performance was quantitatively evaluated using the 1,3-diphenylisobenzofuran (DPBF) probe method. The results demonstrated that the introduction of Au NPs significantly enhanced the ROS generation capability of violet phosphorus under ultrasound irradiation, with the enhancement effect showing a positive correlation with increasing Au NP loading. Mechanistic analysis indicates that the Au NPs act as cavitation nuclei, reducing the cavitation threshold and enhancing the local acoustic field, thereby improving the ultrasound excitation efficiency of violet phosphorus. Additionally, the reduction in the bandgap of violet phosphorus after composite formation promotes the generation of electron-hole pairs. This study provides a new strategy for constructing highly efficient sonodynamic therapy systems and holds potential application value in the treatment of deep-seated diseases such as atherosclerosis.