Multimodal imaging that aims to advance imaging by strategically combining existing technologies with uniquely designed probes has attracted great interest in recent years. In this work, Gd³⁺-functionalized gold nanoclusters were prepared with a straightforward and scalable approach by using proteins as templates. The impact of the synthesis approach on the conjugation efficiency of Gd chelators to proteins, as well as the fluorescence quantum yield of gold nanoclusters was carefully studied. The effect of protein size on the relaxivities of the probes was also investigated. By using the optimal conditions, dual function probes with intense red fluorescence emission and longitudinal relaxivity as high as 9.7 mM⁻¹ s⁻¹ could be obtained. The probes were applied for cell staining and in vivo contrast-enhanced magnetic resonance imaging (MRI). The MR images showed that the dual function probes circulated freely in the blood pool without undesirable accumulation in the liver and spleen. Meanwhile, the material could be removed from the body through renal clearance, making it attractive for practical multimodal imaging.

中文翻译：

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Gd ³⁺ -功能化的金纳米簇，用于荧光-磁共振双峰成像

近年来，旨在通过将现有技术与独特设计的探头进行战略性结合来推进成像的多峰成像技术引起了人们的极大兴趣。在这项工作中，通过使用蛋白质作为模板，以一种直接且可扩展的方法制备了Gd ³⁺功能化的金纳米簇。仔细研究了合成方法对Gd螯合剂与蛋白质的结合效率以及金纳米团簇的荧光量子产率的影响。还研究了蛋白质大小对探针弛豫性的影响。通过使用最佳条件，具有强烈红色荧光发射和纵向弛豫度高达9.7 mM ^-1 s ^-1的双功能探针可以获得。该探针用于细胞染色和体内对比增强磁共振成像（MRI）。MR图像显示双功能探针在血池中自由循环，而在肝脏和脾脏中没有不希望的积累。同时，可以通过肾脏清除从体内清除该物质，使其对实用的多峰成像具有吸引力。