A new class of cationic gold nanoparticles (NPs) has been synthesised bearing benzyl moieties featuring –NO2 and –OMe groups to investigate the regioisomeric control of aromatic NP–protein recognition. In general, NPs bearing electron-withdrawing groups demonstrated higher binding affinities towards green fluorescent protein (GFP) than NPs bearing electron-donating groups. Significantly, a ∼7.5- and ∼4.3-fold increase in binding with GFP was observed for –NO2 groups in meta-position and para-position, respectively, while ortho-substitution showed binding similar to the unsubstituted ring. These findings demonstrated that the NP–protein interaction can be controlled by tuning the spatial orientation and the relative electronic properties of the aromatic substituents. This improved biomolecular recognition provides opportunities for enhanced biosensing and functional protein delivery to the cells.

中文翻译：

---

探索蛋白质-纳米粒子界面：芳香取代模式对亲和力的作用

已经合成了一类新的阳离子金纳米粒子 (NPs)，其带有具有 -NO2 和 -OMe 基团的苄基部分，以研究芳香 NP 蛋白质识别的区域异构控制。一般来说，带有吸电子基团的 NPs 比带有供电子基团的 NPs 对绿色荧光蛋白 (GFP) 表现出更高的结合亲和力。值得注意的是，观察到间位和对位的 -NO2 基团与 GFP 的结合分别增加了约 7.5 倍和约 4.3 倍，而邻位取代显示出与未取代环相似的结合。这些发现表明，NP-蛋白质相互作用可以通过调节芳香取代基的空间取向和相对电子特性来控制。