The emergence of drug-resistant bacteria is becoming the focus of global public health. Early-stage pathogen bioimaging will offer a unique perspective to obtain infection information in patients. A photoacoustic (PA) contrast agent based on functional peptide modified gold nanoparticles (AuNPs@P1) is developed. These nanoparticles can be specifically tailored surface peptides by bacterial overexpressed enzyme inducing in situ aggregation of the gold nanoparticles. In the meantime, the close aggregation based on the hydrogen bonding, π-π stacking, and hydrophobic interaction of the peptide residues on the surface of gold nanoparticles exhibits a typical redshifted and broadened plasmon band. In addition, this active targeting and following in situ stimuli-induced aggregation contribute to increased nanoparticle accumulation in the infected site. Finally, the dynamic aggregation of AuNPs@P1 results in dramatically enhanced photoacoustic signals for bioimaging bacterial infection in vivo with high sensitivity and specificity. It is envisioned that this PA contrast agent may provide a new approach for early detection of bacterial infection in vivo.

中文翻译：

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用于细菌感染生物成像的具有增强的光声信号的细菌指导的AuNPs原位聚集。

耐药细菌的出现正成为全球公共卫生的重点。早期病原体生物成像将为获得患者的感染信息提供独特的视角。开发了一种基于功能性肽修饰的金纳米粒子（AuNPs @ P1）的光声（PA）造影剂。这些纳米颗粒可以通过细菌过表达的酶诱导金纳米颗粒的原位聚集而专门定制表面肽。同时，基于氢键，π-π堆积和金纳米颗粒表面上的肽残基的疏水相互作用的紧密聚集表现出典型的红移和加宽的等离激元带。另外，这种主动靶向和在原位刺激诱导的聚集之后有助于增加纳米颗粒在受感染部位的积累。最后，AuNPs @ P1的动态聚集可显着增强光声信号，从而以高灵敏度和特异性在体内进行生物成像细菌感染。可以预见，这种PA造影剂可以为体内细菌感染的早期检测提供一种新方法。