Plasmonic nanoparticles (NPs) adsorbing onto helical bacteria can lead to formation of NP helicoids with micron scale pitch. Associated chiroptical effects can be utilized as bioanalytical tool for bacterial detection and better understanding of the spectral behavior of helical self‐assembled structures with different scales. Here, we report that enantiomerically pure helices with micron scale of chirality can be assembled on Campylobacter jejuni, a helical bacterium known for severe stomach infections. These organisms have right‐handed helical shapes with a pitch of 1–2 microns and can serve as versatile templates for a variety of NPs. The bacteria itself shows no observable rotatory activity in the visible, red, and near‐IR ranges of electromagnetic spectrum. The bacterial dispersion acquires chiroptical activity at 500–750 nm upon plasmonic functionalization with Au NPs. Finite‐difference time‐domain simulations confirmed the attribution of the chiroptical activity to the helical assembly of gold nanoparticles. The position of the circular dichroism peaks observed for these chiral structures overlaps with those obtained before for Au NPs and their constructs with molecular and nanoscale chirality. This work provides an experimental and computational pathway to utilize chiroplasmonic particles assembled on bacteria for bioanalytical purposes.

中文翻译：

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等离子纳米粒子组件由螺旋细菌模板化并产生光学活性。

吸附在螺旋细菌上的等离子纳米颗粒（NPs）可以导致形成微米级间距的NP螺旋体。相关的按摩作用可以用作细菌检测的生物分析工具，并更好地理解不同尺度的螺旋自组装结构的光谱行为。在这里，我们报告可以在空肠弯曲菌上组装具有微米级手性的对映体纯螺旋，一种因严重胃部感染而闻名的螺旋细菌。这些生物具有右旋螺旋形状，间距为1-2微米，可以用作各种NP的通用模板。细菌本身在电磁光谱的可见，红色和近红外范围内均未观察到旋转活动。用金纳米颗粒进行等离激元功能化后，细菌的分散体在500–750 nm处获得了整脊活性。时域有限差分模拟证实了手性活动对金纳米颗粒螺旋组装的影响。这些手性结构观察到的圆二色性峰的位置与以前获得的Au NP及其具有分子和纳米级手性的结构重叠。