Silver nanoparticles (AgNPs) exhibit excellent anti-microbial and bactericidal properties. Due to bacterial abhorrence for AgNPs, it is difficult to develop a label-free, sensitive and low-cost bacteria sensor using them. In the present article, we report that an ultrathin and uniform Langmuir–Schaefer (LS) film of AgNPs can be employed for bacteria sensing effectively as compared to that of non-uniform and randomly distributed AgNPs in spin coated film. The uniformly distributed AgNPs in the LS film offer a relatively larger contact surface for bacteria as compared to that of spin coated film. Due to higher contact surface, adsorption of the bacteria on LS film is strongly preferable as compared to that of spin coated film leading to an enhanced sensing performance of the LS film than that of spin coated film. Soil bacteria was grown by the standard protocol and were utilized as model system for bacteria sensing application. The soil bacteria sensing was done by monitoring the piezoresponse and dissipation parameters using a quartz crystal microbalance, simultaneously. Our study indicates that the LS film of AgNPs not only facilitates the adsorption of the soil bacteria but also kills them.

银纳米颗粒（AgNPs）具有出色的抗菌和杀菌性能。由于AgNPs的细菌厌恶，很难开发出使用它们的无标签，灵敏且低成本的细菌传感器。在本文中，我们报道，与旋涂膜中非均匀且随机分布的AgNP相比，超薄且均匀的Langmuir-Schaefer（LS）AgNPs膜可有效地用于细菌感测。与旋涂膜相比，LS膜中均匀分布的AgNPs为细菌提供了相对较大的接触表面。由于更高的接触表面，与旋涂膜相比细菌在LS膜上的吸附是强烈优选的，这导致LS膜的感测性能比旋涂膜的增强。土壤细菌按标准方案生长，并用作细菌感测应用的模型系统。通过同时使用石英晶体微量天平监测压电响应和耗散参数来完成土壤细菌感测。我们的研究表明，AgNPs的LS膜不仅有助于土壤细菌的吸附，而且可以杀死它们。