Pathogenic bacteria represent a severe threat to global public health, particularly with the growing rate of antibiotic resistance, and, therefore, indicate a critical need for developing efficient sensing platforms. Liposome-based sensors are collocating interest due to their intrinsic fusogenic ability to fuse with the outer membrane of bacteria. However, the lack of a conducting property limits their applicability for developing biosensing platforms. In this study, we report conjugation of liposomes with reduced graphene oxide (rGO) for fabricating a rapid and sensitive biosensor for electrochemical detection of Escherichia coli (E. coli). The large surface area of rGO facilitated binding of liposomes with their surface, and the intrinsic electrical and biocompatible properties assisted electrochemical sensing of bacteria. The electrochemical response of the liposome and the rGO-liposome coated electrode shows nonconducting and conducting characteristics, respectively. A significant change in the peak current of differential pulse voltammetry with the gradual variation of bacterial density in the electrolyte was observed for the glassy carbon electrode rGO-liposome (GCE-L-rGO) surface only. The detection sensitivity of GCE-L-rGO sensors was ∼26 μA/106 cells per ml of electrolyte for varying cell densities from 3 × 103 to 3 × 104 cells/ml. The proposed sensing technique can serve as an alternative to conventional methodologies for rapid and in situ detection of bacterial load in different samples, laying the foundation for new applications in clinical diagnostics.

中文翻译：

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脂质体功能化还原氧化石墨烯用于细菌的快速电化学传感。

致病菌对全球公共卫生构成严重威胁，特别是随着抗生素耐药性的增加，因此表明迫切需要开发高效的传感平台。基于脂质体的传感器因其与细菌外膜融合的内在融合能力而受到关注。然而，缺乏导电性限制了它们在开发生物传感平台方面的适用性。在这项研究中，我们报告了脂质体与还原氧化石墨烯 (rGO) 的结合，用于制造用于大肠杆菌 (E. coli) 电化学检测的快速灵敏生物传感器。rGO 的大表面积促进了脂质体与其表面的结合，而固有的电学和生物相容性特性有助于细菌的电化学传感。脂质体和 rGO-脂质体涂层电极的电化学响应分别显示出非导电和导电特性。仅在玻碳电极 rGO-脂质体 (GCE-L-rGO) 表面观察到微分脉冲伏安法的峰值电流随着电解质中细菌密度的逐渐变化而发生显着变化。对于从 3 × 103 到 3 × 104 个细胞/ml 的不同细胞密度，GCE-L-rGO 传感器的检测灵敏度为 ~26 μA/106 个细胞/ml 电解质。所提出的传感技术可以作为传统方法的替代方法，用于快速和原位检测不同样品中的细菌载量，为临床诊断的新应用奠定基础。