To effectively and conveniently detect pathogenic bacteria, this study aimed to develop label-free biosensors fabricated affinity peptides that can recognize targeted bacteria strains and enable precise quantitative detections. A 12-mer peptide with high binding affinity toward Escherichia coli O157:H7 was discovered by biopanning of phage-displayed peptide library. The peptide modified with glycine residues (G3) and one cysteine (C) residue at C-terminal, could self-assemble on gold electrodes, enabling electrochemical impedance spectroscopy (EIS) analysis for quantitative detection of E. coli O157:H7. This method showed a low detection limit of 20 CFU/mL and a liner range from 2 × 102 to 2 × 106 CFU/mL. It appears that, by designing and optimizing the structures of peptides, such a strategy can be greatly promising in developing quick, sensitive and quantitative biosensor of pathogens.

中文翻译：

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用亲和肽制造的阻抗生物传感器可灵敏检测大肠杆菌 O157:H7

为了有效方便地检测病原菌，本研究旨在开发无标记生物传感器制造的亲和肽，可以识别目标细菌菌株并实现精确的定量检测。通过对噬菌体展示肽库进行生物淘选，发现了一种对大肠杆菌 O157:H7 具有高结合亲和力的 12 聚体肽。在 C 端用甘氨酸残基 (G3) 和一个半胱氨酸 (C) 残基修饰的肽可以在金电极上自组装，从而实现电化学阻抗谱 (EIS) 分析，用于定量检测大肠杆菌 O157:H7。该方法显示出 20 CFU/mL 的低检测限和 2 × 102 至 2 × 106 CFU/mL 的衬管范围。看来，通过设计和优化肽的结构，这种策略在快速、