The routinely used enzymes, antibodies, and nucleic acids-based biosensors for detection of Staphylococcus aureus are often overwhelmed by limited selectivity, sensitivity, high cost, and inability to discriminate between live/dead cells. This necessitates the development of an ultra-sensitive, stable, and selective electrochemical biosensor capable of discriminating live S. aureus in a mixture of live/dead cells in food samples. The current study reports the development of an electrochemical biosensor through the immobilization of bacteriophage in surface-modified bacterial cellulose (BC) matrix. BC being highly porous and fibrous, offers a high surface area for the impregnation of carboxylated multiwalled carbon nanotubes (c-MWCNTs) and allows high-density phage immobilization. Surface modification of BC/c-MWCNTs with polyethyleneimine (PEI) provides a positive charge that facilitates oriented phage immobilization. FE-SEM and FT-IR analyses confirmed the development of BC/c-MWCNTs-PEI-phage bio-interface. Confocal microscopy analysis showed 11.7 ± 1.2 phage particles⋅μm^-2 immobilized in the BC matrix and showed anti-staphylococcal activity by producing clear lytic zone and reduced bacterial growth. Differential pulse voltammetry (DPV) analysis detected 3 CFU⋅mL^-1 and 5 CFU⋅mL^-1 of S. aureus in phosphate buffer saline (PBS) and milk, respectively, within 30 min at neutral pH and showed stability over 6-weeks at 4 °C. The biosensor showed high specificity for S. aureus, both in pure and mixed cultures of non-host bacteria, and effectively discriminated live S. aureus in a mixture of live/dead cells. The developed biosensor represents a simple, sensitive, specific, and accurate tool for early detection of S. aureus in food samples.

用于检测金黄色葡萄球菌的常规使用的酶，抗体和基于核酸的生物传感器常常因选择性，灵敏度，成本高以及无法区分活/死细胞而被淹没。这需要开发能够区分活金黄色葡萄球菌的超灵敏，稳定和选择性的电化学生物传感器。食物样品中活细胞/死细胞的混合物。当前的研究报道了通过将噬菌体固定在表面修饰的细菌纤维素（BC）基质中的电化学生物传感器的发展。BC具有高度的多孔性和纤维性，为浸渍羧化多壁碳纳米管（c-MWCNT）提供了较大的表面积，并允许高密度的噬菌体固定化。用聚乙烯亚胺（PEI）对BC / c-MWCNT进行表面修饰可提供正电荷，有助于定向噬菌体的固定。FE-SEM和FT-IR分析证实了BC / c-MWCNTs-PEI-噬菌体生物界面的发展。共聚焦显微镜分析显示11.7±1.2噬菌体颗粒·μm ^-2固定在BC基质中，并通过产生清晰的裂解区和减少细菌生长而显示出抗葡萄球菌活性。差示脉冲伏安法（DPV）分析在中性pH值下在30分钟内分别在磷酸盐缓冲液（PBS）和牛奶中检测到3 CFU·mL ^-1和5 CFU · mL ^-1的金黄色葡萄球菌，并在6周内显示出稳定性在4°C下。该生物传感器在非宿主细菌的纯培养物和混合培养物中均显示出对金黄色葡萄球菌的高特异性，并有效区分了活/死细胞混合物中的活金黄色葡萄球菌。先进的生物传感器代表了一种用于食品样品中金黄色葡萄球菌早期检测的简单，灵敏，特异和准确的工具。