Staphylococcal food poisoning is one of the most commonly encountered foodborne illnesses that results from the consumption of foods containing staphylococcal enterotoxins (SEs) produced by enterotoxigenic strains of Staphylococcus aureus. Among the SEs, staphylococcal enterotoxin B (SEB) is one of the most commonly presented serotypes in staphylococcal food-poisoning cases, and rapid, accurate, and reliable detection of SEB is necessary and significant to protect public health from SEB. Herein, a label-free and convenient aptamer-based electrochemical biosensor for SEB detection was explored. In the absence of SEB, only the aptamer and mercaptohexanol (MCH) assembled on electrode surfaces, resulting in an efficient electron transfer and a small faradaic impedance response of [Fe(CN)₆]^3−/4−. Upon the addition of SEB, SEB assembled on gold electrode surfaces owing to the high specific recognition and affinity constants of the aptamer and SEB. In this state, the electron transfer of [Fe(CN)₆]^3−/4− was greatly inhibited, due to SEB on gold electrode surfaces which prevents [Fe(CN)₆]^3−/4− from accessing the electrode surface for efficient electron transfer, and a large faradaic impedance response of [Fe(CN)₆]^3−/4− was obtained. [Fe(CN)₆]^3−/4− was used as the redox probe to evaluate the interfacial electron transfer resistance of the biosensor, and the change in R_et against the logarithm of SEB concentration was found to be linear over the range from 0.5 ng mL⁻¹ to 500 ng mL⁻¹, with a detection limit of 0.17 ng mL⁻¹ (S/N = 3). In order to demonstrate the applicability and reliability of the proposed method in complex matrices such as milk samples, the results of this assay and the ELISA kit were compared. The relative percentage error between the two methods ranged from −8.38 to 8.33, which indicates that there is no significant difference between the results obtained by the two methods. It also indicates that the proposed method holds great promise for real sample detection.

中文翻译：

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基于适体的电化学生物传感器，用于牛奶中葡萄球菌肠毒素B的简单而灵敏的检测

葡萄球菌食物中毒是最常见的食源性疾病之一，其原因是食用了由金黄色葡萄球菌肠毒素菌株产生的含有葡萄球菌肠毒素（SEs）的食物。在SE中，葡萄球菌肠毒素B（SEB）是在葡萄球菌食物中毒病例中最常见的血清型之一，对SEB进行快速，准确和可靠的检测对于保护公众健康免受SEB来说是必要且重要的。在本文中，探索了一种无标记且方便的基于适体的电化学生物传感器，用于SEB检测。在没有SEB的情况下，仅适体和巯基己醇（MCH）组装在电极表面上，导致有效的电子转移和[Fe（CN）₆的小的法拉第阻抗响应] ^{3− / 4−}。加入SEB后，由于适体和SEB的高特异性识别和亲和常数，SEB组装在金电极表面上。在这种状态下，电子转移的[Fe（CN）₆ ] ^{3- / 4-}大大抑制，由于在金电极表面SEB其防止的[Fe（CN）₆ ] ^{3- / 4-}访问该电极表面为了有效的电子转移，获得了大的[Fe（CN）₆ ] ^{3- / 4-的}法拉第阻抗响应。[Fe（CN）₆ ] ^{3- / 4-}被用作氧化还原探针，以评估生物传感器的界面电子转移电阻和R的变化_相对于SEB浓度的对数的等值线在0.5 ng mL ^-1至500 ng mL ^-1的范围内呈线性，检出限为0.17 ng mL ^-1（S / N = 3）。为了证明该方法在复杂基质（如牛奶样品）中的适用性和可靠性，对本测定结果和ELISA试剂盒进行了比较。两种方法之间的相对百分比误差范围为-8.38至8.33，这表明两种方法获得的结果之间没有显着差异。这也表明该方法对实际样品的检测具有广阔的前景。