Hydrogen peroxide is a key component of the innate immune response, regulating how a cell responds to a bacterial threat; however, being transient in nature makes it extremely difficult to detect. We show the development of an improved biosensor capable of the rapid detection of the hydrogen peroxide produced intracellularly in response to both smooth and rough lipopolysaccharides (LPS) structures. The arising signal and mass transport behaviour to the electrodes were characterised. This response was detected utilising a single walled carbon nanotube-based sensor that has been functionalised with an osmium complex for specificity and detecting the change in intracellular concentrations of hydrogen peroxide through chronoamperometry. This was conducted within murine macrophage (RAW264.7) cells and using ultra-pure LPS extracted from two different serotypes of bacteria (0111:B4 and Re495). This allowed the comparison of the immune response when infected with different structures of LPS. We demonstrate that the hydrogen peroxide signal can be electrochemically detected within 3 seconds post injection. Combining the nature of the mass transport of hydrogen peroxide and concentration characteristics, a bacterial 'fingerprint' was identified. The impact of this work will be demonstrated in allowing us to develop a rapid diagnostic for bacterial detection.

中文翻译：

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细胞内碳纳米电极传感器检测到的脂多糖诱导的H2O2的大量运输。

过氧化氢是先天性免疫反应的关键组成部分，它调节细胞对细菌威胁的反应方式。但是，由于本质上是瞬态的，因此很难检测到。我们显示了一种改进的生物传感器的发展，该传感器能够快速检测细胞内产生的过氧化氢，以响应光滑和粗糙的脂多糖（LPS）结构。表征了出现的信号和向电极的质量传输行为。利用单壁碳纳米管基传感器检测该响应，该传感器已用配合物进行功能化以实现特异性，并通过计时电流法检测细胞内过氧化氢浓度的变化。这是在鼠巨噬细胞（RAW264。7）细胞，并使用从两种不同血清型的细菌（0111：B4和Re495）中提取的超纯LPS。这样可以比较感染不同结构的LPS时的免疫反应。我们证明过氧化氢信号可以注射后3秒内电化学检测到。结合过氧化氢的大量运输的性质和浓度特征，鉴定出细菌“指纹”。这项工作的影响将在使我们能够开发出用于细菌检测的快速诊断中得到证明。结合过氧化氢的大量运输的性质和浓度特征，鉴定出细菌“指纹”。这项工作的影响将在使我们能够为细菌检测开发快速诊断中得到证明。结合过氧化氢的大量运输的性质和浓度特征，鉴定出细菌“指纹”。这项工作的影响将在使我们能够为细菌检测开发快速诊断中得到证明。