Bliem Christina, Piccinini Esteban, Knoll Wolfgang, Azzaroni Omar
AIT Austrian Institute of Technology GmbH, Biosensor Technologies, Vienna, Austria.
INIFTA Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)-Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata-CONICET, La Plata, Argentina.
Methods Enzymol. 2018;609:23-46. doi: 10.1016/bs.mie.2018.06.001. Epub 2018 Aug 20.
Electrochemical sensors represent a powerful tool for real-time measurement of a variety of analytes of much significance to different areas, ranging from clinical diagnostics to food technology. Point-of-care devices which can be used at patient bedside or for online monitoring of critical parameters are of great importance in clinical daily routine. In this work, portable, low-cost electrochemical sensors for a fast and reliable detection of the clinically relevant analyte urea have been developed. The intrinsic pH sensitivity of reduced graphene oxide (rGO)-based field-effect transistors (FETs) was exploited to monitor the enzymatic hydrolysis of urea. The functionalization of the sensor platform using the layer-by-layer technique is especially advantageous for the immobilization of the biorecognition element provided that this approach preserves the enzyme integrity as well as the rGO surface. The great selectivity of the enzyme (urease) combined with the high sensitivity of rGO-based FETs result in the construction of urea biosensors with a limit of detection (LOD) of 1μM and a linear range up to 1mM. Quantification of Cu with a LOD down to 10nM was performed by taking advantage of the specific inhibition of urease in the presence of heavy metals. These versatile biosensors offer great possibilities for further development of highly sensitive enzyme-based FETs for real-time, label-free detection of a wide variety of clinically relevant analytes.
电化学传感器是一种强大的工具，可用于实时测量对不同领域具有重要意义的各种分析物，从临床诊断到食品技术。可在患者床边使用或用于在线监测关键参数的即时检测设备在临床日常工作中非常重要。在这项工作中，已开发出用于快速可靠检测临床相关分析物尿素的便携式、低成本电化学传感器。利用还原氧化石墨烯（rGO）基场效应晶体管（FET）的固有pH敏感性来监测尿素的酶促水解。使用逐层技术对传感器平台进行功能化对于固定生物识别元件特别有利，前提是这种方法能保持酶的完整性以及rGO表面。酶（脲酶）的高选择性与rGO基FET的高灵敏度相结合，构建出检测限（LOD）为1μM、线性范围高达1mM的尿素生物传感器。通过利用重金属存在下脲酶的特异性抑制作用，实现了检测限低至10nM的铜的定量分析。这些多功能生物传感器为进一步开发用于实时、无标记检测各种临床相关分析物的高灵敏度酶基FET提供了巨大可能性。
