Dithiobis(succinimidyl propionate) modified gold microarray electrode based electrochemical immunosensor for ultrasensitive detection of cortisol.

Gold microelectrode arrays functionalized with Dithiobis(succinimidyl propionate) self-assembled monolayer (SAM) have been used to fabricate an ultrasensitive, disposable, electrochemical cortisol immunosensor. Cortisol specific monoclonal antibody (C-Mab) was covalently immobilized on the surface of gold microelectrode array and the sensors were exposed to solutions with different cortisol concentration. After C-Mab binding, unreacted active groups of DTSP were blocked using ethanol amine (EA) and label-free electrochemical impedance (EIS) technique was used to determine cortisol concentration. EIS results confirmed that EA/C-Mab/DTSP/Au based biosensor can accurately detect cortisol in the range of 1 pM to 100 nM. The biosensor was successfully used for measurement of cortisol in interstitial fluid in-vitro. This research establishes the feasibility of using impedance based biosensor architecture for disposable, wearable cortisol detector.

用二硫代双（丙酸琥珀酰亚胺酯）自组装单层（SAM）功能化的金微电极阵列已被用于制造一种超灵敏、一次性的电化学皮质醇免疫传感器。皮质醇特异性单克隆抗体（C - Mab）被共价固定在金微电极阵列表面，并且传感器暴露于具有不同皮质醇浓度的溶液中。在C - Mab结合之后，使用乙醇胺（EA）封闭二硫代双（丙酸琥珀酰亚胺酯）（DTSP）未反应的活性基团，并使用无标记电化学阻抗（EIS）技术来测定皮质醇浓度。电化学阻抗谱结果证实，基于乙醇胺/皮质醇单克隆抗体/二硫代双（丙酸琥珀酰亚胺酯）/金的生物传感器能够准确检测1皮摩尔到100纳摩尔范围内的皮质醇。该生物传感器已成功用于体外间质液中皮质醇的测量。这项研究确立了使用基于阻抗的生物传感器架构来制造一次性、可穿戴皮质醇检测器的可行性。