A label-free electrochemical progesterone (P4) aptasensor was successfully developed by covalently immobilizing NH2-functionalized P4-specific aptamer on the electrode surface. The NiO-Au hybrid nanofibers were synthesized by the electrospinning technique. GQDs-NiO-AuNFs nanocomposite was prepared by dispersing of electrospun NiO-AuNFs in the as-synthesized graphene quantum dots (GQDs) solution and stirring for 24 h. Novel GQDs-NiO-AuNFs nano-architecture in combination with functionalized multiwalled carbon nanotubes (f-MWCNTs) were further utilized to modify screen printed carbon electrode (SPCE) in order to construct an effective immobilization matrix with plenty of carboxylic functional groups. The stepwise assembly process of the designed aptasensor was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The aptamer-progesterone complex formation led to a hindered electron transfer reaction on the sensing interface, which decreased the redox probe peak current. Based on of this, progesterone could be quantitatively detected by monitoring the decrease of differential pulse voltammetric (DPV) responses of [Fe(CN)6]3-/4- peak current with increasing the progesterone concentration. Under optimized experimental parameters, the aptasensor exhibited a dynamic concentration range from 0.01 to 1000 nM and a detection limit of 1.86 pM. The proposed aptasensor was successfully employed for the determination of progesterone in human serum samples and pharmaceutical formulations.

中文翻译：

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用于生物流体中孕酮检测的无标记电化学适体传感器。

通过将NH2官能化的P4特异性适体共价固定在电极表面上，成功开发了无标记的电化学孕酮（P4）适体传感器。通过电纺技术合成了NiO-Au杂化纳米纤维。通过将电纺NiO-AuNFs分散在刚合成的石墨烯量子点（GQDs）溶液中并搅拌24小时来制备GQDs-NiO-AuNFs纳米复合材料。新型GQDs-NiO-AuNFs纳米结构与功能化的多壁碳纳米管（f-MWCNTs）相结合，进一步用于修饰丝网印刷碳电极（SPCE），以构建具有大量羧基官能团的有效固定基质。通过循环伏安法（CV）和电化学阻抗谱（EIS）对所设计的适体传感器的逐步组装过程进行了表征。适体-孕酮复合物的形成导致传感界面上的电子转移反应受阻，从而降低了氧化还原探针的峰值电流。基于此，可以通过监测[Fe（CN）6] 3- / 4-峰值电流随孕酮浓度的升高而降低的差分脉冲伏安（DPV）响应的降低来定量检测孕酮。在优化的实验参数下，适体传感器的动态浓度范围为0.01到1000 nM，检测极限为1.86 pM。所提出的适体传感器已成功用于测定人血清样品和药物制剂中的孕酮。孕酮可以通过监测随着孕酮浓度增加[Fe（CN）6] 3- / 4-峰值电流的差分脉冲伏安（DPV）响应的降低而定量检测。在优化的实验参数下，适体传感器的动态浓度范围为0.01到1000 nM，检测极限为1.86 pM。所提出的适体传感器已成功用于测定人血清样品和药物制剂中的孕酮。可以通过监测[Fe（CN）6] 3- / 4-峰值电流的差分脉冲伏安（DPV）响应随孕酮浓度增加的降低而定量检测孕酮。在优化的实验参数下，适体传感器的动态浓度范围为0.01到1000 nM，检测极限为1.86 pM。所提出的适体传感器已成功用于测定人血清样品和药物制剂中的孕酮。