Institute of Biological Information Processing, Bioelectronics (IBI-3), Forschungszentrum Jülich GmbH, 52428 Jülich, Germany.
Faculty I, RWTH Aachen University, 52062 Aachen, Germany.
Biosensors (Basel). 2023 Sep 11;13(9):881. doi: 10.3390/bios13090881.
Accurate determination of serotonin (ST) provides insight into neurological processes and enables applications in clinical diagnostics of brain diseases. Herein, we present an electrochemical aptasensor based on truncated DNA aptamers and a polyethylene glycol (PEG) molecule-functionalized sensing interface for highly sensitive and selective ST detection. The truncated aptamers have a small size and adopt a stable stem-loop configuration, which improves the accessibility of the aptamer for the analyte and enhances the sensitivity of the aptasensor. Upon target binding, these aptamers perform a conformational change, leading to a variation in the Faraday current of the redox tag, which was recorded by square wave voltammetry (SWV). Using PEG as blocking molecules minimizes nonspecific adsorption of other interfering molecules and thus endows an enhanced antifouling ability. The proposed electrochemical aptamer sensor showed a wide range of detection lasting from 0.1 nM to 1000 nM with a low limit of detection of 0.14 nM. Owing to the unique properties of aptamer receptors, the aptasensor also exhibits high selectivity and stability. Furthermore, with the reduced unspecific adsorption, assaying of ST in human serum and artificial cerebrospinal fluid (aCSF) showed excellent performance. The reported strategy of utilizing antifouling PEG describes a novel approach to building antifouling aptasensors and holds great potential for neurochemical investigations and clinical diagnosis.
准确测定 5-羟色胺（ST）可深入了解神经过程，并能应用于脑疾病的临床诊断。在此，我们提出了一种基于截断 DNA 适体和聚乙二醇（PEG）分子功能化传感界面的电化学适体传感器，用于高度敏感和选择性的 ST 检测。截断适体具有较小的尺寸，并采用稳定的茎环结构，这提高了适体对分析物的可及性，并增强了适体传感器的灵敏度。在靶标结合后，这些适体发生构象变化，导致氧化还原标记物的法拉第电流发生变化，这可通过方波伏安法（SWV）记录。使用 PEG 作为阻断分子可最大程度地减少其他干扰分子的非特异性吸附，从而赋予其增强的抗污能力。所提出的电化学适体传感器具有从 0.1 nM 到 1000 nM 的宽检测范围，检测下限低至 0.14 nM。由于适体受体的独特性质，该适体传感器还表现出高选择性和稳定性。此外，由于非特异性吸附减少，在人血清和人工脑脊液（aCSF）中测定 ST 显示出优异的性能。利用抗污 PEG 的报道策略描述了构建抗污适体传感器的新方法，对于神经化学研究和临床诊断具有巨大的潜力。
