Ahmadian-Alam Leila, Andrade Arturo, Song Edward
Department of Electrical & Computer Engineering, University of New Hampshire, Durham, NH 03824, United States.
Department of Neuroscience, Brown University, Providence, RI 02912, United States.
ACS Appl Polym Mater. 2024 May 24;6(10):5630-5641. doi: 10.1021/acsapm.4c00121. Epub 2024 May 10.
Glutamate (Glu) and histamine (His) are two major neurotransmitters that play many critical roles in brain physiological functions and neurological disorders. Therefore, specific and sensitive monitoring of Glu and His is essential in the diagnosis and treatment of various mental health and neurodegenerative disorders. Both being non-electroactive species, direct electrochemical detection of Glu and His has been challenging. Herein, we report a stimuli-responsive polymer-based biosensor for the electrochemical detection of Glu and His. The polymer-based target receptors consist of a linear chain stimuli-responsive templated polymer hybrid that is labeled with an osmium-based redox-active reporter molecules to elicit conformation-dependent electrochemical responses. The polymers are then attached to a gold electrode to implement an electrochemical sensor. The cyclic voltammetry (CV) and square-wave voltammetry (SWV) results confirmed the polymers' conformational changes due to the specific target (i.e., Glu and His) recognition and the corresponding electrochemical detection capabilities. The voltammetry results indicate that this biosensor can be used as a 'signal-on' and 'signal-off' sensors for the detection of Glu and His concentrations, respectively. The developed biosensor also showed excellent regeneration capability by fully recovering the initial current signal after rinsing with deionized water. To further validate the polymer's utility as a target bioreceptor, the surface plasmon resonance (SPR) technique was used to characterize the binding affinity between the designed polymers and the target chemical. The SPR results exhibited the equilibrium dissociation constants (K) of 2.40 μM and 1.54 μM for the polymer-Glu and polymer-His interactions, respectively. The results obtained this work strongly suggest that the proposed sensing technology could potentially be used as a platform for monitoring non-electroactive neurochemicals from animal models.
谷氨酸（Glu）和组胺（His）是两种主要的神经递质，在大脑生理功能和神经疾病中发挥着许多关键作用。因此，对Glu和His进行特异性和灵敏的监测对于各种心理健康和神经退行性疾病的诊断和治疗至关重要。由于二者均为非电活性物质，对Glu和His进行直接电化学检测一直具有挑战性。在此，我们报道了一种基于刺激响应聚合物的生物传感器，用于对Glu和His进行电化学检测。基于聚合物的靶标受体由线性链刺激响应模板聚合物杂化物组成，该杂化物用基于锇的氧化还原活性报告分子标记，以引发构象依赖性电化学响应。然后将这些聚合物附着到金电极上以实现电化学传感器。循环伏安法（CV）和方波伏安法（SWV）结果证实了由于特异性靶标（即Glu和His）识别导致的聚合物构象变化以及相应的电化学检测能力。伏安法结果表明，该生物传感器可分别用作检测Glu和His浓度的“信号开启”和“信号关闭”传感器。所开发的生物传感器在用去离子水冲洗后通过完全恢复初始电流信号还显示出优异的再生能力。为了进一步验证该聚合物作为靶标生物受体的效用，使用表面等离子体共振（SPR）技术来表征所设计的聚合物与靶标化学物质之间的结合亲和力。SPR结果显示聚合物与Glu和聚合物与His相互作用的平衡解离常数（K）分别为2.40 μM和1.54 μM。这项工作获得的结果强烈表明，所提出的传感技术有可能用作监测动物模型中非电活性神经化学物质的平台。
