Dopamine plays an essential role in the proper functioning of the brain and the body. A change in the level of dopamine can lead to disorders related to the nervous system. Thus, detection of dopamine levels may aid in the diagnosis and treatment of various diseases. Enzymatic electrochemical sensors have been extensively studied for the detection of dopamine because they exhibit excellent selectivity and reliability. However, enzymatic electrochemical sensors suffer from several unavoidable drawbacks such as complex enzyme purification process, weak enzyme immobilization on the electrode, enzyme denaturation and low stability. On the other hand, non-enzymatic sensors are promising alternatives that offer high sensitivity, high electrocatalytic activity, long term stability and eliminate the problems associated with enzymes. Herein, we present a non-enzymatic nanocomposite (NC) of metal oxides (CuO-MgO) for efficient electrochemical detection of dopamine. Scalable sol-gel method is adopted for the controlled growth of CuO-MgO NC. The structural, elemental and morphological analysis is performed by XRD, Raman spectroscopy, and TEM characterization, respectively. The electrochemical analysis was carried out to study the electrocatalytic behavior of CuO-MgO in the detection of dopamine, by cyclic voltammetry and chronoamperometric methods. The electrocatalytic behavior was investigated at different scan rates and for different dopamine concentrations in artificial sweat solution. The CuO-MgO NC catalyst exhibited a sensitivity of $69~\mu $ Acm−2mM−1 and the detection limit is computed to be $6.4~\mu \text{M}$ in the linear range of 10- $100~\mu \text{M}$ . Moreover, the NC apprehended a high degree of selectivity towards other bio-compounds present in the sweat, and no possible interfering cross-reaction from these species was observed. The as-synthesized CuO-MgO NC offered high sensitivity, selectivity, fast response and stability, which benchmarked its potential for dopamine sensing.

中文翻译：

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用于多巴胺检测的基于 CuO-MgO 复合材料的非酶电化学传感器


多巴胺在大脑和身体的正常运作中起着至关重要的作用。多巴胺水平的变化可能导致与神经系统相关的疾病。因此，多巴胺水平的检测可能有助于各种疾病的诊断和治疗。酶电化学传感器已被广泛研究用于检测多巴胺，因为它们具有出色的选择性和可靠性。然而，酶电化学传感器存在一些不可避免的缺点，如酶纯化过程复杂、酶在电极上的固定性弱、酶变性和稳定性低。另一方面，非酶传感器是有前途的替代品，它具有高灵敏度、高电催化活性、长期稳定性并消除了与酶相关的问题。在此，我们提出了一种金属氧化物（CuO-MgO）的非酶纳米复合材料（NC），用于有效电化学检测多巴胺。采用可扩展的溶胶-凝胶方法来控制 CuO-MgO NC 的生长。分别通过 XRD、拉曼光谱和 TEM 表征进行结构、元素和形态分析。采用循环伏安法和计时电流法进行电化学分析，研究了 CuO-MgO 在检测多巴胺中的电催化行为。研究了人工汗液中不同扫描速率和不同多巴胺浓度下的电催化行为。 CuO-MgO NC催化剂的灵敏度为$69~\mu $ Acm−2mM−1，在10- $100~\mu \的线性范围内计算出检测限为$6.4~\mu \text{M}$文本{M}$ 。 此外，NC 对汗液中存在的其他生物化合物具有高度选择性，并且没有观察到来自这些物种的可能的干扰交叉反应。合成的 CuO-MgO NC 具有高灵敏度、选择性、快速响应和稳定性，这证明了其在多巴胺传感方面的潜力。