A highly sensitive catecholamine (CA) sensor was created using a biointerface layer composed of a biopolymer and a potentiometric detection device. For the detection of CAs, 3-aminophenylboronic acid (3-NH₂-PBA) was reacted with the carboxyl side chain of l-3,4-dihydroxyphenylalanine (l-dopa, LD) and the PBA-modified l-dopa was directly copolymerized with LD on an Au electrode, resulting in a 3.5 nm thick PBA-modified poly(PBA–LD/LD) layer-coated Au electrode. By connecting the PBA–LD-coated Au electrode to a field-effect transistor (FET), the molecular charge changes at the biointerface of the Au electrode, which was caused by di-ester binding of the PBA–CA complex, were transduced into gate surface potential changes. Effective CAs included LD, dopamine (DA), norepinephrine (NE), and epinephrine (EP). The surface potential of the PBA–LD-coated Au changed after the addition of 40 nM of each CA solution; notably, the PBA–LD-coated Au showed a higher sensitivity to LD because the surface potential change could already be observed after 1 nM of LD was added. The fundamental parameter analyses of the PBA–LD to CA affinity from the surface potential shift against each CA concentration indicated the highest affinity to LD (binding constant (K_s): 1.68 × 10⁶ M^–1, maximum surface potential shift (V_max): 182 mV). Moreover, the limit of detection for each CA was 3.5 nM in LD, 12.0 nM in DA, 7.5 nM in NE, and 12.6 nM in EP. From these results, it is concluded that the poly(PBA–LD/LD)-coated gate FET could become a useful biosensor for neurotransmitters, hormones, and early detection of Parkinson’s disease.

中文翻译：

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使用功能化的聚（1-多巴）涂层栅场效应晶体管检测邻苯二酚

使用由生物聚合物和电位检测设备组成的生物界面层创建了高度敏感的儿茶酚胺（CA）传感器。用于检测的CA，3-氨基苯基硼酸（3-NH ₂ -PBA）用的羧基侧链反应升二羟基苯-3,4-（升-DOPA，LD）和PBA-改性升-dopa与LD在Au电极上直接共聚，得到3.5 nm厚的PBA改性的聚（PBA-LD / LD）涂层Au电极。通过将涂有PBA-LD的Au电极连接到场效应晶体管（FET），可以将由于PBA-CA复合物的二酯键合而引起的Au电极生物界面上的分子电荷变化转化为栅极表面电势变化。有效的CA包括LD，多巴胺（DA），去甲肾上腺素（NE）和肾上腺素（EP）。在每种CA溶液中添加40 nM后，PBA-LD涂层的Au的表面电势发生了变化。值得注意的是，涂有PBA-LD的Au对LD的敏感性更高，因为在添加1 nM LD后已经可以观察到表面电势的变化。K _s）：1.68×10 ⁶ M ^–1，最大表面电势偏移（V _max）：182 mV）。此外，每个CA的检出限在LD中为3.5 nM，在DA中为12.0 nM，在NE中为7.5 nM，在EP中为12.6 nM。从这些结果可以得出结论，聚（PBA-LD / LD）涂层的栅极FET可能成为神经递质，激素和帕金森氏病早期检测的有用生物传感器。