Dopamine (DA) is an important neurotransmitter associated with many diseases. It is very significant to detect DA with high sensitivity and good selectivity. Here, a sensitive and selective electrogenerated chemiluminescence (ECL) aptasensing method was developed for the determination of DA based on target-induced conformational displacement. An anti-DA specific aptamer spliting into two ss-DNA (S1 and S2) was used as molecular recognition elements while an ss-DNA labeled with ferrocene (Fc-CS1, complementary to S1) was used as quenching probe. An ECL platform was prepared by dropping the mixture of Nafion, gold nanoparticles (AuNPs) and Ru(bpy)₃²⁺ onto glassy carbon electrode (GCE). After hybridization of S1 and Fc-CS1, ds-DNA (S1-CS1-Fc) was self-assembled onto the ECL platform to form an ECL aptasensing platform. In the presence of DA and S2, a S1-S2-DA complex was formed and then Fc-CS1 was released from the electrode surface, resulting in an increase of ECL intensity. DA can be sensitively detected in the range of 1.0 × 10^-9 M to 5 × 10^-8 M with a lower detection limit of 0.32 nM. This is first report of ECL aptasensing method for the determination of DA based on target-induced conformational displacement. The proposed ECL aptasensing method, exploiting both the aptamer recognition and ECL detection, allows direct detection of DA in diluted serum samples with high sensitivity and good selectivity, which may be further applicable in other neurochemicals assay and biomedical research.

多巴胺（DA）是与许多疾病相关的重要神经递质。以高灵敏度和良好的选择性检测DA具有非常重要的意义。在这里，开发了一种灵敏且选择性的电致化学发光 (ECL) 适配传感方法，用于基于目标诱导的构象位移测定 DA。分裂成两个 ss-DNA（S1 和 S2）的抗 DA 特异性适体用作分子识别元件，而用二茂铁（Fc-CS1，与 S1 互补）标记的 ss-DNA 用作淬灭探针。通过滴加 Nafion、金纳米粒子 (AuNPs) 和 Ru(bpy) ₃ ^{2+的混合物制备 ECL 平台}玻璃碳电极 (GCE) 上。S1与Fc-CS1杂交后，ds-DNA（S1-CS1-Fc）自组装到ECL平台上，形成ECL适配感应平台。在 DA 和 S2 的存在下，形成 S1-S2-DA 复合物，然后 Fc-CS1 从电极表面释放，导致 ECL 强度增加。DA 可在 1.0 × 10 ^-9 M 至 5 × 10 ^{-8范围内灵敏检测}M，检测下限为 0.32 nM。这是基于目标诱导构象位移测定 DA 的 ECL 适体传感方法的首次报道。所提出的ECL适体传感方法，利用适体识别和ECL检测，可以直接检测稀释血清样品中的DA，灵敏度高，选择性好，可进一步应用于其他神经化学物质测定和生物医学研究。