In this work, we reported the synthesis of 3, 6-diamino-9-ethylcarbazole and its application as a new monomer for preparation of molecularly imprinted polymer (MIP) electrochemical sensor. The as prepared MIP sensor exhibited ultrahigh sensitivity and selectivity for the detection of 17-β-estradiol in attomolar levels (1 × 10^–18 mol L⁻¹). The sensor works by detecting the change of the interfacial impedance that is derived from recognition of 17-β-estradiol on the MIP layer. The MIP sensor based on 3, 6-diamino-9-ethylcarbazole monomer revealed better performance than that of unmodified carbazole monomer. The monomer/template ratio, electropolymerization scanning cycles, and the incubation pH values were optimised in order to obtain the best detection efficiency. Under the optimised condition, the MIP sensor exhibits a wide linear range from 1 aM to 10 μM (1 × 10^–18 ̶ 1 × 10⁻⁵ mol L⁻¹). A low detection limit of 0.36 aM (3.6 × 10^–19 mol L⁻¹) and a good selectivity towards structurally similar compounds were obtained. The proposed MIP sensor also exhibits long-term stability and applicability in human serum samples. These advantages enabled this MIP sensor to be a promising alternative of electrochemical sensor and may be extended to detection of other endogenous compounds.

在这项工作中，我们报告了3，6-二氨基-9-乙基咔唑的合成及其作为制备分子印迹聚合物（MIP）电化学传感器的新单体的应用。所制备的MIP传感器具有超高的灵敏度和选择性，可检测到17原子-β-雌二醇的摩尔浓度（1×10 ^–18  mol L ^-1）。该传感器通过检测从MIP层上的17-β-雌二醇的识别得出的界面阻抗的变化来工作。基于3，6-二氨基-9-乙基咔唑单体的MIP传感器比未改性的咔唑单体具有更好的性能。为了获得最佳检测效率，对单体/模板比，电聚合扫描周期和孵育pH值进行了优化。在优化的条件下，MIP传感器表现出宽线性范围从上午01时至10μM（1×10 ^-18 ̶1×10 ^-5 摩尔大号^-1）。0.36 aM（3.6×10 ^–19  mol L ^-1的低检测限），并且对结构相似的化合物具有良好的选择性。拟议中的MIP传感器在人血清样品中也具有长期稳定性和适用性。这些优点使该MIP传感器成为电化学传感器的有希望的替代品，并可扩展到其他内源性化合物的检测。