Noble metal nanoparticles possess excellent optical and electrical properties, and have been widely used in the construction of biosensors and in surface-enhanced spectroscopy. Herein, we describe an enzyme-assisted ultra-sensitive biosensor with gold nanoparticle (GNP) dimers, based on a localized surface plasmon resonance (LSPR)-enhanced electrochemiluminescence (ECL) mechanism. CdS nanocrystals (NCs) acted as ECL emitters, and the GNP dimers were constructed by hybridization of DNA strands on the surface of an electrode modified with CdS NCs after an enzyme-assisted cyclic amplification process. The plasmon-coupling-induced electromagnetic field enhancement effects of the GNP dimers resulted in an increase in ECL intensity of as much as 6.3-fold under optimized conditions. Based on this LSPR-ECL sensor platform, the detection limit for microRNA-21 is as low as 3.6 fM with a wide linear range from 10 fM to 20 pM with good sensitivity and selectivity.

贵金属纳米粒子具有出色的光学和电学性质，已被广泛用于生物传感器的构造和表面增强光谱学中。在本文中，我们基于局部表面等离振子共振（LSPR）增强的电化学发光（ECL）机制，描述了具有金纳米颗粒（GNP）二聚体的酶辅助超灵敏生物传感器。CdS纳米晶体（NCs）充当ECL发射体，在酶辅助循环扩增过程后，通过用CdS NCs修饰的电极表面上的DNA链杂交，构建了GNP二聚体。在优化条件下，GNP二聚体的等离激元耦合诱导的电磁场增强作用导致ECL强度增加了6.3倍。基于此LSPR-ECL传感器平台，