An “off-on-enhanced on” electrochemiluminescence biosensor based on resonance energy transfer and surface plasmon coupled 3D DNA walker for ultra-sensitive detection of microRNA-21

• Published in: Analytica chimica acta 2024-08, Vol.1315, p.342822, Article 342822
• Main Authors: Li, Meng-Li, Zhong, Ming-Yu, Zhang, Jia, Zhang, Yi-Jia, Zhang, Yu-Qi, Liu, Yan, Li, Xiang-Kai, Gan, Shu-Tian, Meng, Gong-Rui, Mi, Li, Hu, Yong-Hong, Zhang, Fang, Zhang, Xiao-Xu, Wang, Yin-Zhu
• Format: Article
• Language: English
• Subjects: Biosensing Techniques - methods; CZIS QDs; DNA - chemistry; Electrochemical Techniques - methods; Electrochemiluminescence; Energy Transfer; Gold - chemistry; Humans; Limit of Detection; Localized surface plasmon resonance; Luminescent Measurements - methods; Metal Nanoparticles - chemistry; MicroRNAs - analysis; MicroRNAs - blood; Quantum Dots - chemistry; Resonance energy transfer; Surface plasmon coupling; Surface Plasmon Resonance - methods
• ISSN: 0003-2670; 1873-4324; 1873-4324
• DOI: 10.1016/j.aca.2024.342822

In this study, a novel electrochemiluminescence (ECL) biosensor was developed to detect microRNA-21 (miRNA-21) with high sensitivity by leveraging the combined mechanisms of resonance energy transfer (RET) and surface plasmon coupling (SPC). Initially, the glassy carbon electrode (GCE) were coated with Cu–Zn–In–S quantum dots (CZIS QDs), known for their defect-related emission suitable for ECL sensing. Subsequently, a hairpin DNA H3 with gold nanoparticles (Au NPs) attached at the end was modified over the surface of the quantum dots. The Au NPs could effectively quench the ECL signals of CZIS QDs via RET. Further, a significant amount of report DNA was generated through the action of a 3D DNA walker. When the report DNA opened H3–Au NPs, the hairpin structure experienced a conformational change to a linear shape, increasing the gap between the CZIS QDs and the Au NPs. Consequently, the localized surface plasmon resonance ECL (LSPR-ECL) effect replaced ECL resonance energy transfer (ECL-RET). Moreover, the report DNA was released following the addition of H4–Au NPs, resulting in the formation of Au dimers and a surface plasma-coupled ECL (SPC-ECL) effect that enhanced the ECL intensity to 6.97-fold. The integration of new ECL-RET and SPC-ECL biosensor accurately quantified miRNA-21 concentrations from 10−8 M to 10−16 M with a limit of detection (LOD) of 0.08 fM, as well as successfully applied to validate human serum samples. When H3–Au NPs were modified over the surface of the CZIS QDs, the Au NPs could effectively quench the ECL signals of CZIS QDs via RET. Further, the space between the CZIS QDs and the Au NPs increased when a large amount of report DNA produced by the 3D DNA walker opened the H3–Au NPs, resulting in the LSPR-ECL effect rather than the ECL-RET. After the addition of H4–Au NPs, the report DNA was finally released, causing the production of Au dimers and an SPC-ECL impact. [Display omitted] •A novel ECL biosensor was built for highly sensitive detectioning miRNA-21 by leveraging conversion mechanisms of RET and SPC.•A novel cathodic ECL material (CZIS QDs) along with the 3D DNA walker were employed for miRNA-21 analysis.•The LSPR-ECL effect replaces the ECL-RET effect by varying the distance between CZIS QDs and Au NPs.•The SPC-ECL reaction between CZIS QDs and Au–Au dimers secondary enhanced the ECL signal.