Department of Analytical Chemistry, College of Chemistry, Jilin University, Changchun, 130012, China.
Electron Microscopy Center, Jilin University, Changchun, 130012, China.
Mikrochim Acta. 2020 Oct 9;187(11):599. doi: 10.1007/s00604-020-04584-1.
A tunable plasmon-assisted electrochemiluminescence (ECL) strategy is reported using concave Au nanocubes (Au CBs) for rapidly accelerated fibrosarcoma B-type (BRAF) detection. Concave Au CBs exhibit a strong surface plasmon coupling (SPC) effect between its sharp apexes and edges. The high spectral overlap with graphite phase carbon nitride quantum dots (g-CN QDs) is achieved by tuning surface plasmon absorption peak of the concave Au CBs. It maximizes the SPC effect and enhances the ECL signal of g-CN QDs 3-fold. The SPC effect of Au CBs is twice as high as with Au NPs. We also employed a toehold-mediated strand displacement (TMSD) strategy for sensitive target recycling amplification. Under optimal conditions, this sensor can determine BRAF gene from 1 pM to 1 nM with a detection limit of 3.06 × 10 nM (S/N = 3) and RSD 3.67%. With the aid of the TMSD strategy and tunable plasmon-assisted ECL sensing mode, this sensor also exhibits good analytical performance in human serum with satisfactory recovery of 90.2~109%. The proposed strategy provides a promising method to effectively enhance spectral overlap and detect BRAF gene.
本文报道了一种可调谐的等离子体辅助电化学发光（ECL）策略，该策略使用凹面金纳米立方（Au CBs）来快速加速纤维肉瘤 B 型（BRAF）检测。凹面 Au CBs 在其尖锐顶点和边缘之间表现出很强的表面等离子体耦合（SPC）效应。通过调整凹面 Au CBs 的表面等离子体吸收峰，实现了与石墨相氮化碳量子点（g-CN QDs）的高光谱重叠。这最大限度地提高了 SPC 效应，并将 g-CN QDs 的 ECL 信号增强了 3 倍。Au CBs 的 SPC 效应是 Au NPs 的两倍高。我们还采用了引发链置换（TMSD）策略进行敏感的靶标循环放大。在最佳条件下，该传感器可以从 1 pM 到 1 nM 范围内检测 BRAF 基因，检测限为 3.06 × 10 nM（S/N = 3），RSD 为 3.67%。借助 TMSD 策略和可调谐等离子体辅助 ECL 传感模式，该传感器在人血清中也表现出良好的分析性能，回收率为 90.2%至 109%。该策略为有效增强光谱重叠和检测 BRAF 基因提供了一种有前途的方法。
