Novel exciton–plasmon interactions (EPI) between [email protected]₃N₄ heterojunction and [email protected] nanoparticles (NPs) was introduced for the first time into the photoelectrochemical (PEC) biosensing system for highly sensitive microRNA-21 detection using duplex-specific nuclease-assisted cycle amplification for sensitivity enhancement. The photoelectrode of [email protected]₃N₄ nanowires could generate a great photocurrent because of the formation of the p–n heterojunction. Due to the natural absorption overlap, the exciton of [email protected]₃N₄ and the plasmon of [email protected] NPs could be induced simultaneously to form EPI. Specifically, the perfect overlap of the wide absorption spectrum of [email protected] NPs with the photoluminescence spectrum of [email protected]₃N₄ allows the resonance energy transfer and EPI between [email protected]₃N₄ nanowire and [email protected] NPs simultaneously. The effective EPI renders the signal change modulated by the interparticle distance significantly. Such a signaling mechanism was then used to construct the PEC biosensor for microRNA-21 detection, within which the duplex-specific nuclease (DSN) was further introduced to enhance the sensitivity. The constructed PEC biosensor exhibits the sub-fM level (0.05 fM) detection of microRNA-21 with a wide range from 0.1 fM to 1.0 nM. In complex biological samples, the proposed method also possesses good specificity, reproducibility, and stability.

中文翻译：

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[电子邮件保护] ₃ N ₄异质结与[电子邮件保护]纳米粒子之间的激子-等离子体相互作用与DNAase触发的信号放大耦合：迈向MicroRNA的高灵敏度光电化学生物分析。

[电子邮件保护的] ₃ N ₄异质结与[电子邮件保护的]纳米粒子（NP ）之间的新型激子-等离子体激元相互作用（EPI）首次引入光电化学（PEC）生物传感系统中，用于使用双链反应检测高灵敏度的microRNA-21。特异性核酸酶辅助循环扩增，以提高灵敏度。[ p-n]异质结的形成使[电子邮件保护的] ₃ N ₄纳米线的光电极可以产生很大的光电流。由于自然吸收重叠，激子受[电子邮件保护] ₃ N ₄[email protected] NPs的等离激元可以同时被诱导形成EPI。具体而言，[受电子邮件保护的] NP的宽吸收光谱与[受电子邮件保护的] ₃ N ₄的光致发光光谱的完美重叠允许[受电子邮件保护的] ₃ N ₄之间的共振能量转移和EPI。纳米线和[受电子邮件保护的] NP同时进行。有效的EPI使信号变化受到粒子间距离的调制。然后使用这种信号传导机制构建用于microRNA-21检测的PEC生物传感器，在其中进一步引入双链体特异性核酸酶（DSN）以增强灵敏度。所构建的PEC生物传感器显示出microRNA-21的亚fM水平（0.05 fM）检测范围从0.1 fM到1.0 nM。在复杂的生物样品中，该方法还具有良好的特异性，可重复性和稳定性。