光功能纳米金环孔道的可靠构筑及其单分子检测应用研究

Nanopore-based sensors have broad application potentials in single-molecule and single-particle-level detection and molecular structure analysis due to its ultrahigh sensitivity. However, it is difficult to satisfy the detection requirements of higher sensitivity and accuracy only by monitoring the pulse current signal induced by the ion blocking using biological or solid state nanopores. Nanopores with both optical and electrical functionalities are supposed to have the potential for faster and more accurate detection for molecules and nanoparticles by correlation analysis of ion current and optical signals. Nevertheless, the existing structure system has the disadvantages of fabrication challenge, probe decoration difficulty and poor detection specificity. In this project, we propose a new kind of optically functional nanopores with plasmonic metal structures decorated on their sidewalls. In this system, the nanopores are self-aligned with the plasmonic hot spot, and possess excellent detection capability due to the synergy of electric and optical signals. Furthermore, the probe molecules can be decorated only on the sidewalls of the nanopores via selective molecule-metal bonding, thus significantly improving the detection signal-to-noise ratio and accuracy. By combining the high-end nanofabrication platform of the Microsystem & Terahertz Research Center of the China Academy of Engineering Physics and the high-resolution nanofabrication experience of the applicant at Hunan University, the project aims to realize reliable construction of these new optically functional nanopores and their corresponding arrayed structures. We will also systematically investigate the unique optical and electrical properties of these special structures and their detection capabilities for molecules, based on which the applications in single-molecule level detection will be explored.

纳米孔道传感器件因其高灵敏度，在单分子探测、分子结构分析及纳米粒子检测中具有广泛应用前景。然而，仅通过生物或固态纳米孔道来监测单一的离子阻塞电流脉冲信号已难以满足更灵敏、更准确的检测需求。具备光电协同检测能力的纳米孔道可通过离子电流脉冲信号与分子光信号的关联分析实现更快速、更准确的分子及粒子探测，但目前被研究的结构体系存在加工难度高、探针分子无法定位修饰、检测特异性差等不足。为此，本项目提出一类基于金属圆环结构的光功能纳米孔道。该结构中，纳米孔道与等离激元热点自对准，具有优异的光电协同检测能力，且可仅在孔道内壁的金环表面修饰探针分子，从而大幅提升测试信噪比及精准性。项目借助中物院微太中心工艺平台的大型精密微纳加工设备及申请人积累的高精度纳米加工经验，拟实现这类新型光功能纳米金环孔道及其阵列结构的可靠构筑，深入研究其独特的光电特性及高灵敏的分子检测能力，探索其在单分子尺度与精度检测中的应用。

纳米孔道传感器件因其高灵敏度，在单分子探测、分子结构分析及纳米粒子检测中具有广泛应用前景。但目前被研究的结构体系存在加工难度高、探针分子无法定位修饰、检测特异性差等不足。为此，本项目提出一类基于金属圆环结构的光功能纳米孔道。项目的主要研究内容包括：（1）光功能纳米金环孔道结构的可靠加工和创新工艺开发；（2）光功能纳米金环孔道光电信号检测及应用；（3）以项目为契机，与中物院微太中心建立深度合作，互相赋能，为本项目研究提供更好的平台和技术。.相关成果共发表 SCI 论文 10 篇，其中项目负责人为通讯或者共同通讯作者的 10 篇，包括综合和光学领域公认的顶级期刊论文 Nature Communications 1篇，National Science Review 1篇，Nano Letters 1篇， ACS Applied Materials & Interfaces 1篇。基于本项目的成果和经验，受邀撰写高分辨纳米加工和离子束加工综述两篇，分别发表于International Journal of Extreme Manufacturing和Nanoscale。另外，基于本项目建立的深度合作，依靠微太中心的微纳加工平台，合作发表SCI论文2篇，分别发表于Nano Letters 和Laser Photonics Reviews上。申请发明专利 4 项，在国内外重要学术会议上做口头或邀请报告 10余 次，共培养研究生或者博士后 9 名。取得重要进展包括：（1）开发了临界表面能修饰改性及无损纳米转印技术，实现了大面积的悬空光功能金属纳米孔的可靠制备；（2）开发了离子束抛光工艺，进一步提升了光功能金属纳米孔的表面粗糙度和尺寸均匀性，表面粗糙度控制在1 nm范围；（3）提出了电子束纳米剪纸光刻新策略，极大地拓展了电子束光刻的加工能力，优化了加工工艺，实现了复杂光功能金属纳米孔的高效率加工；（4）实现了光功能金属纳米孔的单分子测试及相关应用，包含拉曼、折射率、透射、光电信号检测；（5）成功与中物院微太中心建立了长期且深度的合作，优势互补，提升了中物院微太中心的研究能力和平台利用价值，同时也拓宽了项目负责人团队的平台使用渠道，目前双方已合作发表SCI论文4篇。本项目从工艺开发、器件应用、合作交流等方面开展研究，项目的顺利实施为光功能纳米孔器件未来的产业化应用提供了技术积累。