State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering , Nanjing University , Nanjing 210023 , China.
School of Physics , Nanjing University , Nanjing 210093 , China.
Anal Chem. 2018 Sep 18;90(18):10786-10794. doi: 10.1021/acs.analchem.8b01715. Epub 2018 Aug 29.
Graphene plasmon has attracted extensive interest due to the unprecedented electromagnetic confinement, long propagation distance, and tunable plasmonic frequency. Successful applications of graphene plasmon as infrared sensors have been recently demonstrated, yet they are mainly focused on solid/solid and solid/gas interfaces analysis. Herein, we, for the first time, propose a graphene plasmon-enhanced infrared sensor based on attenuated total reflection configuration for in situ analysis of aqueous-phase molecules. This IR sensor includes a boron-doped graphene (BG) nanodisk array fabricated on top of a ZnSe prism surface that supports attenuated total reflection surface-enhanced infrared absorption spectroscopy (ATR-SEIRA). Our ATR-SEIRA platform is efficient and straightforward for in situ and label-free monitoring of the interaction of biomolecules without interference from the environments, allowing for the extraction of instant spectroscopic information in a complex biological event. Utilizing the near-field enhancement of graphene plasmon, the binding interaction of L-selectin with its aptamer as a demonstration has been investigated to evaluate the specific protein recognition process. The detection limit of the target protein reaches 0.5 nM. Our work demonstrates that chemical-doped graphene plasmon combined with ATR-SEIRA is a promising signal enhancement platform for in situ aqueous-phase biosensing.
石墨烯等离子体由于其前所未有的电磁限制、长传播距离和可调谐等离子体频率而引起了广泛的关注。最近已经证明了石墨烯等离子体作为红外传感器的成功应用，但它们主要集中在固/固和固/气界面分析上。在这里，我们首次提出了一种基于衰减全反射配置的石墨烯等离子体增强型红外传感器，用于原位分析水相分子。该红外传感器包括在 ZnSe 棱镜表面上制造的硼掺杂石墨烯 (BG) 纳米盘阵列，该纳米盘阵列支持衰减全反射表面增强红外吸收光谱 (ATR-SEIRA)。我们的 ATR-SEIRA 平台对于在没有环境干扰的情况下进行原位和无标记的生物分子相互作用的监测非常有效和简单，允许在复杂的生物事件中提取即时的光谱信息。利用石墨烯等离子体的近场增强，我们以 L-选择素与其适体的结合相互作用为例进行了研究，以评估特定蛋白质识别过程。目标蛋白质的检测限达到 0.5 nM。我们的工作表明，化学掺杂的石墨烯等离子体与 ATR-SEIRA 相结合，是用于原位水相生物传感的有前途的信号增强平台。
