Mei Yihong,Zhong Changyin,Li Ling,Nong Jinpeng,Wei Wei,Hu Weihua
Surface plasmon resonance (SPR) employs a gold (Au) thin film (ca. 50 nm in thickness) chip to generate a surface plasmonic wave (SPW) for in situ monitoring of the interface/surface, which makes it intrinsically compatible with electrochemistry for combined electrochemical surface plasmon resonance (EC-SPR) investigations. However, conventional SPR Au chips suffers from a high background signal, narrow electrochemical window, and limited electrochemical stability. Presented in this work is a novel SPR chip composed of the Au/long-chain alkane thiol self-assembled monolayer/single-layer graphene (Au/SAM/G) sandwich architecture to address these problems. On this chip, the single-layer graphene serves as a working electrode for electrochemical measurement, and the underlying Au film serves as the SPW support for SPR monitoring; the sandwiched thiol monolayer enables the electrical separation of the graphene and Au film to protect the Au film from electrochemical polarization. Our experiment indicates that the electrochemical window of such a chip extends beyond the hydrogen/oxygen evolution reaction potential on Au with significantly improved electrochemical stability and suppressed background signal. Moreover, its intrinsic SPR sensitivity is completely reserved even compared to that of the conventional SPR Au chip. This Au/SAM/G chip may offer a valuable solution to the EC-SPR investigations in harsh conditions.
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Peipei Wang,Tian Liu,Yena Liu,Jing Tian,Xinyu Zhang,Jiaqi Guo,Yongcan Jin,Huining Xiao,Junlong Song
It is a challenge to interpret the signals obtained by Quartz Crystal Microbalance (QCM) and Surface Plasmon Resonance (SPR) accompanied with in the significant changes of the density and/or refractivity of media. The work presented herein focuses on demonstrating a universal in-situ and real-time monitoring methodology for ultrathin film formation on gold chips in varied media. Biomimetic model cellulase/enzyme film was immobilized in-situ on gold surface of sensors, followed by revealing its interaction with lignosulphonate in the media changed from ethanol-based to aqueous ones. Combining the techniques of Quartz Crystal Microbalance with Dissipation monitoring (QCM-D) and Multi-parametric Surface Plasmon Resonance (MP-SPR) along with respective software and models enabled us to precisely characterize the thickness, viscous and shear elastic moduli, and the coupled solvent for individual layer formed over the entire process, which are unachievable with conventional methods. The methodology provides real-time monitoring of filming process and offers us an in-situ qualify control approach to the biomimetic model films formed on different substrates including gold chip.
危险品化学品经营许可证（带存储）