The identification of biomolecules in aqueous solution by Fourier transform infrared spectroscopy provides an in-situ, real-time, non-destructive method for exploring the structure, reaction and transfer process of bioactive molecules. However, the strong absorption of the infrared spectrum of the aqueous solution masks the respective vibrational fingerprints of the biomolecules, which makes the application of this method challenging. The researchers of the National Nano Center and Zeyou Science and Technology jointly developed a microfluidic system for in-situ liquid environment Fourier transform infrared spectroscopy (FTIR) transmission mode testing. By constructing graphene nanostructures that can be effectively electrically regulated in physiological environments, they not only effectively stimulate the tunable response of graphene plasmons, but also successfully suppress the background signal interference in the water environment, it also effectively amplifies the infrared signal of the protein molecule. In addition, the researchers also used the isotope effect to monitor the hydrogen and deuterium proton exchange process of the monolayer protein film in the aqueous solution. This controllable graphene plasmon enhanced FTIR method can provide a new platform for the study of biological processes in aqueous solution at the nanoscale. The research results of

were published in ADVANCED MATERIALS on the topic of "Ultrasensitive Mid-Infrared Biosensing in Aqueous Solutions with Graphene Plasmons". Wu Chenchen, doctoral student of the National Nanoscience Center, was the author of the article, and researchers Yang Xiaoxia and Dai Qing were the co-corresponding authors.

Original Link: https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.202110525

Figure Experimental Method

Anhui Zeyou Technology Co., Ltd. is entrusted by researchers of the National Nanoscience Center to provide customized development support in the development and manufacture of in-situ Fourier transform infrared spectroscopy test-circulating liquid phase sample cell, the device is well compatible with commercial Fourier transform infrared spectroscopy test instruments, and has a convenient detachable feature, which has been greatly recognized by researchers.

in-situ infrared spectroscopy device physical

tunable graphene plasmon enhanced infrared spectroscopy platform (a) schematic diagram of experimental device (B) protein solution with (red spectral line)/without (blue spectral line) in microfluidic system) Graphene plasmon-enhanced infrared spectrum (collected in transmission mode)(c) Graphene plasmon-enhanced infrared spectrum eliminates the influence of water, direct identification of amide I bands of nanoproteins in aqueous solution.

Figure Graphene Isoplasmon Enhanced Infrared Spectroscopy In-situ Detection of Hydrogen and Deuterium Proton Exchange Process of Nano-protein (A) Graphene Enhanced Infrared Spectroscopy of Amide I Band and Amide II Band of Nano-protein in Different Circulation Solution Environments (Water and Heavy Water) (B) Schematic Diagram of Hydrogen and Deuterium Proton Exchange Process of Protein (C) vibrational fingerprint changes of proteins in different concentrations of heavy water environment were detected by plasmon enhanced infrared spectroscopy.