Ntegra spectra system

The X-Ray photoelectron spectrometer (XPS, ULVAC-PHI) was carried out to investigate the bonding environment and chemical component. The structure characteristic of GDY was analyzed by using Raman spectra (NT-MDT NTEGRA Spectra System). Morphological information was measured using scanning electron microscope (Hitachi S-4800 FESEM). Magnetic moment measurements were recorded using a vibrating sample magnetometer (PPMS-VSM, Quantum Design) with temperature changing from 2 K to 300 K.

AFM analysis was conducted using the NTEGRA Spectra system (NT-MDT; Santa Clara, CA, USA). Diluted solutions were allowed to down for 30 s spin coating at 400× g. GA^P and GA^P × CO^P protein sample solutions were applied to a freshly cleaved mica surface. To prepare GA^P and GA^P × CO^P samples on the functionalized substrate, the surface was ultrasonically washed with ethanol for approximately 1–3 min. to remove surface impurities. Treatment solution was applied to the mica surface and incubated for 15 min. at RT. The droplet was removed from the surface with nitrogen, and the surface was rinsed with water. The samples were analyzed using AFM. All of the measurements were conducted in air under ambient conditions.

The preparation for surface-enhanced Raman spectroscopy (SERS) measurement was performed by immersing arrays of in-plane shape-different Ag nanoparticles into Rhodamine 6 G aqueous solutions with a concentration of 10^-6M. The immersion procedure was carried out for 4 h to assure that sufficient R6G molecules can be chemisorbed on the surface of Ag nanoparticles, especially the hot spots under electromagnetic excitation (namely, the vertices of triangular nanoparticles). Before measurement, all samples were dipped into DI water for 30 s and dried with nitrogen flow. SERS signals spectra with three main peaks at 1363, 1508, and 1650 cm⁻¹ were collected by the NTEGRA Spectra system (NTMDT) equipped with a laser source of 532-nm wavelength. The measured data were treated with baseline correction to extract SERS spectra from the broad background.