F 7000 fluorescence spectrophotometer

All chemicals and reagents used in this work were AR grade 1 unless noticed and purchased from Sigma-Aldrich Chemical Corporation, including HAuCl₄, L-cysteine (L-Cys) and anhydrous FeCl₃. Other inorganic chemicals were purchased from Tianjin Chemical Corporation. Solvent water was purified and obtained from Millipore. All glassware was first treated with aqua regia at 40°C and then washed with purified water. XPS and DLS experiments were carried out by a PHI-5000 Versaprobe III X-ray photon–electron spectrophotometer (ULVCA-PHI, United States) and a Malvern Zetasizer Nano ZS90 laser particle size and zeta potential analyzer (Trek, Taiwan). IR spectra were recorded using a Bruker Vertex 70 FTIR spectrometer. The TEM image was obtained with a JEM-2010 transmission electron microscope (JEOL, Japan). UV-vis absorption spectra were obtained using a Shimadzu UV-3101PC spectrophotometer and a Biotek ELx800 automatic enzyme-linked immunosorbent assay. Emission spectra were recorded using a Hitachi F-7000 fluorescence spectrophotometer (Xe lamp). Emission quantum yield was determined by using this Hitachi F-7000 fluorescence spectrophotometer with the help of an integrating sphere. The reference was quinine sulfate (20 μM) in diluted H₂SO₄ (0.1 M). The emission lifetime was measured with a TEKTRONIX TDS-3052 oscilloscope (excited by an optical parametric oscillator).

The PL and PLE spectra were recorded at 1 nm intervals at RT using a F7000 fluorescence spectrophotometer (Hitachi High-Tech, Japan). For PL measurements, slits of 2.5 nm were used for both excitation and emission. The absolute quantum efficiencies, also known as QYs, of the glasses were measured using a Quantaurus-QY integrating sphere spectrometer (Hamamatsu Photonics, Japan). The error bars were ± 2. The emission decay was measured at RT using a Quantaurus-Tau system (Hamamatsu Photonics, Japan) with a 340 nm LED. The accumulated counts for evaluation were 50,000.

ThT fluorescence was recorded using F-7000 fluorescence spectrophotometer (Hitachi High-Technologies Corporation) with fluorescence excitation at 412 nm and emission at 485 nm. Protein solution was dissolved in 50 mM Tris-HCl pH 7.4, 150 mM NaCl buffer incubated for 2 h at 37 °C heat followed by 2 h at 25 °C. Readings were taken from samples after incubating 20 μM of induced and control protein solution with 20 μM of ThT for 15 min. Three independent measurements were performed and subsequently averaged for each sample.

The PL and PLE spectra were recorded at 1 nm intervals at RT using an F7000 fluorescence spectrophotometer (Hitachi High-Tech. Japan). Band pass filters of 2.5 nm for the PL measurement were used for both excitation and emission. The absorption spectra at RT were recorded at 1 nm intervals using a U3500 UV-vis-NIR spectrometer (Hitachi High-Tech. Japan). The absolute quantum efficiencies, also known as quantum yields (QYs), of the glasses were measured using an integrating sphere Quantaurus-QY (Hamamatsu Photonics, Japan). The error bars were ±2. The emission decay at RT was measured using a Quantaurus-Tau system (Hamamatsu Photonics, Japan) with a 340 nm LED. The accumulated counts for evaluation were 50,000. Scintillation (radioluminescence) spectra were measured by using a CCD-based spectrometer (Andor DU920P CCD and SR163 monochromator) under X-ray exposure^{23 (link)}. The supplied bias voltage and tube current were 40 kV and 0.52 ~ 5.2 mA, respectively.