150 w xenon lamp

Fourier transform infrared
spectroscopy (FTIR) was conducted using a JASCO FTIR 4100 spectrometer,
with powder samples placed in the sample holder. UV–visible
optical absorption was performed using a JASCO V-650 spectrophotometer.
PL and PL excitation (PLE) spectra were recorded using a NanoLog Horiba
Jovin Yvon spectrofluorometer with an InGaAs detector for NIR (Hamamatsu
Photonics Co., Ltd, Japan). The X-ray diffraction pattern was recorded
with a Rigaku Smart lab X-ray diffractometer. High-resolution transmission
electron microscopy (HR-TEM) was accomplished using a JEOL JEM 2010,
operating at an acceleration voltage of 200 kV.^{25 (link)} Samples for HR-TEM analysis were drop-cast from the dilute
dispersions of SiQD-OD and SiQD-OD-P in toluene and water, respectively,
on ultrathin carbon (<10 nm thickness)-coated copper grid. Absolute
PL quantum yield was measured using a C9920-03G system, equipped with
a 150 W xenon lamp produced by Hamamatsu Photonics Co., Ltd., Japan.
Dilute solutions having absorption in between 0.1 and 0.2 were inserted
into the instrument with a 1 cm² quartz cuvette.^{26 (link)}

Absorption measurements were carried out on a Shimadzu UV-1650 PC spectrometer (Kyoto, Japan) in 1 cm quartz cuvette from 200 to 900 nm. Fluorescence spectra were obtained using a Hitachi F-7000 spectrometer (Tokyo, Japan). Solutions of a concentration of 10 µM were used for both absorption and fluorescence measurements at room temperature (∼25 °C). Absolute quantum yield measurements were carried out using an absolute photoluminescence (PL) quantum yield measurement system (C11347, Hamamatsu Photonics, Hamamatsu, Japan) equipped with a 150-W xenon lamp (Hamamatsu Photonics, Hamamatsu, Japan). All compounds were characterized by ¹H-NMR spectroscopy on a Bruker AM 250 spectrometer (Billerica, MA, USA). The purity of the products was checked by thin-layer chromatography (TLC, silica gel 60 mesh). The silica nanoparticles were detached by Eppendorf Centrifuge Model 5804. The size and morphology of silica nanoparticles were analyzed by using transmission electron microscopy (TEM) (JEOL, MA, USA). We used machine JEOL-JEM 2100F (Peabody, MA, USA) at an accelerating voltage of 200 kV. To prepare TEM samples, 0.001 wt.% solutions of silica nanoparticles were dropping onto holey carbon film copper. The solvent then was evaporated at room temperature.

All stopped flow experiments were performed on a KinTek SF-300X instrument (dead time of 1.3 ms) with a circulating water bath set to 4 °C. A 150-W Xenon lamp (Hamamatsu) was used as the light source. Samples were excited at 295 nm, and emission was monitored at 445 nm using a filter with a 45-nm band pass (Semrock). All stopped-flow data shown in the main text are an average of at least eight individual traces, and all stopped flow experiments were reproduced at least three times to ensure reproducibility. The TMX titration module for the SF-300X (KinTek Corp) was used for equilibrium titration experiments. Titrations were performed with 280 μl of a solution of enzyme and DNA_dd in the cuvette and 20.5 μl of dATP titrant added from a Hamilton syringe over the course of 5 min. The reaction was mixed by constant stirring from a micro-stir bar in the cuvette and the titration data were corrected for the small dilution before fitting in the KinTek Explorer. The titration experiment was performed on three separate occasions to ensure reproducibility.

The QYs of the thin reference films composed of R6G embedded within a PMMA matrix were determined using a commercial QY spectrometer (Quantaurus-QY, Hamamatsu Photonics, Hamamatsu City, Japan) or a lab-made QY measurement system consisting of an integrating sphere (819C-SL-3.3, Newport, Irvine, CA, USA) and a spectrometer equipped with a cooled charge-coupled device (CCD, Acton, MA, USA). The excitation light source was a 150-W Xenon lamp (Hamamatsu Photonics, Hamamatsu City, Japan) with a selectable wavelength or 514 nm laser line, respectively. For the confocal PL and transmission spectroscopy measurements, a lab-made laser confocal microscope combined with a spectrometer was used [15 (link),34 (link),35 (link),36 (link)]. The laser light was focused using a 0.9-NA objective lens, and the scattered light was collected using the same objective lens and guided to a 50-cm-long monochromator equipped with a cooled CCD. The excitation laser was a 514-nm-wavelength argon laser line, which was used for the PL measurements. Scanning electron microscopy (SEM, JEM-2100F, JEOL Corp. Tokyo, Japan) with field voltages of 5–20 KeV was used to obtain images of the cross sections of the thin R6G films embedded within a PMMA matrix, as well as to determine the thicknesses of these films.