Cary 300 uv vis spectrometer

CYP-mediated
NADPH oxidation was
measured using kinetics mode in a Cary 300 UV–vis spectrometer
(Agilent Technologies). 0.2 μM (final concentration) of CYP
was taken in 0.1 M potassium phosphate buffer (pH 7.4) and incubated
with 0.6 μM (final concentration) of CPR for 5 min with a reaction
volume of 400 μL. The reaction was initiated with 200 μM
of NADPH, and the absorption change was monitored over 10 min at 340
nm. The rate of NADPH consumption (or NADPH to NADP⁺ conversion)
was calculated by taking the molar extinction coefficient as 6.22
mM^–1 cm^–1 at 340 nm. To estimate
the change in NADPH oxidation in the presence of CBC, both CYP and
CPR were further incubated using CBC (final concentration 50 μM)
for 5 min followed by measuring the change in absorbance at 340 nm
as discussed earlier.

Steady-state ultraviolet–visible (UV–Vis) absorption spectra were recorded using a Cary 300 UV–Vis spectrometer (Agilent Technologies), equipped with a Versa20 Peltier-based temperature-controlled cuvette chamber (Quantum Northwest), and fluorescence data were recorded using a LPS 220 spectrofluorometer (PTI, Monmouth Junction, NJ, USA), equipped with a TLC50TM Legacy/PTI Peltier-based temperature-controlled cuvette chamber (Quantum Northwest).
Thermodynamic dissociation constants for NFAST:CFASTn (n = 8–11) couples were determined using peptides synthesized for CFASTn (n = 8–11) and recombinantly purified NFAST. The affinity for NFAST:CFAST11 in the presence of 10 µM HMBR was determined independently from a minimum of three different purifications of NFAST. NFAST:CFAST11 was then run in parallel as an internal control for the determination of the other NFAST-CFAST combinations, which were all performed on the same day with the same preparation of NFAST. Thermodynamic dissociation constants were determined with a Spark 10M plate reader (Tecan) and fit in Prism 6 to a one-site-specific binding model.

The electrical characteristics and photodetector performance were measured by semiconductor parameter analyzer (Keysight 2912) in ambient conditions. The surface morphology of MXene and AgNWs was measured by AFM (Bruker MultiMode 8). The SEM images of MXene were obtained on a focusion beam/SEM (Nova NanoSEM 230). The TEM was performed with a JEOL JEM-2100 microscope operated at 200 kV. The HRTEM images were acquired by a Gatan CCD camera operated in electron-counting mode. The UV–vis absorption spectra for films were tested on quartz substrates with Cary 300 UV–vis spectrometer (AgilentTechnologies). The UPS and XPS were conducted at constant analyzer energy model with energy step size of 0.02 and 0.1 eV, respectively (Thermo Scientific ESCALAB 250). The monochromatic light was produced by a 300 W wavelength-adjustable xenon lamp source (Beijing NBET Technology Co., Ltd., Omno302).

Lidocaine hydrochloride monohydrate (LiHCl) and theophylline (Thp) were selected as the representative substances, which are commonly employed for evaluating the drug delivery efficiency of different porous materials [25 (link),33 (link),34 (link)]. LiHCl is a type of amide-class local anaesthetics that is used to relieve nerve pain. Thp is a xanthine derivative, which is commonly used for asthma treatment. Thp molecules are immediately absorbed after oral administration, which relaxes the pulmonary blood vessels and the smooth muscles of bronchial airways and reduces the responsiveness of the airway to allergy-stimulating chemicals. Their solubilities in water, the concentrations used in the present study, and their indicative wavelengths in the UV-Vis spectrometer are listed in Table 2.
For each drug, a concentration measurement was carried out to correlate the absorption value with the solution concentration using the Cary 300 UV-Vis spectrometer (Agilent Technologies, Santa Clara, CA, USA). Four concentrations of drug solutions were prepared with 0.1 N HCl and the absorption values were recorded. The standard concentration curves of LiHCl and Thp are shown in Figures S1 and S2.

The rate of NADPH (ε = 6.2 108 mM⁻¹·cm⁻¹ at A_340nm) consumption by each CYP2C8 variant (0.2 μM) incubated with CPR (0.6 μM) and PAC (70 μM) in 0.1 M potassium phosphate buffer and 200 μM NADPH was determined via UV–vis spectroscopy using a Cary 300 UV–vis spectrometer in kinetics mode (Agilent Technologies), as previously described [41 (link),44 (link)].

UV–Visible spectra
were obtained on an Agilent Technologies Cary 300 UV–vis spectrometer.
NMR spectroscopy was carried out at 25 °C on a Bruker 500 MHz
spectrometer equipped with a Prodigy cold probe (¹H, ¹³C, ¹H–¹³C multiplicity edited
HSQC, ¹H–¹H COSY, ¹³C–¹³C COSY, ¹H–¹³C HMBC, ¹H–¹⁵N HMBC, ¹³C INADEQUATE, and TOCSY)
or on a Varian Inova 600 MHz spectrometer equipped with a ¹H, ¹³C, ¹⁵N triple resonance inverse detection
probe (¹H with or without ¹³C, ¹⁵N, or ¹³C/¹⁵N decoupling, and ¹H–¹⁵N HMBC with or without ¹³C decoupling). Spectra
were collected in DMSO-d₆ or D₂O. Spectra were
indirectly referenced by the residual solvent peak or ²H lock. MS analysis was carried out on a Waters Xevo G2-XS QTof with
positive mode electrospray ionization coupled to an AQUITY UPLC H-Class
system with a Waters BEH C18 column. Gbt samples were run with a linear
gradient of 0 to 100% acetonitrile (0.1% formic acid) in ddH₂O (0.1% formic acid) over 10 min. Deionized water was dispensed from
a Milli-Q IQ 7000 water purification system (Resistivity 18.2 MΩ).
All glassware was acid-washed with 4 M HCl and subsequently rinsed
with Milli-Q water.

UV–visible spectra
were obtained on an Agilent Technologies Cary 300 UV–vis spectrometer.
NMR spectroscopy was carried out at 25 °C on a Bruker 500 MHz
spectrometer equipped with a Prodigy cold probe (¹H, ¹³C, ¹H–¹³C multiplicity edited
HSQC, ¹H–¹H COSY, ¹H–¹³C HMBC, ¹H–¹⁵N HMBC, ¹H–¹⁵N HSQC, TOCSY, NOESY). NMR spectra for characterization
were collected in DMSO-d₆, and spectra
of the photoproduct were collected in 50 mM Na₂HPO₄-buffered D₂O (pD 8.0). Spectra were indirectly
referenced by the residual solvent peak or ²H lock. MS
analysis was carried out on a Waters Xevo G2-XS QTOF with positive
mode electrospray ionization coupled to an AQUITY UPLC-H-Class system
with a Waters BEH C18 column. Samples were run with a linear gradient
of 0% to 100% acetonitrile (0.1% formic acid) in ddH₂O
(0.1% formic acid) over 10 min. IR data were collected on a Bruker
Alpha FTIR spectrophotometer. CD data were collected on a JASCO J-1500
CD spectrometer on tistrellabactin A (71 μM) and tistrellabactin
B (52 μM) in Na₂HPO₄ (pH 8). CD data was
referenced to the buffer and collected with a scan rate of 20 nm/min,
DIT 8 s bandwidth of 1 nm, and data pitch of 0.5 nm. Deionized water
was dispensed from a Milli-Q IQ 7000 water purification system (Resistivity
18.2 MΩ). All glassware was acid-washed with 4 M HCl and subsequently
rinsed with Milli-Q water.