Plasmaquad 3

AgPd_0.38 was impregnated onto silicone catheters through a protocol as described above in “Modifying a surface with AgPd_0.38” section. Briefly, a sterile silicone catheter (inner diameter = 2.2 mm, outer diameter = 3.4 mm) was cut into sections of 4.5 cm in length. The silicone catheters (n = 8) were added into a beaker, followed by successive additions of Millipore water (149 mL), dopamine hydrochloride (300 mg), and Tris-HCl buffer (1.5 M Tris-HCl at pH = 8.8, 1 mL) and then gentle stirring (200 rpm) at ~15 °C for 24 h. The as-treated silicone catheters were subsequently taken out, washed with Millipore water once, and then dried at 37 °C for 4 h, which yielded the polydopamine (PDA)-coated catheters (Ca/PDA). A resulting Ca/PDA catheter was then immersed into a AgPd_0.38 dispersion (0.2 mg/mL, 1 mL, pH = 3.6), followed by gentle vibration (~100 rpm) for 48 h. The as-treated catheter was subsequently taken out, washed with Millipore water once, and then dried at 37 °C for 4 h, which yielded the expected AgPd_0.38-coated catheter, Ca/PDA/AgPd.
To determine the amount of AgPd_0.38 impregnated onto a PDMS/PDA wafer, we added a Ca/PDA/AgPd catheter into aqua regia (1 mL), and the resulting solution was then measured with a Thermo Scientific PlasmaQuad 3 inductively coupled plasma mass spectrometry (ICP-MS) to quantify the amount of Pd and Ag therein.

SEM and EDS images were taken on a JEOL JSM-6490 field emission scanning electron microscope operated at 5 kV with EDS detector. Transmission electron microscope (TEM), high-resolution TEM (HRTEM), and selected area electron diffraction (SAED) images were collected on a JEOL JEM-2100F field-emission high-resolution transmission electron microscope operated at 200 kV. The samples were prepared through ion-milling at the temperature of 223 K. 3D atomic-probe tomography (APT) characterizations were performed in a CAMEACA LEAP 5000 XR local electrode atom probe. The specimens were analyzed at 45 K in laser mode at a laser energy of 100 pJ, pulse rate of 200 kHz, and detection rate of 0.5%. Imago Visualization and Analysis Software (IVAS) version 3.8 was used for creating the 3D reconstructions and conducting the data analysis. X-ray diffraction (XRD) patterns were recorded by using a Rigaku SmartLab X-ray diffractometer with Cu-Kα radiation (λ = 1.5418 Å). The loading mass of samples on CC were measured with a Thermo Scientific Plasma Quad 3 inductively coupled plasma mass spectrometry (ICP-MS) after dissolving the samples with aqua regia solution. Each sample was measured for three times to minimize the error. XPS spectra were collected on a Thermo Scientific Escalab 250Xi X-ray photoelectron spectrometer, using non-monochromatized Al-Kα X-ray (1486.6 eV) as the excitation source.

Transmission electron microscopy (TEM) images were taken on a Hitachi Model H-7700 microscopy at an accelerating voltage of 100 kV. High-resolution transmission electron microscopy images and energy dispersive spectroscopy mapping profiles were recorded on a JEOL ARM-200F field-emission transmission electron microscope at an accelerating voltage of 200 kV. Powder XRD patterns were collected using a Japan Rigaku DMax-γA rotating anode X-ray diffractometer equipped with diffracted beam graphite monochromator (Cu Kα radiation (λ = 1.54178 Å)). The concentrations of various elements in the prepared samples were measured with a Thermo Scientific PlasmaQuad 3 inductively-coupled plasma mass spectrometry (ICP-MS) after dissolving them with a mixture of HCl and HNO₃ (3:1, volume ratio). Ultraviolet-visible (UV-Vis) extinction spectra were recorded in the spectral region of 300–1000 nm with an Agilent Technologies Cary 60 spectrometer. The samples were diluted with deionized water to the same concentration before being measured in a quartz cuvette.