Au-Cu@PANI Alloy Core Shells for Aerobic Fibrin Degradation under Visible Light Exposure

Abstract

Fibrin plays a critical role in wound healing and hemostasis, yet it is also the main case of cardiovascular diseases and thrombosis. Here, we show the unique design of Au-Cu@PANI alloy core–shell rods for fibrin clot degradation. Microscopic (transmission electron microscopy (TEM), scanning transmission electron microscopy–energy-dispersive X-ray (STEM-EDX)) and structural characterizations (powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS)) of the Au-Cu@PANI hybrid material reveal the formation of Au–Cu heterogeneous alloy core rods (aspect ratio = 3.7) with thin Cu2O and PANI shells that create a positive surface charge (ζ-potential = +22 mV). This architecture is supported by the survey XPS spectrum showing the presence of Cu 2p, N 1s, and C 1s features with binding energies of 934.8, 399.7, and 284.8 eV, respectively. Upon photolysis (λ ≥ 495 or 590 nm), these hybrid composite nanorods provide sufficient excited-state redox potential to generate reactive oxygen species (ROS) for degradation of model fibrin clots within 5–7 h. Detailed scanning electron microscopy (SEM) analysis of the fibrin network shows significant morphology modification including formation of large voids and strand termini, indicating degradation of fibrin protofibril by Au-Cu@PANI. The dye 1,3-diphenylisobenzofuran (DPBF) used to detect the presence of 1O2 shows a 27% bleaching of the absorption at λ = 418 nm within 75 min of irradiation of an aqueous Au-Cu@PANI solution in air. Moreover, electron paramagnetic resonance (EPR) spin-trapping experiments reveal a hyperfine-coupled triplet signature at room temperature with intensities 1:1:1: and g-value = 2.0057, characteristic of the reaction between the spin probe 4-Oxo-TEMP and 1O2 during irradiation. Controlled 1O2 scavenging experiments by NaN3 show 82% reduction in the spin-trapped EPR signal area. Both DPBF bleaching and EPR spin trapping indicate that in situ generated 1O2 is responsible for fibrin strand scission. This unique nanomaterial function via use of ubiquitous oxygen as a reagent could open creative avenues for future in vivo biomedical applications to treat fibrin clot diseases.

Innovative Synthesis of PANI/Cu2O Nanocomposite and Its Antibacterial Properties**

“…[27] Compared with pure PANI, the absorption peak intensity of PANI/Cu 2 O in the ultraviolet region is significantly enhanced, and the absorption in the visible region is also enhanced to a certain extent. The absorption peak appears at 450 nm for PANI/Cu 2 O is identified as the character absorption of Cu + , [28] confirming the composite formation.…”

Novel porphyrin derivative containing cations as new photodynamic antimicrobial agent with high efficiency

“…The quantities of ROS generated from different PCT membranes under light exposure in natural light indoors and at room temperature were quanti-ed using 1,3-diphenylisobenzofuran (DPBF) as a chemical sensing agent. 30 The detection mechanism is based on the fact that the generated 1O 2 can irreversibly quench DPBF absorbance at 410 nm upon light irradiation. As shown in Fig.…”

A Photoelectrochemical Platform Based on Polyaniline-Modified Titanium Dioxide Facet Heterostructure

“…Introducing a carrier conduction medium between FHs should be an effective solution to settle the matter of charge recombination caused by carrier propagation between crystal interfaces. Polyaniline has become an excellent candidate for electronic media due to its easy preparation, reversible redox, environmental friendliness, and controllable conductivity. − In fact, it has been widely used in constructing PEC sensors. For example, Ju and co-workers applied polyaniline (PANI)/titanium dioxide (TiO 2 ) nanotube composite to lactic acid photoelectric detection and obtained higher photocatalytic activity.…”