Plasmon-Enhanced Peroxidase-like Activity of Nitrogen-Doped Graphdiyne Oxide Quantum Dots/Gold–Silver Nanocage Heterostructures for Antimicrobial Applications

Abstract

Plasmon stimulation is an intriguing method to modulate the enzyme-mimic functions of nanomaterials, while utilization of plasmon excitation remains of low efficiency. Herein, by loading nitrogen-doped graphdiyne quantum dots (N-GDQDs) onto gold–silver nanocages (AuAg NCs), hollow cube-shaped N-GDQDs/AuAg NC heterostructures with strong local surface plasmon resonance (LSPR) response in the near-infrared (NIR) region are reported. This nanozyme can concurrently harvest LSPR-induced hot carriers and produce photothermal effects, resulting in a significantly enhanced peroxidase-like activity upon 808 nm irradiation. Both experimental data and theoretical calculations reveal that the remarkable catalytic performance of N-GDQDs/AuAg NCs results from the narrow band gap semiconductor characteristics of N-GDQDs, LSPR effect of AuAg NCs, and fast interfacial electron transfer dynamics. Moreover, this nanozyme is demonstrated to achieve >99.999% antibacterial efficiency against methicillin-resistant Staphylococcus aureus (MRSA), S. aureus, and Escherichia coli in 10 min in vitro and in vivo. This study not only sheds light on the mechanism of the nanozyme/photocatalysis coupling process but also provides a new avenue for rationally designing plasmonic metal/semiconductor-involved nanozymes for synergistic photothermal and photoenhanced nanozyme therapy.

Efficient nanozyme engineering for antibacterial therapy

“…To date, with the rapid development of nanotechnology, a large number of antibacterial nanozymes have been developed, from noble-metal (e.g. Au [19][20][21][22][23][24][25][26], Pt [27], Cu [28], Ir [29], Ag [30], Au-Pt [31,32], Pd-Cu [33], Pd-Pt [34], Au-Ag [35], etc), transition metal oxide or sulfide (e.g. Fe 3 O 4 [36][37][38], CuO [39], CeO 2 [40], V 2 O 5 [41], Co-V mixed metal oxide (MMO) [42], MoS 2 [43][44][45][46][47], NiS 2 [48], CuS [49][50][51][52], Co 4 S 3 [53], MnO 2 [54] etc), and nanocarbon (e.g.…”

“…Actually, for NIR responsive metal-semiconductor hybrid nanozymes, the NIR excitation can not only induce local photothermal effect but also transfer of hot electrons simultaneously, of which the enzyme-like function is dominantly dependent on the hot electrons' transfer. Taking the gold-silver nanocages loaded nitrogen-doped graphdiyne quantum dots (N-GDQDs/AuAg NC) heterostructures as an example [35], as shown in figure 3(D), under NIR excitation, the N-GDQDs was induced to produce heat and hot carriers (e − ), which was then injected into AuAg, remarkably accelerating the decomposition of H 2 O 2 into •OH. Taking advantage of NIR-enhanced POD-like activity, the N-GDQDs/AuAg NC nanozyme possessed efficient broad-spectrum antibacterial activity under NIR irradiation.…”

Graphdiyne Oxide Quantum Dots: The Enhancement of Peroxidase-like Activity and Their Applications in Sensing H2O2 and Cysteine

“…For instance, hemin has been chosen as a functional molecule to improve peroxidase-like activity. − Nanoparticles are also a good choice, such as Pd, PdFe, CeO 2 , and CuS . It has been reported that heteroatoms (N, B, and S) can enhance the enzymatic activity. − Although great efforts have been made to improve the enzymatic activity and the application performance of GDY-based nanozymes, the understanding of their intrinsic properties or their enzyme-mimicking behavior is still limited.…”

“…GDY-based quantum dots have attracted great attention due to the size effect. − Since decreasing the size of carbon nanozymes is also an important way to improve the catalytic performance, ,− graphdiyne oxide quantum dots (GDYO QDs) with lateral sizes less than 100 nm were prepared through an oxidative cleavage method using concentrated HNO 3 in this work. The peroxidase-like activity of graphdiyne was greatly enhanced, which has not been explored yet.…”

Surface-Plasmon-Mediated Alloying for Monodisperse Au–Ag Alloy Nanoparticles in Liquid

“…Noble-metal nanoparticles (Ag, Au, etc.) have strong interactions with electromagnetic radiation, leading to the excitation of localized surface-plasmon resonance (LSPR) . LSPR have limited lifetimes and decay by radiatively emitting photons or nonradiatively generating electron–hole pairs. − Recently, a considerable amount of work has been carried out on the hot carriers generated by LSPR’s nonradiative decay.…”