Red Emissive Carbon Dot Superoxide Dismutase Nanozyme for Bioimaging and Ameliorating Acute Lung Injury

Abstract

Harnessing the physiochemical properties and enzymatic activities of nanozymes will provide new insights for disease theranostics. Herein, a novel carbon dot (C‐dot) superoxide dismutase (SOD) nanozyme that exhibits red fluorescence with emission wavelength of 683 nm and shows high SOD‐like activity of >4000 U mg−1 is reported, which presents the great potential for imaging the biodistribution of nanozyme itself in vivo and ameliorating acute lung injury. Through surface modifications, the mechanism of C‐dot SOD nanozyme activity is revealed to be relied on their surface functional groups which bind with superoxide radicals, promote the electron transfer between C‐dots and superoxide radicals, and finally accelerate the dismutation of superoxide radicals. The absolute quantum yield of ≈14% of red fluorescence C‐dot nanozyme endow it bioimaging in vitro and in vivo. Moreover, the C‐dot nanozyme effectively enters the cells, accumulates at mitochondria, and protects living cells from oxidative damage by scavenging reactive oxygen species (ROS) and reducing the levels of pro‐inflammatory factors. Importantly, in vivo animal experiments demonstrate the accumulation of C‐dots in injure lung and therapeutic effect of C‐dot nanozyme toward acute lung injury in mice. The red fluorescent C‐dot SOD nanozyme shows great potential for in vivo bioimaging and management of ROS‐related diseases.

Photoinduced Electron Transfer Modulated Photoelectric Signal: Toward an Organic Small Molecule-Based Photoelectrochemical Platform for Formaldehyde Detection

“…The high-resolution XPS spectra of Ti in NFC/TiO 2 (Figure g) exhibited binding energies at 464.1 and 458.4 eV, ascribed to Ti 2p 1/2 and Ti 2p 3/2 , respectively, and were in agreement with those observed in the TiO 2 sample . Notably, no apparent N 1s signal was detected in TiO 2 (Figure h), while an evident N 1s peak emerged upon NFC functionalization, which was deconvoluted into three peaks with binding energies at 400.2, 399.8, and 399.1 eV, corresponding to N–(C) 3 , N–H, and N–(H) 2 , respectively. − Additionally, the XPS spectra of O 1s (Figure i) contained four peaks: 531.8 and 529.6 eV were assigned to Ti–OH and Ti–O bonds in TiO 2 , while 533.7 and 531.2 eV corresponded to C–O and CO in the NFC molecule. , …”

“…Additionally, the corresponding atomic content of C and N increased (Table S1) compared with TiO 2 , which could be attributed to the successful binding of the NFC molecule. The high-resolution XPS spectra of Ti in NFC/TiO 2 (Figure 2g) exhibited binding energies at 464.1 and 458.4 eV, ascribed to Ti 2p 47,48 Figure S9 illustrates the absorption spectra of TiO 2 and NFC/TiO 2 . The incorporation of NFC did not alter the absorption spectrum of TiO 2 but instead generated a new absorption peak at approx.…”

Hypoxia mitigation by manganese-doped carbon dots for synergistic photodynamic therapy of oral squamous cell carcinoma

“…Previous studies have shown that a series of carbon nanomaterials possess inherent peroxidase activity ( Sun et al, 2015 ; Liu et al, 2023 ). CDs possess high enzymatic activity due to their small size, good biocompatibility, and tunable surface.…”

“…Previous studies have shown that a series of carbon nanomaterials possess inherent peroxidase activity (Sun et al, 2015;Liu et al, 2023).…”

Novel Dual-Emission Carbonized Polymer Dot-Based Ratiometric Fluorescence Probe for the Sensitive Detection of Tertiary Butylhydroquinone

“…Moreover, CDs possess excellent reactivity and unique photoluminescence properties because the nanoparticle surface is easily modified by various functional groups. When the analyte binds with the surface groups, distinct color and fluorescence changes are observed. , These virtues promote the diverse applications of CDs, including in biological imaging and chemical detection. , Depending on their composition and structure, CDs can be categorized into several types including graphene quantum dots (GQDs), graphitic carbon nitride quantum dots (CNQDs), carbon quantum dots (CQDs), carbon nanodots (CNDs), and carbonized polymer dots (CPDs) . CPDs are a new member of the CD family and possess a hybrid structure consisting of a carbon core and functional groups/polymer chains on the surface due to the low degree of carbonization during their preparation process .…”