Boosting the Quantum Yield of Oxygen-Doped g-C₃N₄ via a Metal–Azolate Framework-Enhanced Electron-Donating Strategy for Highly Sensitive Sulfadimethoxine Tracing

Abstract

Two of the most persistent challenges for the sensing applications of luminescent carbon nitride-based materials are poor quantum yields and aggregation-induced luminescence quenching in aqueous environments. Herein, a highly emissive oxygen-doped carbon nitride composite (OCNP@M7) was synthesized, with a metal−azolate framework (MAF-7) serving as a luminous booster. Both experimental studies and theoretical calculations suggest that the MAF-enhanced electron-donating effect dramatically promoted the electron density on the πstructure of oxygen-doped carbon nitride. In addition, the structural rigidity of MAF-7 effectively inhibits both aggregation and nonradiative energy dissipation. Consequently, OCNP@M7 exhibits strong and stable blue emission under UV light irradiation and an absolute quantum yield up to 95.2%, which is, as far as we know, the highest value among fluorescent carbon nitride materials in solution ever reported. OCNP@M7 could further function as a high-efficiency fluorescent probe for the sensitive detection of sulfadimethoxine residues in complex environments. It is anticipated that this strategy can be extended to fabricate various carbon nitride-based antibiotic monitoring systems with tailor-made functions.

Spatially Segregated MOF Bioreactor Enables Versatile Modular Glycoenzyme Assembly for Hierarchical Glycan Library Construction

“…A molecular docking study concerning enzyme to substrate binding energy was conducted to further verify the critical role of ZIF-90 in the catalysis. Considering the complexity of the entire structure of the frameworks, we proposed a simplified ZIF-90 model, imidazole-2-carboxylaldehyde monomer (Figures S9–13), to simulate the composite as previously reported . The hydroxyl group of anomeric carbon atom (C1-OH) of acceptor substrate GlcNAc was first deprotonated by the amino acid residues Asp208 and Asp228 of NahK to attack the γ-P atom of ATP to afford GlcNAc-1-P.…”

“…Considering the complexity of the entire structure of the frameworks, we proposed a simplified ZIF-90 model, imidazole-2-carboxylaldehyde monomer (Figures S9−13), to simulate the composite as previously reported. 25 The hydroxyl group of anomeric carbon atom (C1-OH) of acceptor substrate GlcNAc was first deprotonated by the amino acid residues Asp208 and Asp228 of NahK to attack the γ-P atom of ATP to afford GlcNAc-1-P. The residues Thr82 and Lys25 of GlmU and the Mg 2+ can stabilize and precisely orient the negatively charged GlcNAc-1-P for the nucleotidyl-transfer reaction to obtain UDP-GlcNAc (Figure 4a).…”

One-pot encapsulation of lactate dehydrogenase and Fe3O4 nanoparticles into a metal–organic framework: A novel magnetic recyclable biocatalyst for the synthesis of D-phenyllactic acid

“…The FT-IR bands corresponding to the different functional groups of MAF-7, MNPs@MAF-7, and LDH/MNPs@MAF-7 are indicated in Figure 3 . In the FT-IR spectrum of MAF-7, the strong peaks around 424, 1,640 and 2,930 cm −1 could correspond to the stretching vibrations of Zn-N, C-N, and imidazole C-H, respectively ( Tian et al, 2020 ; Wang Q. et al, 2022 ). Several bands were observed in the broad region of 2,500–3,500 cm −1 , which corresponded to the stretching vibrations of N-H, O-H, and C-H.…”

Band Structure Engineering Induced Ultraviolet–Visible Emission Bulk Carbon Nitride with Near‐Unity Quantum Yield for Information Security

“…Melem is a monoclinic molecular crystal based on tri-s-triazine (C 6 N 7 ) rings. The molecules of Phosphorus-doped g-C 3 N 4 quantum dots Solution:>90% Bulk: not reported 1) Solid-state reaction 2) Ultrasonic treatments 3) Hydrothermal reaction [7] Oxygen-doped g-C 3 N 4 nanoplates Solution: 95.2% Bulk: not reported 1) Hydrothermal reaction 2) Solid-state reaction 3) Acidification treatments [8] N-doped carbon dots Solution: 81% Bulk: not applicable Hydrothermal reaction [13] S-doped silicon quantum dots Solution: ≈66% Bulk: not applicable Hydrothermal reaction [14] Melem connect with each other via hydrogen bonds, forming two differently oriented layers stacking along the [10-1] direction. [11] For each Melem molecule, there exist three types of nitrogen, which can be marked as N(c), N(i), and N(t), corresponding to the corner nitrogen, inner nitrogen, and terminal nitrogen, respectively.…”

“…[ 7 ] Also, Xu and co‐workers promoted the electron density on the π‐structure of carbon nitride and successfully improved the PL efficiency of oxygen‐doped carbon nitride from 20.1% to 95.2% in solution via enhanced electron‐donating effect. [ 8 ] However, though great improvements have been achieved, the improvements were only made on the PL behaviors of carbon nitride materials (CNM) in solutions. The PL efficiency of bulk carbon nitride is still very limited.…”