Search

Various unique spatial structures are often found in the enzymes of biological systems. From the consideration of bionics, it is challenging but meaningful to design nanozymes with distinctive structures to enhance their bioactivities. To explore the relationship between the structure and activity of nanozymes, in this work, a special structural nanoreactor, namely small pore black TiO2 coated/doped large pore Fe3O4 (TiO2/–Fe3O4) loaded with lactate oxidase (LOD), was constructed for chemodynamic and photothermal synergistic therapy. Specifically, LOD loaded on the surface of the TiO2/–Fe3O4 nanozyme alleviates the low level of H2O2 in the tumour microenvironment (TME); the black TiO2 shell with multiple pinhole channels and a large specific surface area not only facilitates LOD loading, but also enhances the affinity of the nanozyme for H2O2; H2O2 is continuously enriched on the surface of the TiO2/–Fe3O4 nanozyme and transmitted to mesoporous Fe3O4, in turn efficiently producing abundant toxic hydroxyl radicals (˙OH) for chemodynamic therapy. Meanwhile, the TiO2/–Fe3O4 nanozyme under 1120 nm laser irradiation has excellent photothermal conversion efficiency (η = 41.9%), and further accelerates the production of ˙OH for amplifying the chemodynamic therapy efficiency. This self-cascading, special structure nanozyme provides a novel strategy for application in highly efficient tumour synergetic therapy. [ABSTRACT FROM AUTHOR]

Surface assisted laser desorption ionization mass spectrometry (SALDI‐MS) is a powerful analytical technology for the high‐throughput detection of metabolites, drugs, and other bioactive molecules. The performance of SALDI‐MS in enhancing molecules desorption and ionization mainly depends on the surface properties of matrix utilized. Here, black titanium dioxide (B‐TiO2) nanoparticle is used for the first time as a novel matrix for enhancing laser desorption and ionization (LDI) and demonstrates significant advantages over white titanium dioxide (W‐TiO2). Further, the black mesoporous TiO2 coated Fe3O4 magnetic nanoparticles (B‐mTiO2 MNPs) are designed and prepared, which possess a high molar absorption coefficient, strong magnetic response, higher specific surface area, and ample phosphorylation binding sites. The B‐mTiO2 MNPs exhibit a superior ionization efficiency, low background signal, and good reproducibility (RSD < 10%) in the analysis of compounds with different molecular weights and practical bio‐sample. Salt tolerance of B‐mTiO2 MNPs up to 10 mm PBS, meanwhile, B‐mTiO2 MNPs also provides excellent enrichment efficiency for phosphopeptides (the detection limit low to 5 × 10−10 M). [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride (g-C3N4) is recognized as a favorable substrate for monoatom catalysts due to its uniform nanoholes for anchoring metal monoatoms, while the oxygen evolution reaction (OER) overpotential (ηOER) values of g-C3N4-based metal monoatom catalysts are still large. To reduce the ηOER values, a class of novel TM1NM1NM1/g-C3N4 was designed via density functional theory simulations, where TM1 = Fe1, Co1 or Ni1 and NM1 = C1, N1 or O1. Contributing by two extra-NM1 atoms, the OER catalytic activities of these materials were effectively improved owing to the shortened TM1–NM bonds and weakened chemical activity of TM1 atoms. Based on the volcano activity relationship between the theoretical overpotential (ηOER) and d band center of the TM1 atom (εd), the chemical activity of TM1 atoms needs to be adjusted to a suitable magnitude (εd near −4.883 eV) for a good catalytic activity. The designed Fe1C1O1/g-C3N4 with the εd of −4.893 eV exhibited an excellent OER catalytic activity of ηOER = 0.219 V. This strategy was applied to devise the reaction active sites and highly efficient catalysts by adjusting the chemical activity of the TM1 atom with suitable extra-NM1 atoms. [ABSTRACT FROM AUTHOR]

Electrospray is a widely recognized physical process and has various applications, such as in electrospinning, space propulsion, and mass spectrometry (MS). Particularly, electrospray emitters are integral to the exceptional performance of electrospray ionization mass spectrometry (ESI-MS). This study introduced a novel method for fabricating electrospray emitters using two-photon direct laser writing, resulting in the printing of nanosprayer arrays directly onto capillary tips. Utilizing a novel acrylic polyhedral oligomeric silsesquioxane photoresist, a multinozzle sprayer with micrometer scale channels was designed and printed on a capillary that is compatible with both frontend liquid chromatography and typical MS inlets. The 3D-printed sprayers demonstrated exceptional resistance to organic corrosion and high temperatures. For the nanosprayer arrays, an increase in the total electrospray current was achieved by augmenting the number of electrosprays, while maintaining a constant liquid flow rate and voltage. Notably, the eight-nozzle sprayers exhibited a 2.7-fold enhancement in sensitivity as compared with single-nozzle sprayers. This approach offers a versatile and high-sensitivity nanoelectrospray solution for ESI-MS.

Various unique spatial structures are often found in the enzymes of biological systems. From the consideration of bionics, it is challenging but meaningful to design nanozymes with distinctive structures to enhance their bioactivities. To explore the relationship between the structure and activity of nanozymes, in this work, a special structural nanoreactor, namely small pore black TiO 2 coated/doped large pore Fe 3 O 4 (TiO 2 /-Fe 3 O 4 ) loaded with lactate oxidase (LOD), was constructed for chemodynamic and photothermal synergistic therapy. Specifically, LOD loaded on the surface of the TiO 2 /-Fe 3 O 4 nanozyme alleviates the low level of H 2 O 2 in the tumour microenvironment (TME); the black TiO 2 shell with multiple pinhole channels and a large specific surface area not only facilitates LOD loading, but also enhances the affinity of the nanozyme for H 2 O 2 ; H 2 O 2 is continuously enriched on the surface of the TiO 2 /-Fe 3 O 4 nanozyme and transmitted to mesoporous Fe 3 O 4 , in turn efficiently producing abundant toxic hydroxyl radicals (˙OH) for chemodynamic therapy. Meanwhile, the TiO 2 /-Fe 3 O 4 nanozyme under 1120 nm laser irradiation has excellent photothermal conversion efficiency ( η = 41.9%), and further accelerates the production of ˙OH for amplifying the chemodynamic therapy efficiency. This self-cascading, special structure nanozyme provides a novel strategy for application in highly efficient tumour synergetic therapy.

Water pollution caused by antibiotics is a growing problem. Semiconductor photocatalysis is an environmentally friendly technology that can effectively degrade organic pollutants in water. Therefore, the development of efficient photocatalysts is of great significance to solve the environmental pollution problem. In this paper, mixed-phase TiO 2 and 1T/2H-MoS 2 composite (1T/2H-MoS 2 /TiO 2 ) were synthesized by the in situ growth method. The prepared compounds were characterized and applied to the visible-light degradation of tetracycline hydrochloride. The photocatalytic effect of 1T/2H-MoS 2 /TiO 2 on tetracycline hydrochloride is significantly enhanced under visible light and has good stability. It has potential applications in the treatment of organic pollutants in water., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

Graphitic carbon nitride (g-C3N4) is recognized as a favorable substrate for monoatom catalysts due to its uniform nanoholes for anchoring metal monoatoms, while the oxygen evolution reaction (OER) overpotential (ηOER) values of g-C3N4-based metal monoatom catalysts are still large. To reduce the ηOER values, a class of novel TM1NM1NM1/g-C3N4 was designed via density functional theory simulations, where TM1 = Fe1, Co1 or Ni1 and NM1 = C1, N1 or O1. Contributing by two extra-NM1 atoms, the OER catalytic activities of these materials were effectively improved owing to the shortened TM1-NM bonds and weakened chemical activity of TM1 atoms. Based on the volcano activity relationship between the theoretical overpotential (ηOER) and d band center of the TM1 atom (εd), the chemical activity of TM1 atoms needs to be adjusted to a suitable magnitude (εd near -4.883 eV) for a good catalytic activity. The designed Fe1C1O1/g-C3N4 with the εd of -4.893 eV exhibited an excellent OER catalytic activity of ηOER = 0.219 V. This strategy was applied to devise the reaction active sites and highly efficient catalysts by adjusting the chemical activity of the TM1 atom with suitable extra-NM1 atoms.

1T-MoS 2 is in situ grown on TiO 2 nanotubes (TNTs) using a hydrothermal method, forming a 1T-MoS 2 @TNTs composite, which is confirmed by its physical characterization. The prepared composites show enhanced photocatalytic performance for the degradation of tetracycline hydrochloride under visible light, and the improved photocatalytic activity is closely related to the loaded amount of 1T-MoS 2 . Therein, 0.5 wt % 1T-MoS 2 @TNTs can degrade 57% in 1 h, which is the highest photocatalytic efficiency observed in experiments so far. It is speculated that the introduction of 1T-MoS 2 may optimize light absorption and charge separation/transport. The active species are identified and the reaction mechanism is proposed here., Competing Interests: The authors declare no competing financial interest., (© 2021 The Authors. Published by American Chemical Society.)