Highly chemiluminescent magnetic mesoporous carbon composites Fe3O4@void@C with yolk-shell structure

Fe3O4@void@C-Schiff-base/Pd yolk-shell nanostructures as an effective and reusable nanocatalyst for Suzuki coupling reaction

This article describes the synthesis of a novel Yolk-Shell structured Magnetic Yolk-Shell Nanomaterials Modified by Functionalized Carbon Shell with Schiff/Palladium Bases (Fe3O4@void@C-Schiff-base/Pd). The designed Fe3O4@void@C-Schiff-base/Pd catalyst was characterized using several techniques such as Fourier transform infrared spectroscopy (FTIR), vibrating sample magnetometry (VSM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), thermal gravimetric analysis (TGA), powder X-ray diffraction (PXRD) and Inductively coupled plasma (ICP). The Fe3O4@void@C-Schiff-base/Pd was used as powerful catalyst for preparation Suzuki reaction in short reaction times and high yield in H2O at 60 °C and presence of potassium carbonate base. This nanocatalyst was magnetically recovered and reused several times with keeping its efficiency.

Chemiluminescent magnetic nanoparticles with good catalytic activity and rapid separation capability and sensitive sensing for H2O2

It is of considerable importance to develop chemiluminescent functionalized nanomaterials (CF-NMs) with good catalytic activity, high chemiluminescence (CL) efficiency and good stability, and rapid magnetic separation capability, achieving excellent performance in CL biosensing. In this study, N-(4-aminobutyl)-N-ethylisoluminol (ABEI)-functionalized CuFe2O4 magnetic nanomaterial (ABEI/CuFe2O4) with high catalytic activity was synthesized by virtue of a solvothermal and post-functionalization method. ABEI/CuFe2O4 showed outstanding CL properties, superior to ABEI-CuFe2O4 in liquid phase. This reveals that the immobilization of ABEI on the surface of CuFe2O4 exhibits unique heterogeneous catalytic property. The catalytic ability of CuFe2O4 was better than that of CoFe2O4, ZnFe2O4, MnFe2O4, and NiFe2O4. It is suggested that the peroxide-like activity as well as Cu2+ and Cu0 enriched on the surface of ABEI/CuFe2O4 opened up a dual route for synergistic catalysis of H2O2. ABEI/CuFe2O4 also demonstrated good superparamagnetism and magnetic separation could be carried out in 2 min, which is advantageous for the separation and purification of ABEI/CuFe2O4 during the synthetic procedures and bioassays. Owing to the sensitive response of ABEI/CuFe2O4 to H2O2, an enzyme-free sensor was developed for the detection of H2O2 with a wide linear range over 5 orders of magnitude of H2O2 concentrations and a low detection limit of 5.6 nM. The as-developed sensor is sensitive, stable, and convenient. This work provides a new family member of nanomaterials with good magnetism and CL activity as well as good stability. The developed ABEI/CuFe2O4 shows great prospects in biocatalysis, bioassays, biosensing, and bioimaging, etc.

Nanomaterial-enhanced chemiluminescence reactions and their applications

Chemiluminescence (CL) analysis is a trace analytical method that possesses advantages including high sensitivity, wide linear range, easy operation, and simple instruments. With the development of nanotechnology, many nanomaterial (NM)-enhanced CL systems have been established in recent years and applied for the CL detection of metal ions, anions, small molecules, tumor markers, sequence-specific DNA, and RNA. This review summarizes the research progress of the nanomaterial-enhanced CL systems the past five years. These CL reactions include luminol, peroxyoxalate, lucigenin, ultraweak CL reactions, and so on. The CL mechanisms of the nanomaterial-enhanced CL systems are discussed in the first section. Nanomaterials take part in the CL reactions as the catalyst, CL emitter, energy acceptor, and reductant. Their applications are summarized in the second section. Finally, the challenges and opportunities are discussed.

Carbon dot-based composites for catalytic applications

We summarize the construction methods and influencing factors of CDs-based composites and discuss their catalytic applications, including photocatalysis, chemical catalysis, peroxidase-like catalysis, Fenton-like catalysis and electrocatalysis.

Chemiluminescence Immunoassays for Simultaneous Detection of Three Heart Disease Biomarkers Using Magnetic Carbon Composites and Three-Dimensional Microfluidic Paper-Based Device

Chemiluminescence (CL) immunoassays for simultaneous detection of early acute myocardial infarction (AMI) biomarkers, including copeptin, heart-type fatty acid binding protein (h-FABP), and cardiac troponin I (cTnI), were developed by using Co²⁺/N-(aminobutyl)-N-(ethylisoluminol) (ABEI) functionalized magnetic carbon composite (Co²⁺-ABEI-Fe₃O₄@void@C) as an interface and a three-dimensional microfluidic paper-based device (3D μPAD) as a detection system. For CL immunoassays, Co²⁺-ABEI-Fe₃O₄@void@C was assembled with chitosan (CS) and gold nanoparticle-conjugated antibody (Au-Ab) sequentially to form the sensing platform (Co²⁺-ABEI-Fe₃O₄@void@C-CS/Au-Ab). In the presence of antigen (Ag), Ag was captured by the sensing interface to form an immunocomplex, leading to an increase in CL intensity due to the catalysis of -COO^- existing in Ag. A 3D μPAD with three detection zones for simultaneous detection of copeptin, h-FABP, and cTnI was designed and fabricated to obtain time-resolved CL signals. Three kinds of immunocomplexes formed with copeptin, h-FABP, and cTnI were added to three detection zones of 3D μPAD, respectively. After injecting H₂O₂, three time-resolved CL signals were generated in one CL detection run by virtue of time-delayed transport of H₂O₂ to different detection zones. The three time-resolved CL signals were used for the simultaneous determination of copeptin, h-FABP, and cTnI. The detection limit of copeptin, h-FABP, and cTnI was 0.40 pg/mL, 0.32 pg/mL, and 0.50 pg/mL, respectively, which is at least 1 order of magnitude lower than most of the reported immunoassays. The immunoassays could be directly used for the detection of copeptin, h-FABP, and cTnI in human serum samples. The proposed immunoassays are simple, fast, sensitive, and selective, and are of great application potential in early diagnosis and treatment of AMI.