Direct and Indirect Chemiluminescence: Reactions, Mechanisms and Challenges

The phenomenon can take place both in natural and artificial chemical systems and it has been utilized in a variety of applications. In this review, we aim to revisit some of the latest CL applications based on direct and indirect production modes. The characteristics of the chemical reactions and the underpinning CL mechanisms are thoroughly discussed in view of studies from the very recent bibliography.
Different methodologies aiming at higher CL efficiencies are summarized and presented in detail, including CL type and scaffolds used in each study. The CL role in the development of efficient therapeutic platforms is also discussed in relation to the Reactive Oxygen Species (ROS) and singlet oxygen (1O2) produced, as final products.
Moreover, recent research results from our team are included regarding the behavior of commonly used photosensitizers upon chemical activation under  CL conditions. The CL prospects in imaging, biomimetic organic and radical chemistry, and therapeutics are critically presented in respect to the persisting challenges and limitations of the existing strategies to date.

A Novel Brighter Bioluminescent Fusion Protein Based on ZZ Domain and Amydetes vivianii Firefly Luciferase for Immunoassays

Immunoassays are widely used for detection of antibodies against specific antigens in diagnosis, as well as in electrophoretic techniques such as Western Blotting. They usually rely on colorimetric, fluorescent or chemiluminescent methods for detection. Whereas the chemiluminescence methods are more sensitive and widely used, they usually suffer of fast luminescence decay. Here we constructed a novel bioluminescent fusion protein based on the N-terminal ZZ portion of protein A and the brighter green-blue emitting Amydetes vivianii firefly luciferase.
In the presence of D-luciferin/ATP assay solution, the new fusion protein displays higher bioluminescence activity, is very thermostable and produces a sustained emission (t1/2 > 30 min). In dot blots, we could successfully detect rabbit IgG against firefly luciferases, Limpet Haemocyanin, and SARS-CoV-2 Nucleoprotein (1-250 ng), as well as the antigen bound antibodies using either CCD imaging, and even photography using smartphones. Using CCD imaging, we could detect up to 100 pg of SARS-CoV-2 Nucleoprotein.
Using this system, we could also successfully detect firefly luciferase and SARS-CoV-2 nucleoprotein in Western Blots (5-250 ng). Comparatively, the new fusion protein displays slightly higher and more sustained luminescent signal when compared to commercial HRP-labeled secondary antibodies, constituting a novel promising alternative for Western Blotting and immunoassays.

Long-Lasting Luminol Chemiluminescence Emission with 1,10-Phenanthroline-2,9-dicarboxylic Acid Copper(II) Complex on Paper

As most of the known systems are flashtype, long-lasting chemiluminescence (CL) emissions are extremely needed for the application of cold light sources, accurate CL quantitative analysis, and biological mapping. In this work, the flashtype system of luminol was altered to a long lasting CL system just because of the paper substrate. The Cu(II)-based organic complex was loaded on the paper surface, which can trigger luminol-H2O2 to produce a long lasting CL emission for over 30 min.
By using 1,10-phenanthroline-2,9-dicarboxylic acid (PDA) as the ligand, a hexacoordinated Cu(II)-based organic complex was synthesized by the simple freeze-drying method. It is interesting that the complex morphology can be controlled by adding different amounts of water in the synthesizing procedure. The complex with a certain size can be definitely trapped in the pores of the cellulose.
  • Then, slow diffusion, which can be attributed to the long lasting CL emission, was produced. With the high catalytic activity of the complex, reactive oxygen species from H2O2 was generated and was responsible for the high CL intensity.
  • By using the paper substrate, the flash-type luminol system can be easily transferred to the long-duration CL system without any extra reagent.
  • This long-lasting emission system was used for hydrogen sulfide detection by the CL imaging method.
  • This paper-based sensor has great potential for CL imaging in the clinical field in the future.

Insight into the Ozone-Assisted Low-Temperature Combustion of Dimethyl Ether by Means of Stabilized Cool Flames

The low-temperature combustion kinetics of dimethyl ether (DME) were studied by means of stabilized cool flames in a heated stagnation plate burner configuration using ozone-seeded premixed flows of DME/O2. Direct imaging of CH2O* chemiluminescence and laser-induced fluorescence of CH2O were used to determine the flame front positions in a wide range of lean and ultra-lean equivalence ratios and ozone concentrations for two strain rates.
The temperature and species mole fraction profiles along the flame were measured by coupling thermocouples, gas chromatography, micro-chromatography, and quadrupole mass spectrometry analysis. A new kinetic model was built on the basis of the Aramco 1.3 model, coupled with a validated submechanism of O3 chemistry, and was updated to improve the agreement with the obtained experimental results and experimental data available in the literature.
The main results show the efficiency of the tested model to predict the flame front position and temperature in every tested condition, as well as the importance of reactions typical of atmospheric chemistry in the prediction of cool flame occurrence. The agreement on the fuel and major products is overall good, except for methanol, highlighting some missing kinetic pathways for the DME/O2/O3 system, possibly linked to the direct addition of atomic oxygen on the fuel radical, modifying the product distribution after the cool flame.

Advanced image analysis-based evaluation of protein antibody microarray chemiluminescence signal improves glioma type identification by blood serum proteins concentrations

Background and objective: Gliomas are the most common brain tumors usually classified as benign low-grade or aggressive high-grade glioma. One of the promising possibilities of glioma diagnostics and tumor type identification could be based on concentration measurements of glioma secreted proteins in the blood.
However, several published approaches of quantitative proteomic analysis emphasize limits of one single protein to be used as biomarker of these types of tumors. Simultaneous multi-protein concentrations analysis giving antibody array-based methods suffer from poor measurement accuracy due to technical limitations of imaging systems.
Methods: We applied Principal Component Analysis (PCA) for series of repeated antibody array chemiluminescence images to extract the component representing relative values of protein concentrations, free from zero-mean noise and uneven background illumination – main factors corrupting evaluation result.
Results: The proposed method increased accuracy of protein concentration estimates at least 2-fold. Decision tree classifier applied to the relative concentration values of three proteins TIMP-1, PAI-1 and NCAM-1 estimated by proposed image analysis method effectively distinguished between low-grade glioma, high-grade glioma and healthy control subjects showing validation accuracy of 74.9% with the highest positive predictive value of 81.2% for high-grade glioma and 57.1% for low-grade glioma cases.

PolyTek HRP Anti-Rabbit Polymerized Imaging System

PIP080 ScyTek Laboratories 1 kit(s) 187.2 EUR

PolyTek Anti-Mouse (DAB) Polymerized HRP Imaging System

PIR080 ScyTek Laboratories 70 Slides 187.2 EUR

EzScope 101 Live Cell Imaging System with 10x objective lens

COU2050 Scientific Laboratory Supplies EACH 4979.52 EUR

SuperBrite? ELISA HRP Chemiluminescence Substrate Kit

K4005-500 Biovision each 216 EUR

Accuris SmartDoc 2.0 Imaging Enclosure

E5001-SD Benchmark Scientific 1 PC 500.82 EUR

Accuris SmartDoc 2.0 Imaging Enclosure

ELE1250 Scientific Laboratory Supplies EACH 518.7 EUR

ProtoBlock System

NAT1004 Scientific Laboratory Supplies 1KIT 71.82 EUR

New system

VS10WPGS2 Scientific Laboratory Supplies EACH 80.94 EUR

Cell Meter™ Autophagy Fluorescence Imaging Kit

23001 AAT Bioquest 200 Tests 367.2 EUR

MycoLight™ Live Bacteria Fluorescence Imaging Kit

22409 AAT Bioquest 100 Tests 367.2 EUR

Accuris SmartDoc Band Pass Filter Imaging Green

ELE1253 Scientific Laboratory Supplies EACH 152.76 EUR

Accuris SmartDoc Band Pass Filter Imaging EtBR

ELE1254 Scientific Laboratory Supplies EACH 152.76 EUR

Cell Navigator®CDy6 Mitosis Imaging Kit

22640 AAT Bioquest 100 Tests 318 EUR

High-Sensitive ECL Chemiluminescence Detection Kit (Ready-to-Use)

E412-01 Vazyme 2 × 50 ml 180 EUR

High-Sensitive ECL Chemiluminescence Detection Kit (Ready-to-Use)

E412-02 Vazyme 250 ml 393.6 EUR

GloBrite chemiluminescence reagent kit for western blotting 200 mL

GLB1 Detroit R&D 200 mL 174 EUR

GloBrite chemiluminescence reagent kit for western blotting 500 mL

GLB2 Detroit R&D 500 mL 280.8 EUR

T-Pro LumiFast Plus Chemiluminescence Detection Kit (ECL Kit)

JT96-K002M T-Pro Biotechnology 250ml*2/Kit 244.8 EUR

T-Pro LumiFast Plus Chemiluminescence Detection Kit (ECL Kit)

JT96-K002S T-Pro Biotechnology 100ml*2/Kit 182.4 EUR

T-Pro LumiLong Plus Chemiluminescence Detection Kit (ECL Kit)

JT96-K004M T-Pro Biotechnology 250ml*2/Kit 286.8 EUR

T-Pro LumiLong Plus Chemiluminescence Detection Kit (ECL Kit)

JT96-K004S T-Pro Biotechnology 100ml*2/Kit 204 EUR

MycoLight™ Fluorescence Live/Dead Bacterial Imaging Kit

22411 AAT Bioquest 100 Tests 446 EUR

AEC coloring system

CT356 U-CyTech 10-plate 169.2 EUR

data acquisition system

D230 Consort ea 2044.8 EUR

CometAssay Electrophoresis System

4250-050-ES Biotechne 1 Kit 3540.96 EUR