Chemiluminescence Properties Research Articles

Chemiluminescent carbon dots: Synthesis, properties, and applications

• Chemiluminescent properties and synthetic route of carbon dots are discussed. • Possible mechanism and recent advance in related applications of chemiluminescent carbon dots are identified. • Challenge and prospect in the future development of chemiluminescent CDs are considered. As one of important approaches of light emission, chemiluminescence (CL) induced by chemical reactions has evoked considerable interest for its potential applications in chemical detection, bioanalysis, and cold light source. Carbon dots (CDs) are one kind of emerging carbon nanomaterials for promising CL due to their unique luminescent properties, such as high fluorescence quantum yield, tunable emission wavelength, high photostability, etc . With the special physicochemical property, CDs can take part in the CL reaction as oxidants, emitting species, energy acceptors of chemical reaction energy or even catalysis involving in different CL systems. With these novel influences in CL reaction, these CD-related CL systems have been applied in a broad range of areas. For the reason, CL CDs and their applications such as CL emitting species, catalyst, sensor, information encryption, photodynamic therapy and in-vitro and in-vivo bioimaging/biosensor are reviewed and discussed in this paper. Meanwhile, the challenges and future prospects of the CL CDs have been discussed and proposed.

Multicomponent Reactions: “Kinderleicht”

A demonstration experiment of the synthesis of a novel tetrazole derivative via a multicomponent reaction (Ugi tetrazole four component reaction, UT-4CR) bearing a luminol moiety and a subsequent exploitation of its chemiluminescent properties is described. A complex product is generated in just one simple step, so simple that children can do it: “kinderleicht”, German for dead easy. Students are stimulated, inspired, and involved in a multilevel active learning process using the Steps to Inquiry framework as a metacognitive tool that raises student awareness regarding scientific process and prompts them to ask their own questions discussing the merits of a mechanism and evaluating its effectiveness before they start their own cycles of inquiry.

Ultra-Weak Chemiluminescence Enhanced by Cerium-Doped LaF3 Nanoparticles: A Potential Nitrite Analysis Method.

In this work, cerium-doped LaF3 nanoparticles (LaF3:Ce NPs) were successfully synthesized and characterized. Its chemiluminescence (CL) property was studied, and it was amazingly found that it intensely enhanced the ultra-weak CL of the NaNO2-H2O2 system. The CL mechanism was systematically investigated and suggested to be the recombination of electron-injected and hole-injected LaF3:Ce NPs. The new CL system was developed to be a facile, original, and direct method for nitrite analysis. Experimental conditions were optimized and then a satisfactory linear relationship between CL intensity and nitrite concentration was obtained. This work introduced a new pathway for the research and application of traditional fluoride NPs doped with RE3+.

Computational Insights on the Mechanism of the Chemiluminescence Reaction of New Group of Chemiluminogens-10-Methyl-9-thiophenoxycarbonylacridinium Cations.

Immunodiagnostics, in which one of the promising procedures is the chemiluminescent labelling, is essential to facilitate the detection of infections in a human organism. One of the standards commonly used in luminometric assays is luminol, which characterized by low quantum yield in aqueous environments. Acridinium esters have better characteristics in this topic. Therefore, the search for new derivatives, especially those characterized by the higher quantum yield of chemiluminescence, is one of the aims of the research undertaken. Using the proposed mechanism of chemiluminescence, we examined the effect of replacing a single atom within a center of reaction on the efficient transformation of substrates into electronically excited products. The density functional theory (DFT) and time dependent (TD) DFT calculated thermodynamic and kinetic data concerning the chemiluminescence and competitive dark pathways suggests that some of the scrutinized derivatives have better characteristics than the chemiluminogens used so far. Synthesis of these candidates for efficient chemiluminogens, followed by studies of their chemiluminescent properties, and ultimately in chemiluminescent labelling, are further steps to confirm their potential applicability in immunodiagnostics.

Experimental studies of the effects of global equivalence ratio and CO2 dilution level on the OH* and CH* chemiluminescence in CH4/O2 diffusion flames

Focusing on the chemiluminescent properties of the flame is an effective way to study the flame structure and reaction mechanism. In this paper, based on the CCD camera imaging system, the chemiluminescent distributions of OH* and CH* in CH4/O2 diffusion flames with different global equivalence ratios and CO2 dilution levels were obtained. The changes in the reaction zones of OH* layer and CH* layer were further compared. The peak intensity ratios of OH* and CH* were used to quantitatively characterize the global equivalence ratio and the CO2 dilution level. The results show that variations in the global equivalence ratio and the CO2 dilution level do not obviously alter the shape and thickness of the CH* layer. The distribution and intensity changes of the OH* layer are much more significant than those of the CH* layer when the experimental conditions are varied. For the flame with a low dilution level, the CH* layer is located on the inner rim of the OH* layer, and the radial positions of two peaks are not much different. The increase of the CO2 dilution level leads to the displacement of the OH* peak, which becomes closer to the flame axis. In addition, due to the narrowing of the OH* layer, the CH* layer eventually becomes at the outer rim of the OH* layer. The peak intensity ratio of OH* and CH* decreases linearly with the rise of the global equivalence ratio, and changes as a power function with the increasing CO2 dilution level.

Nonenzymatic chemiluminescence detection of circulating tumor cells in blood based on Au@luminol nanoparticles, hybridization chain reaction and magnetic isolation

Circulating tumor cell (CTC) analysis has great significance for cancer diagnosis and monitoring. However, selective capture and quantification of CTCs from whole blood remains challenging due to the extremely scare number of CTCs. Here, we developed a simple method for ultrasensitive detection of circulating tumor cells (CTCs) based on enzyme-free chemiluminescence reaction, hybridization chain reaction (HCR) signal amplification and magnetic enrichment and isolation. In this detection system, the CTCs-spectific aptamer AS1411 modified magnetic nanoparticles were employed to identify and isolate CTCs from whole blood samples; Au@luminol nanoparticles-HCR assembly (ALHA) containing multiple MUC1 aptamer (specific to a type of CTCs, MCF-7) acted as both the response signal and specific recognition element for sensing CTCs;. On the basis of the chemiluminescence properties of Au@luminol nanoparticles in K2S2O8 solution, the captured CTCs can be sensitively detected using enzyme-free chemiluminescence technique. Furthermore, due to the amplified effect of HCR, the detection sensitivity could be as low as 3 MCF-7 cells /mL. Sensitive, selective results and simple instrument made this method should be useful for further CTCs-related routine applications.

Highly Sensitive Dual-Signal Amplification Electrochemiluminescence Aptasensor Based on Platinum Electrode Modified with Multi-Walled Carbon Nanotubes-Titanium Dioxide and Thionine for Kanamycin Detection

A dual-signal-amplified electrochemiluminescence (ECL) aptasensor based on multi-walled carbon nanotubes@titanium dioxide/thionine (MWCNTs@TiO2/Thi) was proposed to detect kanamycin (KAN) based on the chemiluminescence properties of luminol-hydrogen peroxide (H2O2) in alkaline solution. The MWCNTs@TiO2 with large specific surface area and advantageous biocompatibility could accelerate electron transfer and enable high loading of luminol to enhance ECL intensity. Thi, as a perfect electronic mediator, it can also accelerate electron conductivity to further enhance ECL intensity. With the high charge transfer property of MWCNTs@TiO2 and Thi, the ECL intensity of the aptasensor was obviously promoted. When the target KAN existed, ECL signal decreased significantly due to the specific interaction between KAN and the aptamer. Therefore, KAN concentration could be determined according to the intensity of ECL. Under the optimal conditions, the developed aptasensor showed a wide linear range from 1×10-3 to 1×105 ng mL-1 with a low detection limit of 0.073 ng mL-1 (S/N = 3). The aptasensor showed high specificity, good reproducibility and long-term stability. Simultaneously, the application of the proposed ECL aptasensor will open an efficient approach for highly sensitive detection of KAN in food safety.

One-step fabrication of trimetallic alloy nanozyme catalyzer for luminol-H2O2 chemiluminescence and its application for miRNA-21 detection coupled with miRNA walking machine

PtCuCo trimetallic alloys (PtCuCo-TAs) are synthesized by one-step reduction. The chemiluminescence (CL) properties of PtCuCo-TAs are studied systemically. PtCuCo-TAs show good catalyzing for luminol-H2O2 system. A CL platform is developed for the detection of miRNA-21 using PtCuCo-TAs as nanozyme catalyzer. In the CL detection platform, H1 (Hairpin DNA1) is immobilized onto magnetic beads (MBs) firstly. In the presence of miRNA-21, H1 is opened. H2 (Hairpin DNA2) then hybridizes with H1. Meanwhile, a “cleat” in the end of miRNA-21 with a fewer bases complementary is formed to prevent miRNA-21 dissociating from H1. This miRNA-21 hybridizes to another H1. When cpDNA-PtCuCo-TAs which consisted with cDNA (Complementary strand of probe DNA) and pDNA-PtCuCo-TAs (PtCuCo-TAs labeled with probe DNA) are added, the ssDNA region of H1 reacts with the toehold domain of probe DNA and cDNA is released resulting pDNA-PtCuCo-TAs being captured. With this process repeatedly, a lot of pDNA-PtCuCo-TAs are captured onto MBs. After separation and washing, the precipitate and H2O2 are put into the 96-well and luminol solution is injected. The CL signal is produced by PtCuCo-TAs catalyzing luminol-H2O2 system. The amount of miRNA-21 is detected with CL signal. This CL platform performs with limit of detection 0.167 fM and has good selectivity over other RNA.

Isomeric difference in the crystalline-state chemiluminescence property of an adamantylideneadamantane 1,2-dioxetane with a phthalimide chromophore.

Syn- and anti-isomers of an adamantylideneadamantane 1,2-dioxetane having a phthalimide side chain were prepared and investigated their crystalline-state chemiluminescence (CL) properties. The isomers showed contrastive CL properties depending on their crystal-structural characteristics, indicating that CL provides an attractive target for real-time monitoring of a chemical reaction in the crystal.

Ultrasensitive electrochemiluminescence aptasensor for kanamycin detection based on silver nanoparticle-catalyzed chemiluminescent reaction between luminol and hydrogen peroxide

An ultrasensitive electrochemiluminescence (ECL) aptasensor for detection of kanamycin (KAN) was constructed by using the chemiluminescence properties of luminol-hydrogen peroxide (H2O2) in alkaline solution. Silver nanoparticles (AgNPs) could act as effective catalyzer to accelerate H2O2 decomposition to produce various intermediate reactive oxygen species for signal amplification and thus increased the ECL intensity of luminol. When the target KAN was in the presence, ECL signal decreased obviously owing to the specific interaction between KAN and aptamer. Thus, the concentration of KAN could be determined according to the intensity of ECL. To further demonstrate the effect of aptasensor, we had conducted cyclic voltammetry on an electrochemical workstation and electrogenerated chemiluminescence analyzer, respectively. Upon the optimization of assay conditions, the proposed aptasensor displayed a wide linear range from 0.5 to 100 ng mL−1 with limit of detection of 0.06 ng mL−1. The as-proposed aptasensor was not only capable of achieving a satisfactorily low detection limit but also possessed advantages of excellent accuracy, specificity and stability. Furthermore, this constructed ECL sensing platform was successfully applied to detect KAN in real samples and it would be of excellent potential to detect other antibiotics using the proposed method.

Synthesis and Chemiluminescent Properties of Amino-Acylated luminol Derivatives Bearing Phosphonium Cations.

The monitoring of reactive oxygen species in living cells provides valuable information on cell function and performance. Lately, the development of chemiluminescence-based reactive oxygen species monitoring has gained increased attention due to the advantages posed by chemiluminescence, including its rapid measurement and high sensitivity. In this respect, specific organelle-targeting trackers with strong chemiluminescence performance are of high importance. We herein report the synthesis and chemiluminescence properties of eight novel phosphonium-functionalized amino-acylated luminol and isoluminol derivatives, designed as mitochondriotropic chemiluminescence reactive oxygen species trackers. Three different phosphonium cationic moieties were employed (phenyl, p-tolyl, and cyclohexyl), as well as two alkanoyl chains (hexanoyl and undecanoyl) as bridges/linkers. Synthesis is accomplished via the acylation of the corresponding phthalimides, as phthalhydrazide precursors, followed by hydrazinolysis. This method was chosen because the direct acylation of (iso)luminol was discouraging. The new derivatives’ chemiluminescence was evaluated and compared with that of the parent molecules. A relatively poor chemiluminescence performance was observed for all derivatives, with the isoluminol-based ones being the poorest. This result is mainly attributed to the low yield of the fluorescence species formation during the chemiluminescence oxidation reaction.

Rapid and Quantitative Analysis of Exosomes by a Chemiluminescence Immunoassay Using Superparamagnetic Iron Oxide Particles.

Since the discovery of exosomes, their potential diagnostic value has been the focus of considerable research. However, the lack of a rapid and simple technique for the quantitative analysis of exosomes greatly limits the application of exosomes in clinical research. In this study, we describe a newly developed one-step chemiluminescence immunoassay for the rapid quantitative analysis of exosomes from biofluids. Our new technique, named ExoNANO, adopts a double-antibody sandwich strategy using anti-CD63 antibody-conjugated superparamagnetic iron oxide particles (SIOPs) and acridinium ester (ACE)-labeled anti-CD9 antibodies. SIOPs have narrow size distribution and high magnetic susceptibility, and ACE has excellent chemiluminescent properties such as low background signal and no need for a catalyst. We demonstrated that ExoNANO allows the quantitative analysis of exosomes in the range of 2.92 ×105 to 2.80×108 particles/μL, with a limit of detection of 2.63×105 particles/μL. Using ExoNANO, we quantified exosomes in cell culture medium and clinical biofluids such as serum, saliva, ascitic fluid, and cerebrospinal fluid. We believe that ExoNANO might pave the way for the rapid isolation and quantitative analysis of exosomes for routine clinical applications.

First Synthesis of Highly Chemiluminescent Benzo[b]furan‐2(3H)‐ones Bearing a Urea Substructure

AbstractA series of benzo[b]furan‐2(3H)‐ones (coumaran‐2‐ones) bearing a urea substructure, namely derivatives of 3‐(aminocarbonylamino)benzo[b]furan‐2(3H)‐one, was prepared for the first time. The accessibility of these compounds through an electrophilic α‐amidoalkylation approach of phenols (Tscherniac–Einhorn reaction) in the key step as well as the chemiluminescence (CL) properties of the desired compounds are strongly dependent on the substitution patterns at the urea moiety. Competing reaction pathways are discussed and an improved one pot synthetical approach of also general interest is presented. In conclusion, especially N,N‐dialkylaminocarbonylamino‐derivatives of benzo[b]furan‐2(3H)‐ones exhibit a strong flash like blue CL upon treatment with bases such as 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) in the presence of oxygen or hydrogen peroxide. Comparative physico‐chemical investigations revealed that novel compounds outperform their urethane‐analogues in terms of CL‐intensity and the speed of the decay making them potentially useful as new tools for CL‐based applications on the short time scale.

Highly chemiluminescent TiO2/tetra(4-carboxyphenyl)porphyrin/N-(4-aminobutyl)-N-ethylisoluminol nanoluminophores for detection of heart disease biomarker copeptin based on chemiluminescence resonance energy transfer.

In this work, the chemiluminescence (CL) property of 5,10,15,20-tetrakis(4-carboxyphenyl)-porphyrin- and N-(4-aminobutyl)-N-ethylisoluminol-functionalized TiO2 nanoparticles (TiO2-TCPP-ABEI nanoluminophores) was studied for the first time. It was found that TiO2-TCPP-ABEI nanoluminophores exhibited excellent CL activity in the presence of H2O2. The CL mechanism has been proposed due to the reaction of ABEI with H2O2 and catalytic effect of TiO2 and TCPP. Furthermore, trisodium citrate-stabilized gold nanoparticles were observed to effectively quench the CL of TiO2-TCPP-ABEI due to CL resonance energy transfer (CRET). On this basis, a sensitive and selective CRET-based immunoassay was developed for the determination of copeptin by using TiO2-TCPP-ABEI nanoluminophores as both CL nanointerface and energy donor, and using cit-AuNPs as an effective energy receptor. The immunoassay exhibited a wide dynamic range from 5 × 10-12 to 1 × 10-9gmL-1 with a low detection limit of 1.54 × 10-12gmL-1, which was superior to previously reported CL-based immunoassays. It was successfully applied for the determination of copeptin in serum samples, which would provide a good practical perspective on the clinical diagnosis. This strategy may also be used for the detection of other antigens if corresponding antibodies are available. Graphical abstract.

Electrochemical and chemiluminescence properties of polyaniline/pectin hybrid nanocomposites based on graphene and CdS nanoparticles

Incorporation of CdS nanoparticles is a suitable strategy to improve interfacial features, electrical and optical properties in polyaniline/graphene composites. In the other hand, use of biopolymers in addition to the improvement of processability of polyaniline composites leads to the creation of a developed functional surface owing to the affinity of biopolymers with the surfaces of inorganic nanomaterials. For this purpose in this work, we synthesized a hydrolyzed pectin-polyaniline copolymer (HP-PA) and its nanocomposites with graphene (GR) and CdS nanoparticles via a heterogeneous emulsion polymerization method. The samples were identified by FTIR, XRD, SEM, TEM, EDX, DSC and TGA analyses and investigated via electrical, electrochemical and chemiluminescence properties. Electrical conductivity showed a large increase about three orders of magnitude in conductivity of the nanocomposites compared to the copolymer sample. Electrochemical analyses (CV and EIS) demonstrated higher charge transfer ability for the nanocomposites than the HP-PA copolymer and a substantial improvement in electrochemical performance of GR/CdS@HP-PA due to the reinforcing effect of the CdS nanoparticles in electron transfer process. The optical properties of the samples exhibited a significant enhancement of chemiluminescence intensity for GR/CdS@HP-PA nanocomposite owing to the supporting effect of CdS nanoparticles in electron transfers and light emission.

Synthesis and characterization of cadmium selenide quantum dots doped by europium and investigation of their chemiluminescence properties and antibacterial activities.

Nanoparticles of cadmium selenide (CdSe) doped with europium, were synthesized as stabilizing agents using thioglycolic acid ligand. This method is based on the enhancing effect of CdSe quantum dots (QDs) doped with europium on chemiluminescence (CL) emission. This emission was generated by mixing CdSe QDs with manganese (II), iron (II) and chrome (II) sulfates as catalysts in the presence of hydrogen peroxide (H2 O2 ). The structural characteristics and morphology of these nanoparticles were investigated by scanning electron microscopy, Fourier transform infrared spectroscopy, ultraviolet-visible absorption spectroscopy, X-ray pattern and dynamic light scattering methods. The CdSe QDs doped with europium were used as the sensitizer in a luminol-hydrogen peroxide CL system. The sensitized CdSe QDs were analyzed for antibacterial activity against Gram-positive or Gram-negative bacteria. The results showed that the CdSe QDs are effective against all the studied bacteria, effectiveness was especially higher for Bacillus subtilis.

Quantum chemical approach for chemiluminescence characteristics of di-substituted luminol derivatives in polar solvents

The presence of electron donating substituents altered the electronic properties of the luminol and this phenomenon was evaluated in relation to the chemiluminescence potential of the studied disubstituted luminol derivatives using three different theoretical calculation methods: Restricted Hartree Fork (RHF), Density Functional Theory (DFT) with hybrid function of Becke three-parameters Lee, Yang and Parr (B3LYP), i.e. (DFT-B3LYP), and Møller-Plesset Perturbation Theory (MP2). Different behavior was observed for the studied molecular structures in different phases (gas, water, and dimethylformamide) to emphasize the influence of molecular environment on the chemiluminescence property, regardless of the theoretical methods employed. Time-dependent DFT with correction terms enabled accurate prediction of frontier orbital energies such that calculated energy gaps could reasonably correlate with the lowest excitation energies. Besides, the electron donating moiety induced better chemiluminescence property depending on the donating power, position as well as the number of such substituents. Dimethylamino-substituted luminol showed better quantum chemical parameters and spectra pattern to have much-enhanced chemiluminescence properties possibly. Specifically, its positional isomer named 6,8-bis(dimethylamino)-5-amino-2,3-dihydro-1,4-phthalazinedione showed a greater potential of being a better chemiluminescence reagent in various analytical assays.

Electrochemistry of chemiluminescent novel hybrid nanocomposites based on polyaniline and hydrolyzed pectin with CdS nanoparticles.

Novel hybrid nanocomposites based on polyaniline (PANi), hydrolyzed pectin (HPEc) and CdS nanoparticles (NPs) as electrochemiluminescent biomaterials were prepared. The samples were fabricated via heterogeneous chemical polymerization and studied by FTIR, XRD, SEM, EDX, UV/Vis, TGA and DMTA analyses. The CdS@HPEc-g-PANi nanocomposite was produced via in situ coprecipitation of CdS NPs by direct addition of aqueous cadmium nitrate and sodium sulfide solutions into the polymerization system containing PANi and HPEc. The mCdS@HPEc-g-PANi nanocomposite was synthesized via a new two-step surface modification strategy. The as-prepared CdS NPs synthesized via the chemical precipitation method were modified with epichlorohydrin as an organic reagent to obtain modified CdS (mCdS) and subsequently modified with HPEc and polymerized with aniline hydrochloride to produce mCdS@HPEc-g-PANi. The more smooth morphology of the mCdS@HPEc-g-PANi relative to the CdS@HPEc-g-PANi was approved by the SEM images. The cyclic voltammetry and electrochemical impedance spectroscopy analyses were performed on the samples to evaluate electrochemical properties and the results have indicated the reinforcing effect of the nanoparticles on the electrochemical properties of the nanocomposites. The electrical conductivity measurements by the four probe method have shown a significant increase of electrical conductivity in the presence of the CdS-nanoparticles. The CL experiments confirmed the chemiluminescence effect in the nanocomposites and also higher luminescence intensity for mCdS@HPEc-g-PANi relative to the CdS@HPEc-g-PANi nanocomposite owing to better dispersion of CdS NPs in the former sample.

A conceptual framework for the development of iridium(iii) complex-based electrogenerated chemiluminescence labels.

Translation of the highly promising electrogenerated chemiluminescence (ECL) properties of Ir(iii) complexes (with tri-n-propylamine (TPrA) as a co-reactant) into a new generation of ECL labels for ligand binding assays necessitates the introduction of functionality suitable for bioconjugation. Modification of the ligands, however, can affect not only the photophysical and electrochemical properties of the complex, but also the reaction pathways available to generate light. Through a combined theoretical and experimental study, we reveal the limitations of conventional approaches to the design of electrochemiluminophores and introduce a new class of ECL label, [Ir(C^N)2(pt-TOxT-Sq)]+ (where C^N is a range of possible cyclometalating ligands, and pt-TOxT-Sq is a pyridyltriazole ligand with trioxatridecane chain and squarate amide ethyl ester), which outperformed commercial Ir(iii) complex labels in two commonly used assay formats. Predicted limits on the redox potentials and emission wavelengths of Ir(iii) complexes capable of generating ECL via the dominant pathway applicable in microbead supported ECL assays were experimentally verified by measuring the ECL intensities of the parent luminophores at different applied potentials, and comparing the ECL responses for the corresponding labels under assay conditions. This study provides a framework to tailor ECL labels for specific assay conditions and a fundamental understanding of the ECL pathways that will underpin exploration of new luminophores and co-reactants.

Electrochemiluminescence Immunosensor Based on Platinum Electrode Modified with TiO2@ATO Nanocomposite for Sensitive Detection of AFB1

A novel electrochemiluminescence (ECL) immunosensor was fabricated by using titanium dioxide (TiO2) and antimony tin oxide (ATO) nanocomposite as electrode modified material to detect aflatoxin B1 (AFB1). Luminol with ECL characteristics was modified on the surface of a platinum electrode to prepare the luminescent electrode. The buffer solution contained hydrogen peroxide (H2O2) was used to monitor the ECL signals owing to the chemiluminescence properties of luminol-H2O2 in alkaline solution. TiO2 and ATO were doped with chitosan to form TiO2@ATO nanocomposite, which was modified on the electrode to enhance the ECL intensity by accelerating the electron transfer and provided more binding sites for aflatoxin B1 antibody (Ab) and AFB1. An ECL immunosensor was prepared for AFB1 detection by modifying Ab and bovine serum albumin (BSA) successively. The specific combination of AFB1 and Ab weakened the ECL intensity, thus the concentration of AFB1 was determined according to the strength change of ECL signal. Under optimum conditions, the constructed immunosensor provided a wide linear range from 1.0 × 10−2 to 1.0 × 103 ng mL−1 with a detection limit of 0.03 ng mL−1 (S/N = 3) and showed great specificity and high stability. Furthermore, the proposed immunosensor successfully demonstrated its applicability for detecting AFB1 in peanut oil samples.