Luminol Chemiluminescence System Research Articles

Carbon Vacancy-Enhanced Activity of Fe-N-C Single Atom Catalysts toward Luminol Chemiluminescence in the Absence of H2O2.

The classic luminol-H2O2 chemiluminescence (CL) systems suffer from easy self-decomposition of H2O2 at room temperature, hindering the practical applications of the luminol-H2O2 CL system. In this work, unexpectedly, we found that the carbon vacancy-modified Fe-N-C single atom catalysts (VC-Fe-N-C SACs) can directly trigger a luminol solution to generate strong CL emission in the absence of H2O2. The Fe-based SACs were prepared through the conventional pyrolysis of zeolitic imidazolate frameworks. The massive carbon vacancies were readily introduced into Fe-N-C SACs through a tannic acid-etching process. Carbon vacancy significantly enhanced the catalytic activity of Fe-N-C SACs on the CL reaction of luminol-dissolved oxygen. The VC-Fe-N-C SACs performed a 13.4-fold CL enhancement compared with the classic luminol-Fe2+ system. It was found that the introduction of a carbon vacancy could efficiently promote dissolved oxygen to convert to reactive oxygen species. As a proof of concept, the developed CL system was applied to detect alkaline phosphatase with a linear range of 0.005-1 U/L as well as a detection limit of 0.003 U/L. This work demonstrated that VC-Fe-N-C SAC is a highly efficient CL catalyst that can promote the analytic application of the luminol CL system.

Nanozyme-Based Biofuel Cell Ingeniously Coupled with Luminol Chemiluminescence System through In Situ Co-Reactant Generation for Dual-Signal Biosensing.

Classical luminol-based chemiluminescence (CL) is the process of emitting light enhanced by the addition of coreactant hydrogen peroxide (H2O2). To address the instability issue of H2O2 decomposition, herein, we proposed a nanozyme-based biofuel cell (BFC) ingeniously coupled with a luminol CL system via in situ generation of H2O2. Specifically, the gold nanoparticle (AuNP) nanozyme with glucose oxidase-like activity can act as the anodic enzyme of BFC to catalyze the oxidation of glucose to produce H2O2 and electrons. In this case, H2O2 as a coreactant enhanced the CL intensity and the cathode of the BFC obtained electrons to generate the open circuit voltage (EOCV) signals. As a result, a dual-signal biosensing platform was successfully constructed. Interestingly, the AuNPs-catalyzed system operates in an alkaline medium, which precisely meets the pH requirement for luminol luminescence. Such a BFC-CL system not only greatly lessens the effect of unstable exogenous H2O2 on the signal stability but also enhances the CL of luminol. Furthermore, both CL and EOCV signals present a positive correlation with the glucose concentration. Therefore, this novel BFC-CL system shows good performance for dual-signal biosensing, which would serve as a valuable guideline for the design and application of BFC-based self-powered or CL biosensors.

Laccase-luminol chemiluminescence system: an investigation of substrate inhibition.

Chemiluminescence (CL) reactions are widely used for the detection and quantification of many types of analytes. Laccase has previously been proposed in CL reactions; however, its light emission behaviour has not been characterized. This study was conducted to characterize the laccase-luminol system, determine its kinetic parameters, and analyze the effects of protein and OH- concentration on the CL signal. Laccase from Coriolopsis gallica was combined with different concentrations of luminol (125 nM to 4 mM), and the enzyme kinetics were evaluated using diverse kinetic models. The laccase-luminol system was able to produce CL without an intermediate molecule, but it exhibited substrate-inhibition behaviour. A two-site random model was used and suggested that when the first luminol molecule was bound to the active site, laccase affinity for the second luminol molecule was increased. This inhibition effect could be avoided using a low luminol concentration. At 5 μM luminol concentration, 1mg/ml (0.13 U) laccase is needed to achieve nearly 90% of the maximum CL signal, suggesting that the available luminol could not bind to all active sites. Furthermore, the concentration of NaOH negatively affected the CL signal. The laccase-luminol system represents an alternative to existing CL systems, with potential uses in molecular detection and quantification.

The Determination Method of Total Polyphenol in Tea and Substitute Tea Based on [Ag(HIO6)2]5--Luminol Chemiluminescence System.

Scientific, accurate, and rapid detection of the composition and content of tea polyphenols is an important basis for their rational use and giving full play to their physiological effect. The spectrophotometric assays for total polyphenols have poor selectivity. Therefore, there is a need to develop a simple and reliable method for the determination of the total polyphenolic level in tea products. The aim of this research was to develop a flow injection chemiluminescence (FI-CL) method based on the Ag(III)-luminol system for the total polyphenol content analysis of tea and substitute tea. Through Box-Behnken experimental design, we selected the optimum determination condition. The Ag(III) concentration was 5 × 10-5 mol/L, and the luminol concentration was 3 × 10-7 mol/L (including 0.15 mol/L NaOH). The peristaltic pump is 25 r/min, and the photomultiplier voltage is 600 v. Sample extracts were diluted 100 000 times for the FI-CL assay. Under optimal conditions, CL intensities were proportional to total polyphenol content (in terms of gallic acid concentrations) in the range of 0.1∼100 μg/L. The LOD and LOQ were 0.03 μg/L and 0.1 μg/L. The recovery values were in the range of 86.3-111.0% with a RSD of 1.04∼2.62%. The polyphenolic content of 12 teas and 6 substitute teas was determined, and the results of the developed method and Folin-Ciocalteu method were highly correlated (r = 0.9493 for tea and r = 0.8533 for substitute tea). The proposed method is better than the Folin-Ciocalteu method in terms of selectivity, sensitivity, and accuracy. It is suitable for the determination of polyphenol content not only in tea, but also in substitute tea. We developed a new flow-injection analysis method for polyphenolic content determination based on the Ag(III)-luminol chemiluminescence system. It is simple, rapid, sensitive, and accurate. It is suitable for the determination of polyphenols content not only in tea, but also in substitute tea.

A miniature chemiluminescence spectrometric system induced by atmosphere microplasma jet to avoid using hydrogen peroxide and catalyst

A miniature luminol chemiluminescence system based on atmosphere microplasma is proposed for detection without any catalysts. In our research, atmosphere microplasma jet is employed to oxidize luminol and produce chemiluminescence instead of H2O2. The transport of OH radicals to the plasma-liquid interface and induce the chemiluminescence. The weight of the system is only 3.6 kg (including a 1.2 kg laptop), and the power consumption of the microplasma is only 0.045 W. The mechanism of luminol chemiluminiscence induced by microplasma jet and generation of microplasma jet are investigated in this study. A 1 mL sample solution is sufficient for trace 3-NPA determination within an analysis time of 6 min. In the range of 0.03–10 mg L−1, 3-NPA can be quantitatively analyzed along with a detection limit of 0.008 mg L−1. In addition, the proposed system is employed for real-world samples detection, including water samples, brown sugar and tainted sugarcane, which demonstrates the reliability and practical feasibility of the detection method.

Carbon dots-peroxyoxalate micelle as a highly luminous chemiluminescence system under physiological conditions

Chemiluminescence (CL) has been widely used for bioanalysis owing to its high sensitivity, low background and simplicity. However, most of the CL systems need acidic/alkaline conditions or organic solvent to enhance their luminescent efficiency, and the non-physiological conditions can usually lead to the misfunction of biomolecules during biosensing. Herein, we report a highly luminous CL system under physiological conditions based on carbon dots-bis(2-carbopentyloxy-3,5,6-trichlorophenyl) oxalate (CDs-CPPO) micelles, and further used it in biosensing application. In the CL system, the amphiphilic surfactant packed CPPO and hydrophobic CDs together to form CDs-CPPO micelles. Such micelles solution not only isolated the CPPO from water to prevent its hydrolysis but also made the close proximity between CPPO and CDs, thus significantly enhancing the CDs quantum yield. The CL quantum yield was calculated to be 5.26 × 10−4 einsteins/mol, about 200-fold higher than that of the most commonly used luminol CL system. The oxidases (e.g., glucose oxidase) were tested to be susceptible to the organic solvent and non-physiological pH. Hence, the CL system was used for the detection of oxidase substrates (exemplified by glucose) in serum samples, and the limit of detection was as low as 8.4 nmol/L. The highly luminous CL system that can work under physiological conditions is promising for biosensing applications

A novel metal organic gel with superior oxidase-like activity for efficient and sensitive chemiluminescence detection of uric acid

It is found that MIL-100(Fe) gels, as a kind of metal-organic gels (MOGs), constitutting of iron (Fe3+) and trimesic acid (H3BTC), has been regarded as the efficient catalyst of luminol chemiluminescence (CL) system without the presence of extra oxidants in the present work. MIL-100(Fe) gels that have possessed mimicking oxidase-like activity can excellently enhanced luminol CL intensity by accelerating the generation of reactive oxygen species. Furthermore, with the addition of uric acid (UA), the CL signal has been dramatically inhibited under alkaline condition. Hence, the CL intensity inhibiting ratio (I0/IS) was proportional to the increasing concentration of UA in the rang from 10 nM to 4000 nM with the detection limit of 5.9 nM. This method has been successfully applied for analysis of UA with acceptable recoveries ranging from 97.0% to 107.9% in urine sample. These results indicates that this study open up a novel, sensitive and convenient method to detect UA in biological samples.

A novel luminol chemiluminescence induced by photoexcited ketones: A selective determination method for acetone in wastewater

It has been recently confirmed that photoexcited ketones such as acetone promote the chemiluminescence (CL) reaction of luminol and its analog, L-012. Using this finding, a selective determination method for acetone was developed herein based on HPLC separation, online UV irradiation, and subsequent luminol CL detection. Various conditions, including the type of luminol reagent, the use of organic solvents as eluent modifiers, and the reaction pH, were investigated to elucidate the CL reaction mechanism. The results showed that the CL reaction of luminol is caused by an acetone ketyl radical produced from the photoexcited acetone. The performance of the novel acetone determination method was evaluated by its application in water quality assurance in water treatment plants. The method detection limit and the method quantification limit of acetone were 0.03 and 0.08 µM, respectively. A linear range was obtained in the concentration range of 0.1–200 µM. The range of recovery in the wastewater and seawater samples (n = 5) fortified with 5.0 µM acetone was 87–108%. These results demonstrate that the new luminol CL system is useful for its sensitivity and selectivity.

A novel luminol chemiluminescence system induced by black phosphorus quantum dots for cobalt (II) detection

Black phosphorus quantum dots (BP QDs) were prepared through a solvothermal exfoliation method in alkaline N-methyl-2-pyrrolidinone. The BP QDs induce distinct chemiluminescence (CL) of alkaline luminol directly. A possible reaction mechanism is proposed by the study of CL spectrum, ultraviolet–visible absorption spectra, electron paramagnetic resonance spectra as well as radical scavenging experiments. The presence of BP QDs significantly increases generation of active oxygen species, which oxidize luminol and lead to intense CL emission at 425 nm. The reaction of luminol with BP QDs are specifically catalyzed by cobalt (II) ion, this presents a sensitive CL method for cobalt (II) ion. A linear response range extends from 2.5 to 2000.0 pmol/L cobalt (II) ion and a detection limit of 0.7 pmol/L (3sb) is acquired. The method displays a good precision approved by a relative standard deviation of 1.9% at 100.0 pmol/L cobalt (II) ion solution (n = 11). A preliminary application of the method was conducted by successful determination of cobalt amount in silica gel and rain water samples.

Paper-based Chemiluminescence Device with Co-Fe Nanocubes for Sensitive Detection of Caffeic Acid.

In this work, a new chemiluminescence (CL) system of Co-Fe prussian blue analogs nanocubes (Co-Fe PBA NCs) that can catalyze luminol to produce strong CL in the absence of H2O2 was established. Co-Fe PBA NCs have the property of oxidase-like activity, and it can catalyze the generation of active oxygen radicals in a dissolved oxygen system. Since caffeic acid (CA) can remove reactive oxygen species in the system, a sensitive detection method for CA on a paper-based chip was developed. Under the optimal conditions, this method showed a good linear response to CA in the range of 10 - 800 ng mL-1 with a limit of 3 ng mL-1. The proposed method had been used for the determination of CA in tea samples. The results may open a new avenue for the catalytic property on luminol CL system without extra oxidants.

Determination of monoamine neurotransmitters and metabolites by high-performance liquid chromatography based on Ag(III) complex chemiluminescence detection

A novel, simple and efficient chemiluminescence system has been developed for the determination of monoamine neurotransmitters and metabolites. By using the Ag (III)-luminol chemiluminescence system as a detector, a high performance liquid chromatography chemiluminescence method (HPLC-CL) was established and used to detect seven monoamine neurotransmitters. Under the optimized conditions, the detection limits (3S/N) of epinephrine (E), levodopa (l-DOPA), dopamine (DA), serotonin (5-HT), 3-methoxy-4-hydroxyphenylglycol (MHPG), 3,4-dihydroxyphenylacetic acid (DOPAC) and 5-hydroxypentylacetic acid (5-HIAA) were 20.0 μg dm−3,15.0 μg dm−3, 15.0 μg dm−3, 8.0 μg dm−3, 2.0 μg dm−3, 2.0 μg dm−3 and 3.0 μg dm−3, respectively. Moreover, they were well within the linear range of 50–1000 μg dm−3, 50–1000 μg dm−3, 50–1000 μg dm−3, 25–1000 μg dm−3, 5–25 μg dm−3, 5–25 μg dm−3 and 10–30 μg dm−3, respectively. The average recovery varied between 84.82% and 110.4%. The method has the attributes of simplicity, high sensitivity, and high efficiency. The sensitization and inhibition mechanisms for luminol-[Ag(HIO6)2]5–- analytes CL system were proposed by CL spectra and free-radical capture experiment.

A covalent triazine framework as an oxidase mimetic in the luminol chemiluminescence system: application to the determination of the antioxidant rutin.

It is found that a covalent triazine framework (CTF-1) (that was prepared from 1,4-dicyanobenzene) exhibits oxidase-like activity toward the oxidation of luminol with dissolved oxygen in alkaline condition to produce intense blue chemiluminescence (CL). The reaction follows Michaelis-Menten kinetics and shows strong specificity for luminol. Reactive oxygen species including 1O2, •OH and O2•- are testified to be involved in the reaction and responsible for the CL. The reaction was applied to the determination of the radical-scavenging activity of antioxidants, with rutin, kaempferol and ferulic acid serving as model scavengers. A sensitive CL method was developed for the determination of rutin based on its inhibitory effect on the reaction. The CL system gave a linear response to the concentration of rutin in the range of 0.03-0.25μmol·L-1 with a limit of detection of 0.015μmol·L-1. The practicability of the method was demonstrated by successful determination of rutin in tablets and in Flos Sophorae Immaturus. Graphical Abstract.

Gold Nanoparticle Size-Dependent Enhanced Chemiluminescence for Ultra-Sensitive Haptoglobin Biomarker Detection.

Bovine mastitis (BM) is a frequent disease in the dairy industry that causes staggering economical losses due to decreased milk production and increased health care costs. Traditionally, BM detection depends on the efficacy and reliability of analytical techniques that measure somatic cell counts (SCC), detect pathogens, and reveal inflammatory status. Herein, we demonstrate the detection of bovine haptoglobin, a well-documented acute phase protein for evaluating BM clinical status, by utilizing hemoglobin-binding capacity within luminol chemiluminescence (CL) system. The resulting haptoglobin–hemoglobin complex reduces the CL signal proportionally to inherent haptoglobin concentrations. Different sizes of cross-linked gold nanoparticles (GNPs) were examined for enhanced CL (eCL) signal amplification, presenting over 30-fold emitted radiation enhancement for optimized size within real milk samples with respect to nanoparticle-free assay. The eCL values were proportionally related to nanoparticle size and content, influenced by SCC and pathogen type (e.g., Escherichia coli and coagulase-negative staphylococci). The optimized bioassay showed a broad linear response (1 pg mL−1–10 µg mL−1) and minute detection limit of 0.19 pg mL−1, while presenting quantitative performance in agreement with commercial ELISA kit. Finally, the resulting optimized eCL concept offers an efficient label-free detection of haptoglobin biomarker, offering means to diagnose the severity of the associated diseases.

Milk haptoglobin detection based on enhanced chemiluminescence of gold nanoparticles

The suggested research specifically addresses the major source of economic loss of the dairy industry, the bovine mastitis (BM), an inflammatory disease of mammary gland caused by bacterial intramammary infection. During udder inflammation, the concentrations of acute phase proteins (APP) in both plasma and milk are escalated, which can be distinctively utilized as predicting diagnostic biomarkers of cattle's BM clinical status. Herein, we demonstrate a liquid-phase luminol chemiluminescence (CL) system for sensitive detection of haptoglobin (Hp), a predictive APP of BM, by utilizing the binding capacity of hemoglobin (Hb). The CL intensity is linearly proportional to Hb-Hp complex formation, resulting in peroxidase-like activity inhibition of luminol-H2O2-Hb CL system. Enhanced CL, at least 10-fold effect within real samples, is attained by the addition of catalytically active cross-linked gold nanoparticles (GNPs) onto the luminol-H2O2 solution. Moreover, the influence of different somatic cell counts (representing subclinical and clinical BM status) and pathogen types (i.e., CNS and Streptococcus dysgalactiae) on the secreted milk Hp levels obtained from Holstein cows are established. The analyzed Hp concentrations are in agreement with a commercial enzyme-linked immunosorbent assay kit. The proposed CL sensing concept offers cost-effective, simple, label-free and reliable systematic analysis of Hp biomarker for BM, potentially initiating a positive effect on animals’ health and overall economy of the dairy farms.

Novel Iron(III)-Based Metal-Organic Gels with Superior Catalytic Performance toward Luminol Chemiluminescence.

Novel metal-organic gels (MOGs) consisting of iron (Fe3+) as the central ion and 1,10-phenanthroline-2,9-dicarboxylic acid (PDA) as the ligand were synthesized by a mild facile strategy. The Fe(III)-containing metal-organic xerogels (Fe-MOXs), obtained after removing the solvents in MOGs, were found to exhibit outstanding performance in the catalysis of luminol chemiluminescence (CL) for the first time even in the absence of extra oxidants such as hydrogen peroxide. The possible CL mechanism was discussed according to the electro/optical measurements, including electron paramagnetic resonance (EPR), UV-vis absorption, and CL spectra, as well as the effects of radical scavengers on Fe-MOXs-catalyzed luminol CL system, suggesting that the CL emission of luminol might originate from the intrinsic oxidase-like catalytic activity of Fe-MOXs on the decomposition of dissolved oxygen. Additionally, the potential practical application of the resulting luminol-Fe-MOXs system was evaluated by the quantitative analysis of dopamine. Good linearity over the range from 0.05 to 0.6 μM was obtained with the limit of detection (LOD, 3σ) of 20.4 nM and acceptable recoveries ranging from 98.6 to 105.4% in human urine. These results may open up the promising application of novel metal-organic gels as highly effective catalysts in the field of chemiluminescence.

Paper-based chemiluminescence immunodevice with temporal controls of reagent transport technique

A paper-based chemiluminescence (CL) immunodevice for detection of three biomarkers with the temporal controls of reagent transport technique was developed in this work. Sugar barriers were built on the paper-based chip for the controlled reagent transport technique to create programmable flow delays for the later CL detection. Different amount of sucrose which can manipulate the reagent migration rate was drawn precisely on the microchannels by a craft-cutting instrument. The paper-based immunodevice with three channels was fabricated by the cutting method. Also the localized incision protocol with one side adhesive tape and paper-folding method were adopted here to isolate the detection zone from flow channels. This simple origami step of the detection zone can eliminate possible reagent diffusion and flowing during antibody immobilization steps and numerous washings. By using the gold nanoparticles (AuNPs) as the carrier for loading multi horseradish peroxidase (HRP) labeled signal antibody, greatly enhanced sensitivity was achieved by HRP catalyzed luminol CL system. Under a sandwich immunoassay, carcinoembryonic antigen (CEA), carcinoma antigen 125 (CA125) and carbohydrate antigen 199 (CA199) were detected on the paper-based chip. A limit of detection (LOD) of 0.03ng/mL, 0.2U/mL, 0.2U/mL was demonstrated, respectively. We believe that this paper-based CL immunodevice with controlled reagent transport technique can provide a new strategy of sensitive detection of multi-biomarkers in point-of-care (POC) diagnostics field.

DPPH·-luminol chemiluminescence system and its application in the determination of scutellarin in pharmaceutical injections and rat plasma with flow injection analysis.

In this article, a DPPH·-luminol chemiluminescence (CL) system was reported and the CL mechanism was discussed according to the CL kinetic properties after sequence injecting DPPH· into the DPPH·-luminol reaction mixture. It was observed that scutellarin could inhibit the CL response of the DPPH·-luminol system. Based on this observation, a simple and rapid flow injection CL method was developed for the determination of scutellarin using the inhibition effect in alkaline medium. The optimized chemical conditions for the CL reaction were 5×10-6 mol/L DPPH· and 1.0×10-4 mol/L luminol in 0.01mol/L NaOH. Under optimized conditions, the CL intensity was inversely proportional to the concentration of scutellarin over the ranges 5-2000 and 40-3200ng/ml in pharmaceutical injection and rat plasma, respectively. The limits of detection (S/N=3) were 5 and 40ng/ml in preparations and rat plasma, respectively. Furthermore, the precision, recovery and stability of the validated method were acceptable for the determination of scutellarin in both pharmaceutical injections and rat plasma. The presented method was successfully applied in the determination of scutellarin in pharmaceutical injections and real rat plasma samples.

Determination of Glucose and Cholesterol Using a Novel Optimized Luminol- CuO Nanoparticles-H2O 2 Chemiluminescence Method by Box-Behnken Design.

In this study, a simple, rapid and sensitive luminol-CuO nanoparticles-H2O2 chemiluminescence (CL) method has been proposed for determination of glucose and cholesterol in plasma. Response surface methodology (RSM) based on Box-Behnken design (BBD) was used to optimize the most important operating variables (solution pH effect and the CL reagents concentration) of luminol CL system. In optimum conditions, it was found that CuO nanoparticles (NPs) could enhance the CL intensity and the method sensitivity towards evaluation of trace amount of glucose and cholesterol. Under the optimal conditions, there is a good linear relationship between the luminol-CuO NPs - H2O2 relative CL intensity and the concentration over the range of 1.2 × 10(-6)-1.0 × 10(-3) M (R (2) = 0.9991) for glucose and 2.5 × 10(-5)-CuO NPs7.17 × 10(-3) M (R (2) = 0.9968) for cholesterol and with a 3σ detection limit of 7.1 × 10(-7) and 6.4 × 10(-6) M, respectively. The relative standard deviations (RSD) < 3.3% were obtained.

A metal (Co)-organic framework-based chemiluminescence system for selective detection of L-cysteine.

A metal (Co)-Organic Framework (Co-MOF) was first found to catalyze the chemiluminescence (CL) of luminol. On the basis of X-ray photoelectron spectroscopy, powder X-ray diffraction, CL spectral, UV-visible absorption spectral, and electron spin resonance (ESR) spectral studies, as well as the research of the influence of various free radical scavengers, a possible CL mechanism was proposed. The enhanced CL might be attributed to the formation of a peroxide analogous complex between the oxygen-related radicals and the active metal site of the Co-MOF material. The established Co-MOF-luminol CL system was successfully applied to determine L-cysteine (CySH), based on the selective and sensitive enhancing effect of CySH on this CL system. Under the optimized conditions, CySH was selectively detected in the range 0.1-10 μM with a detection limit of 18 nM. This novel CL system obviously gives impetus to the new research field of metal-organic frameworks (MOFs) in chemiluminescence.

化学发光检测光子计数的统计特性

In enhanced chemiluminescence enzyme-linked immunoassay,major parameters such as detection result,efficiency of counting and S / N ratio,are related with not only photon counting devices but also statistics process of photon pulse emission in optical luminescence system. In this article,we measured the statistics characteristics of photon pulse in enhanced luminol chemiluminescence system and theoretically analyzed the design of photon counting detection device of chemiluminescence system by its statistics characteristics of its pulse emission time. The research suggests that the photon emission pulse intervals of chemiluminescence subject to Weibull distribution.