Proposed Chemiluminescence System Research Articles

Intelligent chemiluminescent system for wash-free and ultrasensitive assay of aflatoxin B1 in coix seed and decoction pieces

Aflatoxin B1 (AFB1) is one of the most harmful mycotoxins. Convenient and reliable determination of trace AFB1 is highly desired. Herein, dual hemin labeled DNA hairpin was designed as a chemiluminescence (CL) switch and combined with aptamer of AFB1 and its partial complementary strand for homogenous assay of AFB1. Due to the judicious design of three DNA sequences and the help of nicking enzyme, the AFB1 recognition, signal transduction and recycling amplification can be implemented during one-step reaction. The whole protocol only involved the simple mixing of samples with homogeneous solution, avoiding the preparation of sophisticated solid-phase sensor and eliminating the multi-step washing and resulting errors, which provided a unique tool for on-site rapid testing. Importantly, when the operation process was simplified, the detection sensitivity can be enhanced facilely due to the enzyme recycling. Under optimal conditions, the intelligent CL system for sensing AFB1 exhibited a wide dynamic range (1.0 × 10-2 ∼ 100 ng mL−1) with a low detection limit (down to 1.5 pg mL−1), suitable for detecting trace AFB1 in complex matrix. The methodology was validated in coix seed and decoction pieces. The superiority including free of washing and separation, high sensitivity, acceptable accuracy, and greenness, showed good applicability of the proposed CL system in safety evaluation of food and medicine.

Boosting Photon Emission from the Chemiluminescence of Luminol Based on Host-Guest Recognition for the Determination of Dopamine.

Modulating the photon emission of the luminophore for boosting chemiluminescence (CL) response is very crucial for the construction of highly sensitive sensors via the introduction of functionalized materials. Herein, the integration of the emitter and coreactant accelerator into one entity is realized by simply assembling cucurbit[7]uril (CB[7]) on the surface of gold nanoparticles (AuNPs) through simple assembly via a Au-O bond. The loaded CB[7] on the AuNPs improves their catalytic capacity for the generation of hydroxyl radicals(•OH). Moreover, the host-guest recognition interaction between luminol and CB[7] enables the capture of luminol on AuNPs efficiently. Also, the intramolecular electron-transfer reaction between the luminol and •OH enables the CL response more effectively in the entity, which greatly boosts photon emission ca 100 folds compared with the individual luminol/H2O2. The host-guest recognition between luminol and CB[7] is revealed by Fourier transform infrared spectroscopy, electrochemical, and thermogravimetric characterization. Moreover, the proposed CL system is successfully used for the sensitive and selective determination of dopamine (DA) based on a synergistic quenching mechanism including the competition quenching and radical-scavenging effect from DA. The present amplified strategy by integrating recognized and amplified elements within one entity simplifies the sensing process and holds great potential for sensitive analysis based on the self-enhanced strategies.

Disordered Assembly of Donors and Acceptors on Layered Double Hydroxides for High-Efficiency Chemiluminescence Resonance Energy Transfer.

High-efficiency chemiluminescence (CL) resonance energy transfer (CRET) can be obtained by shortening the donor-acceptor distance and/or improving the luminescence efficiency of CRET acceptors. However, careful design and stringent experimental conditions are usually required for the ordered assembly of CRET acceptors on support materials to avoid aggregation-caused quenching problems. In this work, an aggregation-induced emission (AIE)-active fluorophore was disorderly adsorbed on the surface of layered double hydroxides (LDHs), which could exhibit high-efficiency luminescence. On the other hand, the positively charged LDHs can further adsorb peroxynitrite (ONOO-) on the surface of LDHs. Therefore, the LDH-supported AIE fluorophore could dramatically amplify weak CL signals from ONOO- donors as a result of ultra-high CRET efficiency by coupling the shorter donor-acceptor distance with efficient CRET acceptors. The proposed CL system has been successfully applied for the detection of NaNO2 in the concentration range from 1.0 to 100 μM with a detection limit as low as 0.5 μM. Satisfactory recoveries (98-106%) and good accuracy were achieved for sausage samples. Our success will open new avenues for the convenient design of high-efficiency CRET systems.

Chemiluminescence of the Ce(IV)/CDP-Star System Based on the Phosphatase-like Activity of Ce(IV) Ions.

The phosphatase-like activity of Ce(IV) ions was applied for chemiluminescence (CL) analysis for the first time. Ce(IV) can catalyze the hydrolysis of CDP-star, which is a phosphatase substrate, to produce strong CL emission. The CL performance of the Ce(IV)/CDP-star system can be significantly improved by the addition of ionic liquids. In the presence of 1-butyl-3-methylimidazolium tetrafluoroborate, the selective and sensitive CL detection of Ce(IV) ions was achieved with a detection limit of 460 nM. The proposed CL system was also used for the detection of ascorbic acid and ClO–. It is based on the phenomenon that Ce(IV) can catalyze the hydrolysis of CDP-star, while Ce(III) cannot. The introduction of reductive ascorbic acid into the mixture of Ce(IV)/CDP-star can turn off the CL signal, while the addition of oxidative ClO– into the solution of Ce(III)/CDP-star can turn on the CL emission. Finally, Ce(IV)/CDP-star CL was successfully applied for evaluating the total antioxidant capacity in commercial fruit juice samples.

Intensive and Persistent Chemiluminescence System Based on Nano-/Bioenzymes with Local Tandem Catalysis and Surface Diffusion.

A chemiluminescence (CL) system with long persistent and intensive emission is essential for accurate CL quantitative analysis and imaging assay. However, with most known CL systems being flash-type, it is still a great challenge to develop long-lasting CL systems. Here, by combining an iron porphyrin metal-organic frameworks (FePorMOFs) based peroxidase mimic with natural glucose oxidase (GOx), an intensive and persistent CL system is presented on the basis of local tandem catalysis and surface diffusion of the nano-/bioenzymes (FePorMOF/GOx). FePorMOF synthesized by iron porphyrin linker and zirconium ion node possesses high peroxidase catalytic activity and stability. Using luminol and glucose as substrate, the FePorMOF/GOx CL system can produce intensive CL emission containing a plateau period of 7.5 h. The strong CL signal is due to the local tandem generation and reaction of H2O2 by GOx and FePorMOF, which avoids the diffusion-limited kinetics and leads to a high catalytic efficiency of the nano-/bioenzymes. On the other hand, the long persistent CL emission is attributed mainly to the enzymatic reaction-controlled H2O2 supply and surface diffusion-controlled CL reaction. The proposed CL system is explored for CL imaging sensing of glucose and homogeneous immunoassay of α-fetoprotein. The nano-/bioenzymes CL system exhibits intensive and long constant CL emission in physiological condition, showing promising applications in real-time bioassay and bioimaging.

Copper nanoclusters-enhanced chemiluminescence for folic acid and nitrite detection.

The reaction between diperiodatoargentate(III) (DPA) and folic acid (FA) produced weak chemiluminescence (CL) in acid medium, which was greatly enhanced in the presence of copper nanoclusters (CuNCs). The CL intensity of CuNCs-DPA-FA system increased with the concentration of FA ranging from 0.1 to 10.0 μM. The proposed CL system was applied for the detection of FA in pharmaceutical formulation and human urine samples. Further, the CL signal of CuNCs-DPA-FA system was inhibited by nitrite, and the inhibited CL intensity was proportional to the nitrite concentration in the range of 1.0-80.0 μM. The method was successfully applied to determine nitrite in water, pickled vegetable and sausage samples. A possible CL mechanism was briefly discussed.

Ultrasensitive determination of ascorbic acid by using cobalt oxyhydroxide nanosheets to enhance the chemiluminescence of the luminol-H2O2 system.

Ascorbic acid (AA) as an essential vitamin in the human body participates in various physiological reactions and plays a key role in many biochemical processes. Therefore, it is of vital importance to monitor and quantify AA in commercial tablets, beverages and food. In this work, a rapid and ultrasensitive chemiluminescence (CL) system for the detection of AA was developed, in which ultrathin cobalt oxyhydroxide (CoOOH) nanosheets were applied in the conventional luminol–H2O2 CL system. The results showed that ultrathin CoOOH nanosheets as a catalyzer remarkably improved the CL intensity of the CoOOH–luminol–H2O2 system, up to about 1400-fold. Under the optimized conditions, the CL inhibition efficiencies increase linearly with the concentrations of AA in the range of 1–500 pmol L−1, and the limit of detection was 39 fmol L−1. Moreover, the proposed CL system was successfully applied in the determination of AA in medicinal tablets with satisfactory results.

Chemiluminescence of graphene quantum dots induced by acidic potassium permanganate and its application to quenchometric flow-injection assays of hydroquinone in water

Graphene quantum dots (GQDs) with particle size of 4.5±1.0nm were prepared and characterized by transmission electron microscopy, UV–vis absorption spectroscopy and fluorescence spectroscopy. It was found that KMnO4 could oxidize GQDs to produce a relatively intense chemiluminescence (CL) emission. The mechanism of CL generation was investigated based on absorption spectra and CL emission spectra. CL emission was attributed to the radiative recombination of oxidant-injected holes and thermally excited electrons in the GQDs. On the other hand, both KMnO4 and ∙O2− could react with GQDs to produce GQDs∙+ and GQDs∙−. The electron-transfer annihilation of GQDs∙+ and GQDs∙− could form excited-state GQDs*, which acted as the final emitter in the system. In order to show the analytic potential of GQDs–KMnO4 CL system, it was applied for the determination of hydroquinone based on its diminishing effect. Under the optimized conditions, the proposed CL system exhibits excellent analytic performance for determination of hydroquinone. Calibration curve in the range of 2.49×10−4–9.96×10−7gmL−1 was linear with the correlation coefficient (r) of 0.9924. The limit of detection was 8.46×10−8gmL−1, and the relative standard deviation (RSD) was found to be 1.7% for 11 determinations of 4.98×10−6gmL−1 hydroquinone. The applicability of the method was verified by applying to real tap water, lake water, and waste water samples. The recoveries were in the range of 89.7–97.1% with RSD of 0.9–2.1%. The proposed method has a good linearity, high sensitivity and good repeatability and can be applied for routine determination of hydroquinone in water.

Comparison of two methods for selegiline determination: A flow-injection chemiluminescence method using cadmium sulfide quantum dots and corona discharge ion mobility spectrometry

Two analytical approaches including chemiluminescence (CL) and corona discharge ionization ion mobility spectrometry (CD-IMS) were developed for sensitive determination of selegiline (SG). We found that the CL intensity of the KMnO4–Na2S2O3 CL system was significantly enhanced in the presence of l-cysteine capped CdS quantum dots (QDs). A possible CL mechanism for this CL reaction is proposed. In the presence of SG, the enhanced CL system was inhibited. Based on this inhibition, a simple and sensitive flow-injection CL method was proposed for the determination of SG. Under optimum experimental conditions, the decreased CL intensity was proportional to SG concentration in the range of 0.01 to 30.0mgL−1. The detection limit (3σ) was 0.004mgL−1. Also, SG was determined using CD-IMS, and under optimum conditions of CD-IMS, calibration curves were linear in the range of 0.15 to 42.0mgL−1, with a detection limit (3σ) of 0.03mgL−1. The precision of the two methods was calculated by analyzing samples containing 5.0mgL−1 of SG (n=11). The relative standard deviations (RSDs%) of the flow-injection CL and CD-IMS methods are 2.17% and 3.83%, respectively. The proposed CL system exhibits a higher sensitivity and precision than the CD-IMS method for the determination of SG.

Determination of dexamethasone by flow-injection chemiluminescence method using capped CdS quantum dots

l-Cysteine capped CdS quantum dots (QDs) were synthesized through a facile hydrothermal method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence (PL) and UV–Vis spectroscopy. The light emitted from KMnO4–l-cysteine capped CdS QDs reaction in acidic medium was applied as a simple and sensitive chemiluminescence (CL) system for determination of dexamethasone. The CL intensity of KMnO4–l-cysteine capped CdS QDs CL system was remarkably enhanced in the presence of dexamethasone. Under optimum experimental conditions, the enhanced CL intensity was related to dexamethasone concentration in the range of 0.004–25.0mgL−1, with the detection limit (3σ) of 0.0013mgL−1. The analytical applicability of the proposed CL system was assessed by determining dexamethasone in spiked environmental water samples and pharmaceutical formulation. The analytical performances of proposed flow-injection CL method for the determination of dexamethasone were compared with those obtained by corona discharge ionization ion mobility spectrometry (CD-IMS) method. The proposed CL system exhibits a higher sensitivity and precision than the CD-IMS method for the determination of dexamethasone.

A novel flow-injection chemiluminescence method for determination of baclofen using l-cysteine capped CdS quantum dots

l-Cysteine capped CdS quantum dots (QDs) were synthesized through a facile hydrothermal method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), photoluminescence (PL), and UV–vis spectroscopy. The l-cysteine capped CdS QDs sample displayed chemiluminescence (CL) emission in reaction with KMnO4 in acidic medium. It was found that the CL intensity of KMnO4–l-cysteine capped CdS QDs CL system was remarkably enhanced in the presence of Na2S2O3. Furthermore, the possible CL mechanism was presented for this CL reaction according to results of the kinetic curves of CL systems, the spectra of CL, PL and UV–vis. The CL intensity of KMnO4–l-cysteine capped CdS QDs–Na2S2O3 was strongly inhibited in the presence of baclofen. Based on this inhibition, a novel and sensitive flow-injection CL method was developed for the determination of baclofen. Under optimum conditions, the CL intensity was inversely proportional to the concentration of baclofen in the range of 0.012–24.0mgL−1, with a detection limit (3σ) of 0.0035mgL−1. The analytical applicability of the proposed CL system was assessed by determining baclofen in spiked environmental water samples and pharmaceutical formulation. The analytical performances of proposed flow-injection CL method for the determination of baclofen were compared with those obtained by corona discharge ionization ion mobility spectrometry (CD-IMS) method. The proposed CL system had a higher sensitivity than the CD-IMS method for the determination of baclofen.

Chemiluminescence of graphene quantum dots and its application to the determination of uric acid

We report on the chemiluminescence (CL) of graphene quantum dots (GQDs) induced by direct chemical oxidation. GQDs were prepared by a simple carbonization method and characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy and Raman spectroscopy. It was found that Ce(IV) could oxidize GQDs to produce a relatively intense CL emission. The mechanism of CL generation was investigated based on the fluorescence and CL emission spectra. It was attributed to the radiative recombination of oxidant-injected holes and thermally excited electrons in the GQDs. In order to show the analytical application potential of GQDs-Ce(IV) CL system, it was applied to the determination of uric acid. Under the optimized conditions, the proposed CL system exhibited excellent analytical performance for determination of uric acid in the range of 1.0×10−6M–5.0×10−4M with a limit of detection of 5.0×10−7M. The method was applied to the determination of uric acid in human plasma and urine samples, with satisfactory results.

Enhanced chemiluminescence of the luminol–KMnO4 system by CuO nanosheets and its application for determination of meropenem in water and human serum

CuO nanosheets were synthesized by an easy and green sonochemical method. It was found that, CuO nanosheets could significantly catalyze the chemiluminescence (CL) reaction of luminol–KMnO4 in an alkaline condition. Based on this finding, a new CL system (luminol–KMnO4–CuO nanosheets) combined with flow injection analysis has been developed for the determination of meropenem for the first time. Moreover, the CL intensity was enhanced when meropenem was presented in the reaction system. Under the optimum conditions, the enhanced CL intensity was proportional to the concentration of meropenem in the ranges of 0.005–6.00mgL−1, with a detection limit (3σ) of 0.0036mgL−1. The precision of the method was calculated by analyzing samples containing 1.0mgL−1 meropenem (n=11) and the relative standard deviation (RSD) was 1.7%. Also, a total analysis time per sample was 30s which confirmed the rapidity of the proposed assay. The practicality of the proposed CL system was evaluated by determining meropenem in spiked environmental water samples and human serum. A discussion on the possible CL reaction mechanism was also presented.

High selectivity sensing of cobalt in HepG2 cells based on necklace model microenvironment-modulated carbon dot-improved chemiluminescence in Fenton-like system

In this work, based on electronic spinning resonance and chemiluminescence (CL) measurements, it is found that the reaction kinetics of Co(II)-triggered Fenton-like reaction is much faster than those of other transition metal ions, which facilitates the observation of the strong CL signals from Co(II). Utilizing the polymer–surfactant complexes (i.e., necklace model) to act as a novel CL microenvironment, a highly selective CL sensing system for the detection of Co(II) has been successfully fabricated based on the CL resonance energy transfer between the Fenton-like reaction and necklace model microenvironment-modulated carbon dots. Under optimized experimental conditions, this proposed CL system exhibits a stable response to Co(II) over a concentration range from 1.0 to 1000nM with a detection limit as low as 0.67nM. Finally, this system has been successfully used for the detection of Co(II) in HepG2 cells, and the results were agreed with those obtained by inductively coupled plasma mass spectrometry (ICP-MS) method.

Chemiluminescence microfluidic system of gold nanoparticles enhanced luminol-silver nitrate for the determination of vitamin B12

A rapid and sensitive chemiluminescence (CL) system coupled with a microfluidic chip has been presented to determine vitamin B12 (VB12) based on the reaction of luminol and silver nitrate (AgNO(3)) in the presence of gold nanoparticles (AuNPs). A microfluidic chip was fabricated by a soft-lithographic procedure using polydimethyl siloxane (PDMS) having four inlets and one outlet with a 200μm wide, 250μm deep, and 100mm long microchannel. Ag(+) was used as a chemiluminogenic oxidant in this CL reaction which oxidized luminol to produce strong CL signal in the presence of AuNPs. Luminol reacted with AgNO(3) under the catalysis of AuNPs to produce luminol radicals which reacted with dissolved oxygen and emitted CL light. The proposed CL system was applied to determine the amount of VB12 in VB12 tablets and multivitamin. Under the optimum conditions, the CL intensity of the system was increased with the concentration of VB12 in the range of 0.25-100ng mL(-1) with the correlation coefficient of 0.9982. The limit of detection was found to be 0.04ng mL(-1) with the relative standard deviation of 1.56% for five replicate determinations of 25ng mL(-1) of VB12. The CL reaction mechanism was demonstrated by UV-visible spectra and CL emission spectra.

Flow-Injection Chemiluminescence Determination of Fleroxacin in Pharmaceutical Preparations and Human Urine

Quality control of drug fleroxacin dosage, its monitoring in biological fluids, and research of drug’s metabolism and action are an important analytical task. A new chemiluminescence (CL) reaction system was established for the determination of fleroxacin (FLX). The trivalence dysprosium-sensitized CL emission mechanism was investigated by comparing the fluorescence emission with CL spectra. The CL spectra of FLX-KMnO 4 -Na 2 S 2 O 3 -H 6 P 4 O 13 system are from the narrow characteristic emission of Dy 3+ at 482 and 578 nm ( 4 F 9 → 6 H 15/2 , 4 F 9 → 6 H 13/2 ) through the energy transfer from the excited SO 2 * to analyte, followed by intramolecular energy transfer from analyte* to Dy 3+ . The optimum conditions for CL emission were investigated and optimized. The relationships between the relative CL intensity and the concentration of the studied analyte have good linearity. The detection limit for FLX was 3.0×10 -10 g/mL. The relative standard deviation is 2.0% for 11 determinations of FLX at 2.0×10 -6 g/mL. The proposed CL system has been successfully applied for the determination of FLX in the injections and urine sample with satisfactory result. .

Determination of phenolic compounds and their antioxidant activity in Erigeron acris L. extracts and pharmaceutical formulation by flow injection analysis with inhibited chemiluminescent detection

It was found that the chemiluminescence (CL) produced from the reaction of luminol with iodine in the alkaline medium was strongly inhibited by plant phenolic compounds. Based on this finding, a new flow injection CL method was developed for the determination of caffeic acid and 6′-caffeoylerigeroside. The latter compound was isolated for the first time from Erigeron acris L. herb. The method was simple, rapid and sensitive with a detection limit of 4 × 10 −3 ng mL −1 (caffeic acid) and 0.18 ng mL −1 (6′-caffeoylerigeroside), linear range of 0.1–1.5 ng mL −1 (caffeic acid) and 1–200 ng mL −1 (6′-caffeoylerigeroside), relative standard deviation of 3.3% for 10 measurements of 0.45 ng mL −1 caffeic acid and 2.9% for 40 ng mL −1 6′-caffeoylerigeroside. This method was successfully applied to determine the content of phenolic compounds/antioxidant activity of E. acris L. extracts and phenolic acids content in pharmaceutical formulation. A possible mechanism of the inhibition of the proposed CL system was discussed.

SO 32−-based chemiluminescence in unbuffered solution with ClO 2 as oxidant and its analytical application

In this paper, SO 3 2−-chemiluminescence (CL) system in unbuffered solution with ClO 2 as oxidant is proposed. ClO 2 could oxidize sulfite in unbuffered solution to produce CL emission, and riboflavin could sensitize the ClO 2–SO 3 2−-based CL system. The ClO 2–SO 3 2−–riboflavin CL reaction was chosen as a model system and explored the possibility of SO 3 2−-based CL system in unbuffered solution. Compared with the reported SO 3 2−-based CL system in strong acid media, the proposed CL system owns its advantages. Combined with flow-injection analysis, the proposed CL system was applied to measurement of riboflavin in pharmaceuticals.

Flow injection chemiluminescence analysis of phenolic compounds using the NCS-luminol system

A flow injection system coupled with two simple and sensitive chemiluminescence (CL) methods is described for the determination of some phenolic compounds. The methods are based on the inhibition effects of the investigated phenols on the CL signal intensities of N-chlorosuccinimide-KI-luminol (NCS-KI-luminol) and NCS-luminol systems. The influences of the chemical and hydrodynamic parameters on the decrease in CL signal intensities of NCS-KI-luminol and NCS-luminol systems for hydroquinone, catechol, and resorcinol, serving as the model compounds of analyte, were studied in the flow injection mode of analysis. Under the selected conditions, the proposed CL systems were used for the determination of some phenolic compound and analytical characteristics of the systems including calibration equation, correlation coefficient, linear dynamic range, limit of detection, and sample throughput. The limits of detection for hydroquinone, catechol, and resorcinol were 0.002, 0.01, and 0.3 microM using the NCS-KI-luminol system; for the NCS-luminol system these were 0.01, 0.17, and 1.6 microM, respectively. The relative standard deviation for 10 repeated measurements of 0.04, 0.06, and 1 microM of hydroquinone, catechol, and resorcinol were 1.9, 1.4, and 2.0%, respectively, with the NCS-KI-luminol system; for 0.2, 0.5, and 4 microM of hydroquinone, catechol, and resorcinol these were 2.6, 2.2, and 3.7%, respectively, using the NCS-luminol system. The method was applied to the determination of catechol in known environmental water samples with a relative error of less than 6%. A possible reaction mechanism of the proposed CL system is discussed briefly.

Homogeneous chemiluminescence system in neutral and near neutral aqueous solution with ClO 2 as oxidant and its analytical application

Using ClO 2 as chemiluminescence (CL) oxidant, a novel homogeneous CL system in neutral and near neutral aqueous solution is proposed in this paper. ClO 2 could oxidize sulfite in pH 5.0–8.5 acetate buffer to produce CL emission, and pipemidic acid could sensitize the CL system. The ClO 2–SO 3 2−–pipemidic acid reaction was used as a model CL system and explored the possibility of highly active and eco-friendly ClO 2 being used as CL oxidant in neutral and near neutral aqueous solution. Combined with flow-injection analysis, the proposed CL system was applied to the automated dissolution testing of pipemidic acid tablet. Compared with the common strong acidic or strong basic CL system, this proposed CL owns its advantages.