Chemiluminescence Reagent Research Articles

A cationic iridium(III) complex containing a thiosemicarbazide unit: Synthesis and application for turn-on chemiluminescent detection of Hg2+

A novel cationic iridium(III) complex [(ppy)2Ir(bPCPC)]PF6 (ppy: 2-phenylpyridine; bPCPC: 2-([2,2′-bipyridine]-4-carbonyl)-N-phenylhydrazinecarbothioamide) containing a thiosemicarbazide unit was designed and synthesized. The thiosemicarbazide unit was a sensitive functional group to Hg2+, when it reacted with Hg2+, it was desulphurized and thus led to the formation of 1,3,4-oxadiazole, [(ppy)2Ir(bPCPC)]PF6 resultantly was used as a “turn-on” chemodosimeter for luminescent detection of Hg2+ in DMF/PBS buffer solution at pH = 7–11. Except for Ag+, recognition capability of [(ppy)2Ir(bPCPC)]PF6 to Hg2+ was not interfered by other common metal ions (Co2+, Li+, Zn2+, Pb2+, K+, Al3+, Na+, Mn2+, Cu2+, Fe2+, Fe3+, Cr3+, Ba2+, Mg2+, Ni2+ and Ca2+). The detection limit was 1.83 × 10−9 mol∙L−1 (0.37 ppb), which indicated the complex was a highly sensitive chemiluminescent detection reagent of Hg2+.

A handheld 3D-printed microchip for simple integration of the H2O2-producing enzymatic reactions with subsequent chemiluminescence detection: Application for sugars

Herein, a novel lab-on-a-chip (LoC) device fabricated by 3D printing based on H2O2-producing enzymatic reactions with sensitive chemiluminescence (CL) detection was developed to measure different sugars, including glucose, fructose, sucrose, and maltose, in honey, juice, and rice flour samples. The pumpless microchip included two main parts, separated by new cone-shape blocking valves; part A for sample introduction and subsequent enzymatic reaction, besides the CL reagent (luminol) container, and part B for detection. The specific enzyme(s) were embedded into the pores of the zinc zeolite-imidazole framework (ZIF-8) to improve their storage stability. By opening the valves, H2O2 produced by enzymatic reaction and luminol could flow through the designed channels into the detection zone on part B, where a 2D cobalt-imidazole framework was embedded to improve the luminol-H2O2 CL emission. The obtained signal was proportional to the considered sugar concentration, with the detection limits range of 20–268 µM.

Chemiluminescent Two-Dimensional Metal-Organic Framework with Multiple Metal Catalytic Centers and Its Peroxidase-like Activity for Sensing of Small Molecules.

Two-dimensional (2D) porphyrin-based metal-organic frameworks (MOFs) hold great promise in a variety of areas with the merits of large lateral size and abundant functional groups. The chemiluminescent 2D MOF has rarely been reported. In this work, a chemiluminescence (CL) reagent and noble metal nanoparticle dual-functionalized 2D MOF (ABEI/AuNPs/CuTCPP) was developed through the surfactant-assisted and in situ synthetic growth method, exhibiting strong and stable CL property and outstanding peroxidase-mimicking activity. The special nanostructure of ABEI/AuNPs/CuTCPP endowed it with multi-catalytic routes in the CL reaction, which showed a unique pH-regulated and time-resolved CL kinetic curve. A CL mechanism with multi-catalytic centers has been proposed. AuNPs participated in the fast catalytic process and CuTCPP in the slow and strong catalytic reaction. Owing to the impressive structural features and intrinsic enzymatic tandem reaction from natural enzyme to artificial enzyme, a model biosensor was designed for the detection of small metabolic molecules. Employing choline as a model target, the proposed biosensor showed a highly sensitive response to choline in the linear range from 0.3 to 300 μM with a detection limit of 82.6 nM. Significantly, the strategy may be generalized to the monitoring of other biologically important compounds involved in the production of H2O2.

Announcement of the 2022 winners of the Spychala and Women in Science Awards

Announcement of the 2022 winners of the Spychala and Women in Science Awards

Smartphone-Based Chemiluminescent Origami µPAD for the Rapid Assessment of Glucose Blood Levels.

Microfluidic paper analytical devices (µPADs) represent one of the most appealing trends in the development of simple and inexpensive analytical systems for diagnostic applications at the point of care (POC). Herein, we describe a smartphone-based origami µPAD for the quantitative determination of glucose in blood samples based on the glucose oxidase-catalyzed oxidation of glucose leading to hydrogen peroxide, which is then detected by means of the luminol/hexacyanoferrate(III) chemiluminescent (CL) system. By exploiting the foldable µPAD format, a two-step analytical procedure has been implemented. First, the diluted blood sample was added, and hydrogen peroxide was accumulated, then the biosensor was folded, and a transport buffer was added to bring hydrogen peroxide in contact with CL reagents, thus promoting the CL reaction. To enable POC applicability, the reagents required for the assay were preloaded in the µPAD so that no chemicals handling was required, and a 3D-printed portable device was developed for measuring the CL emission using the smartphone’s CMOS camera. The µPAD was stable for 30-day storage at room temperature and the assay, displaying a limit of detection of 10 µmol L−1, proved able to identify both hypoglycemic and hyperglycemic blood samples in less than 20 min.

Next generation luminol derivative as powerful benchmark probe for chemiluminescence assays

Chemiluminescence (CL) provides outstanding analytical performance due to its independence from external light sources, background-free nature and exceptional sensitivity and selectivity. Yet, ultra-sensitive (bio)analysis is impeded by low hydrophilicity, poor quantum yields, fast kinetics or instability of most CL reagents such as luminol, acridinium esters, dioxetanes or peroxyoxalic derivatives. Photophysical studies show that m-carboxy luminol overcomes these limitations as its hydrophilic design provides a 5-fold increase in relative quantum yield resulting in superior performance in H2O2-dependent bioassays with 18-fold higher sensitivity for the quantification of its co-reactant H2O2, and 5-times lower detection limits for the luminophore. Studies with CL enhancers suggest its significance for mechanistic investigations in tandem with peroxidases. Finally, its integration into enzymatic and immunoassay applications demonstrates that m-carboxy luminol will provide signal enhancement, lower detection limits, and increased dynamic ranges for any other luminol-based CL assay, thus comprising the potential to replace luminol as benchmark probe.

A High Selective Chemiluminescent Probe Derived fromIso‐luminol Enabling High Sensitive Determination of Ferrous Ions in the Environmental Waters

Main observation and conclusionA new chemiluminescence (CL) reagent named 4‐amino‐5‐thiocyanato‐phthalyl‐hydrazine (iso‐luminol‐SCN) is synthesized by the bromide‐mediated substitution reaction ofiso‐luminol with sodium thiocyanate in dimethyl formamide (DMF) at room temperature. Strong CL is observed foriso‐luminol‐SCN oxidized by hydrogen peroxide (H2O2) in the presence of Fe2+, with the CL intensity strongly depending on the concentration of Fe2+and being hardly interferred by other common metal ions. Based on this fact, a flow injection CL method is established for the high sensitive and selective determination of Fe2+. The CL intensity was linearly correlated with the concentration of Fe2+in the range of 1.0 × 10–8mol·L–1to 1.0 × 10–5mol·L–1following the equation CLnet= 166.3c+ 57.7 (c, ×10–6mol·L–1;n= 7;R2= 0.9988). The detection limit is calculated to be 3.2 × 10–9mol·L–1Fe2+based on the 3S0/K principle. The relative standard deviation (RSD) was 3.7% for 1.0 × 10–6mol·L–1Fe2+(n= 11), a support for the precision of Fe2+measurement. The recoveries of Fe2+were obtained in the range of 98.8%—101.6% in three real water samples, showing the applicability and reliability by the proposed method. The possible CL mechanism is proposed based on the kinetic characteristic of the CL reaction and the CL spectrum.

On paper synthesis of metal-organic framework as a chemiluminescence enhancer for estimating the total phenolic content of food samples using a smartphone readout

Herein, a novel paper-based chemiluminescence (CL) assay is reported using a smartphone readout for on-site and reliable analytical applications. The CL system was based on the high-performance improving effect of cobalt-imidazole metal-organic framework (CoMOF) on luminol-hydrogen peroxide (H2O2) CL emission. The CoMOF was grown on paper and used as a support for the CL reaction, which led to an intense CL emission and good reproducibility. More importantly, the stability of luminol, as the CL reagent, was greatly improved in the presence of CoMOF. This high stability, along with the high-yield CL emission, makes the device highly suitable for commercialization. Furthermore, using a smartphone as the detector for the developed device made the process easier and more accessible for public usage. In this work, the new paper-based CL smartphone device was used for the detection of the total phenolic content of food samples. Phenolic compounds (PC) are hydroxyl radical scavengers that can effectively quench the CL emission of the luminol–H2O2–CoMOF system. After optimizing the reaction conditions, the system could detect PC at the μg mL−1 level. Detection limits of 0.12, 0.28, 0.46, 0.85, and 1.23 μg mL−1 were obtained for gallic acid, quercetin, catechin, kaempferol, and caffeic acid, respectively. This work is the first report on the practical application of smartphone CL assays for the estimation of PC. The proposed assay is an easy-to-use, low-cost, portable, and suitable assay for on-site screening purposes.

Cobalt-imidazole metal-organic framework loaded with luminol for paper-based chemiluminescence detection of catechol with use of a smartphone.

Chemiluminescence (CL) reagent luminol was loaded into the porous structure of cobalt-imidazole metal-organic framework (MOF) ZIF-67 to obtain luminol-functionalized ZIF-67 (luminol@ZIF-67) with CL property. The morphology, composition, CL property, and CL mechanism of luminol@ZIF-67 were carefully investigated. The obtained luminol@ZIF-67 exhibited strong, stable, and visible CL emission that reacted with H2O2, attributed to the strong catalytic effect of ZIF-67 combined with the shortened diffusion distance between luminol and the catalytic center. The CL intensity of luminol@ZIF-67 was more than 550 times higher than that of luminol. Catechol can effectively quench the CL emission of luminol@ZIF-67 that reacted with H2O2. Then, a simple paper-based CL imaging detection method was developed for the detection of catechol by using a smartphone as a portable detector. The linear calibration curve of the developed CL assay for catechol ranged from 5 to 100mg/L with detection limit of 1.1mg/L (S/N = 3δ). The strong CL emission of luminol@ZIF-67 combined with the effective quench ability of catechol guaranteed high sensitivity of the detection method. The practical application ability of the developed CL assay was tested by the determination of catechol in tea and tap water samples, resulting in acceptable results. This work provides an effective paper-based CL detection method for catechol and enriches the species of the chemiluminescent MOF material.

An intensive and glow-type chemiluminescence of luminol-embedded, guanosine-derived hydrogel

In this paper, an intensive and glow-type chemiluminescence (CL) hydrogel was prepared by simultaneous incorporation of chemiluminescence reagent (luminol) and catalytic cofactor (hemin) into the scaffold of guanosine-derived hydrogel. The self-assembled hydrogel consisted of K+ stabilized hemin/G-quartet structures, showing significant enzyme-like activity to H2O2-mediated oxidation of luminol. After adding H2O2 into the hydrogel, blue light visible to naked eyes would come into being and last for over 8 h. The lasting-time CL emission of hydrogel was achieved due to a mechanism of slow-diffusion-controlled heterogeneous catalysis. Moreover, this self-assembled hydrogel performed a good response to H2O2 and the CL emission images could be recorded by smartphone. The hydrogel could remain excellent lifetime stability for months and the stable, enhanced and glow-type CL emission could improve the reliability and precision of CL detection, which has a promising application in cold light source and H2O2 detection of real biological samples.

Self-Illuminated, Oxygen-Supplemented Photodynamic Therapy via a Multienzyme-Mimicking Nanoconjugate.

Current photodynamic therapy (PDT) faces several intrinsic limitations, including insufficient oxygen supply and limited penetration of external light sources. Herein, we report a nanoconjugate, which, in response to the elevated hydrogen peroxide levels associated with tumor tissues, can supplement the oxygen needed for PDT and provide local self-illumination. Consisting of a MnFe2O4 core, a metal-organic framework shell loaded with the chemiluminescence reagent luminol, and a hyaluronic acid surface coating, the nanoconjugate is highly effective for suppressing cancer tissues in vivo via PDT in the absence of externally delivered light.

Multicolor Chemiluminescent Resonance Energy-Transfer System for In Vivo High-Contrast and Targeted Imaging.

Chemiluminescence (CL) resonance energy transfer (CRET) has received great attention due to its fascinating applications in in vivo imaging and photodynamic therapy. Here, we report a highly efficient CRET polymer dot (CRET-Pdots)-based system using catalytic CL reagents as energy donors and fluorescent polymers and dyes as energy acceptors. CRET-Pdots consist of Fe(III) deuteroporphyrin IX (CL catalyst), fluorescent polymers, and dyes. The CL intensity and duration are markedly enhanced by using ultrasensitive catalytic CL reaction of luminol analogue-H2O2, and the CL emission wavelength can be adjusted by one-step/two-step energy-transfer strategies. CRET-Pdots show intensive multicolor CL (about 3000× enhanced), an adjustable emission wavelength (470-720 nm), long CL duration (over 8 h), and a high CRET efficiency (50%). CRET-Pdots possess excellent biocompatibility, sensitive response to reactive oxygen species (ROS), and ultrahigh catalytic activity. They are successfully used for high-contrast real-time ROS imaging and in vivo tumor-targeted imaging with an excellent signal-to-noise ratio (over 90).

A systematic review of contamination (aerosol, splatter and droplet generation) associated with oral surgery and its relevance to COVID-19

IntroductionThe current COVID-19 pandemic caused by the SARS-CoV-2 virus has impacted the delivery of dental care globally and has led to re-evaluation of infection control standards. However, lack of clarity around what is known and unknown regarding droplet and aerosol generation in dentistry (including oral surgery and extractions), and their relative risk to patients and the dental team, necessitates a review of evidence relating to specific dental procedures. This review is part of a wider body of research exploring the evidence on bioaerosols in dentistry and involves detailed consideration of the risk of contamination in relation to oral surgery.MethodsA comprehensive search of Medline (OVID), Embase (OVID), Cochrane Central Register of Controlled Trials, Scopus, Web of Science, LILACS and ClinicalTrials.Gov was conducted using key terms and MeSH (Medical Subject Headings) words relating to the review questions. Methodological quality including sensitivity was assessed using a schema developed to measure quality aspects of studies using a traffic light system to allow inter- and intra-study overview and comparison. A narrative synthesis was conducted for assessment of the included studies and for the synthesis of results.ResultsEleven studies on oral surgery (including extractions) were included in the review. They explored microbiological (bacterial and fungal) and blood (visible and/or imperceptible) contamination at the person level (patients, operators and assistants) and/or at a wider environmental level, using settle plates, chemiluminescence reagents or air samplers; all within 1 m of the surgical site. Studies were of generally low to medium quality and highlighted an overall risk of contaminated aerosol, droplet and splatter generation during oral surgery procedures, most notably during removal of impacted teeth using rotatory handpieces. Risk of contamination and spread was increased by factors, including proximity to the operatory site, longer duration of treatment, higher procedural complexity, non-use of an extraoral evacuator and areas involving more frequent contact during treatment.ConclusionA risk of contamination (microbiological, visible and imperceptible blood) to patients, dental team members and the clinical environment is present during oral surgery procedures, including routine extractions. However, the extent of contamination has not been explored fully in relation to time and distance. Variability across studies with regards to the analysis methods used and outcome measures makes it difficult to draw robust conclusions. Further studies with improved methodologies, including higher test sensitivity and consideration of viruses, are required to validate these findings.

Industry Development of Derivative Functionalized Gold Nanomaterials and Their Application in Chemiluminescence Bioanalysis: Based on the Industrial Practice of China's Central Yunnan Urban Agglomeration

Electrochemiluminescence biosensor is an analytical method combining electrochemiluminescence technology with biosensor. Using nanomaterials as electrochemical luminescence sensor platform can not only immobilize a large number of biomolecules but also improve the performance of the sensor to realize the supersensitive detection of biomacromolecules. Although these methods have high sensitivity for bioanalysis, there are still some shortcomings which limit the practical application. Therefore, this paper discusses the development of functional gold nanomaterials industry and its application in chemiluminescence bioanalysis. In this paper, two methods of synthesizing luminescent functional gold nanomaterials at room temperature were studied by using chemiluminescent reagents as reducing agent and protective agent. Based on luminescent functionalized gold nanoparticles, immunoassay and DNA bioanalysis probes were constructed, and their applications in chemiluminescence and electrochemiluminescence bioanalysis were discussed. Finally, the simulation results show that the relative deviation between the experimental results and the existing clinical methods is less than 17%. The sensor has good stability and selectivity and can be used for the determination of CEA in human serum. The gold nanomaterials synthesized by further research have excellent chemiluminescence activity and can be used to label biomolecules and prepare biological probes. This article aims to explore the application of chemical methods in the transformation of new industries, to achieve breakthroughs in new products in industrial innovation, and to achieve the cross-fusion of management science and engineering disciplines and chemical disciplines. The industrial development of derivative functionalized gold nanomaterials has broad application prospects in biological analysis.

Chemoselective reaction of bifunctional carboxysulfonic acid systems: Preparation of useful intermediates for chemiluminescent, fluorescent and UV absorbing bifunctional linkers

Heterobifunctional compounds are of considerable interest in convergent synthesis strategies as well as in the labeling/tagging of biological molecules. Herein is described a synthetic strategy to functionalize sulfonic acids in the presence of carboxylic acids without the need for protection/deprotection steps. Bifunctional carboxysulfonic acids are transformed under mild conditions to the corresponding carboxysulfonyl fluorides which are reacted with the amine of choice to provide sulfonamides. The carboxylic acid remains free and is available for subsequent activation and further chemical elaboration. The generality of this approach is demonstrated herein, and an example of utility is outlined in which carboxysulfonyl-containing chemiluminescent reagents are transformed into unique red-shifted chemiluminescent reagents.

Analytical Applications of Permanganate as an Oxidant in the Determination of Pharmaceuticals Using Chemiluminescence and Spectrophotometry: A Review

Background: Potassium permanganate is a green and versatile industrial oxidizing agent. Due to its high oxidizing ability, it has received considerable attention and has been extensively used for many years for the synthesis, identification, and determination of inorganic and organic compounds. Objective: Potassium permanganate is one of the most applicable oxidants, which has been applied in a number of processes in several industries. Furthermore, it has been widely used in analytical pharmacy to develop analytical methods for pharmaceutically active compounds using chemiluminescence and spectrophotometric techniques. Results: This review covers the importance of potassium permanganate over other common oxidants used in pharmaceuticals and reported its extensive use and analytical applications using direct, indirect and kinetic spectrophotometric methods in different pharmaceutical formulations and biological samples. Chemiluminescent applications of potassium permanganate in the analyses of pharmaceuticals using flow and sequential injection techniques are also discussed. Conclusion: This review summarizes the extensive use of potassium permanganate as a chromogenic and chemiluminescent reagent in the analyses of pharmaceutically active compounds to develop spectrophotometric and chemiluminescence methods since 2000.

A highly sensitive chemiluminescence assay for diniconazole by using CuInS2 quantum dots

We demonstrate here the first use of water-soluble copper indium sulfide quantum dots (CuInS2 QDs) as the chemiluminescence (CL) reagent and its application to the highly sensitive detection of diniconazole. We utilized a hydrothermal method for synthesis of mercaptopropionic acid-capped CuInS2 QDs, which were characterized by TEM image, EDS, and XRD pattern. The performance of these QDs as the CL reagent was investigated by using several oxidizing agents and found that acidic potassium permanganate (KMnO4) gave the highest CL signal. CuInS2 QDs/KMnO4 as a novel CL probe was then used for assay of diniconazole based on its unique enhancing effect. In the optimum settings, a linear calibration plot was obtained for diniconazole in the concentration range of 4.0 × 10−9 mol L−1–1.5 × 10−6 mol L−1, with a limit of detection of 1.0 × 10−9 mol L−1. The study of interferences and recoveries confirmed the suitability of the method for assay of environmental water samples.

Determination of Phenolic Acids in Botanical Pharmaceutical Products by Capillary Electrophoresis with Chemiluminescence Detection

A rapid and simple method was developed to determine the phenolic acids ferulic acid, chlorogenic acid and salicylic acid in botanical drugs by capillary electrophoresis with chemiluminescence detection. The sensitive chemiluminescence detection was carried out in a laboratory-constructed temperature-controlled interface by the use of acidic potassium permanganate as a chemiluminescence reagent. To obtain the optimized conditions, the experimental conditions for the capillary electrophoresis separation and chemiluminescence detection were systematically examined. Under the optimized conditions, the analytes were well separated within 7 min. The limits of detection for ferulic acid, chlorogenic acid and salicylic acid were 35, 58 and 37 µg/mL and the limits of quantification were 117, 193 and 123 µg/mL, respectively. The proposed method was successfully applied for the quantitative determination of phenolic acids in Lonicera japonica flos and Rhizoma Chuanxiong.

Ultrasensitive 3D Printed Immunoarrays for Protein Detection Down to Single Cell Levels

Accurate, sensitive measurements of proteins are crucial for modern biomedical research, with applications in basic research, medical diagnostics, therapy guidance, and drug development. Fast, selective, low cost detection of multiple proteins is important for public health and a key component of future personalized medicine. There are >50,000 gene product proteins (omitting post-translational modifications and IgGs) in human plasma, and large subsets in serum, urine, and saliva. However, techniques such as LC-MS/MS, immunoassays and protein counting can reliably detect <2000 of these proteins and are quite expensive. This paper addresses the challenge to develop low cost, automated 3D-printed immunoarrays for liquid protein samples and cells with LODs <0.1 fg/mL. We have developed prototype multiplexed microfluidic immunoarrays with sensitivity better than protein counting applicable to plasma, serum, saliva, urine, cell lysates and cell cultures. Protein detection at the single cell level was also achieved.Unique detection features including nanostructured sensing, array design, and protocol optimization provide large decreases in LODs and greatly enhanced sensitivities. Our prototypes are based on chemiluminescence (CL) and amperometric detection. Our CL array achieved LODs of 0.1 fg/mL for membrane protein DSG3, as well as VEGF-C and VEGF-D in conditioned media of cell cultures. This LOD is 0.8 zeptomolar, or ~100 molecules of DSG3 in 90 mL and results from 30 trillion capture antibodies (Ab1) in array detection cylinders using an ultrabright femto-luminol CL reagent activated by H2O2 and poly-(horseradish peroxidase) (poly-HRP, 400 HRPs/molecule). Femto-luminol combined with poly-HRP provides very high CL signal amplification and S/N using the 400 HPR polymer.Proteins are also efficiently captured in detection cylinders with 30 trillion antibodies, combined with the ultrabright CL reagent and rigorous protocol optimization to prove unprecedented LODs. Microprocessor automation can achieve fast multiplexed assays with these immunoarrays at <$0.50/protein. We are also exploring ultra-high sensitivity amperometric detection in these systems with similar sensitivity enhancement principles.

Efficient Cascade Resonance Energy Transfer in Dynamic Nanoassembly for Intensive and Long-Lasting Multicolor Chemiluminescence.

Light emission induced by chemical reactions, known as chemiluminescence (CL), has been widely used for bioassays, biosensors, imaging, and illumination applications. Most known CL systems exhibit flash-type single-color light emissions, which limit their applications. Long-lasting multicolor CL in aqueous solutions is highly desirable, especially for biological applications, but remains a challenge. Herein, we report a simple strategy of achieving highly efficient cascade Förster resonance energy transfer (FRET) in the dynamic nanoassembly of β-cyclodextrin (β-CD), CL reagents, and fluorophores in aqueous solution, which emits intensive multicolor CL with adjustable wavelength within 410-610 nm. β-CD can bind CL reagents and fluorophores to form a dynamic nanoassembly. These nanoassemblies can bring the included luminescent intermediate and fluorophores into close proximity and proper alignment, which should greatly enhance the FRET efficiency between luminescent intermediate and fluorophores. Indeed, the cascade FRET efficiency in this supramolecular nanoassembly reaches up to 92%, which is comparable with the cascade FRET systems based on covalently linked donors and acceptors. By using hydroxypropyl methylcellulose as the thickener to slow the diffusion (to elongate the CL emission), and using Ca(OH)2 solid (a low solubility strong base) as buffer to maintain the pH in the optimal range for the CL reaction, this nanoassembly system has been further developed to achieve slow-diffusion-controlled catalytic CL reactions, which enables long-lasting multicolor CL in aqueous solution that is visible to naked eyes and lasts for more than 20 h. The multicolor CL systems can be used to prepare transformable two-dimensional multicolor codes for encryption application.