Chemiluminescence Quantum Yield Research Articles

Near-Infrared Chemiluminescence Imaging of Chemotherapy-Induced Peripheral Neuropathy.

Chemotherapy-induced peripheral neuropathy (CIPN) has a high prevalence but is poorly managed for cancer patients due to the lack of reliable and sensitive diagnostic techniques. Molecular optical imaging can provide a noninvasive way for real-time monitoring of CIPN; However, this is not reported, likely due to the absence of optical probes capable of imaging deep into the spinal canal and possessing sufficient sensitivity for minimal dosage through local injection into the dorsal root ganglia. Herein, a near-infrared (NIR) chemiluminophore (MPBD) with a chemiluminescence quantum yield higher than other reported probes is synthesized and a NIR activatable chemiluminescent probe (CalCL) is developed for in vivo imaging of CIPN. CalCL is constructed by caging MPBD with calpain-cleavable peptide moiety while conjugating polyethylene glycol chain to endow water solubility. Due to the deep-tissue penetration of chemiluminescence and specific turn-on response of CalCL toward calpain (a hallmark of CIPN), it allows for sensitive detection of paclitaxel-mediated CIPN in living mice, which is unattainable by fluorescence imaging. This study thus not only develops a highly efficient chemiluminescent probe, but also presents the first optical imaging approach toward high-throughput screening of neurotoxic drugs.

In vivo three-dimensional brain imaging with chemiluminescence probes in Alzheimer's disease models.

Optical three-dimensional (3D) molecular imaging is highly desirable for providing precise distribution of the target-of-interest in disease models. However, such 3D imaging is still far from wide applications in biomedical research; 3D brain optical molecular imaging, in particular, has rarely been reported. In this report, we designed chemiluminescence probes with high quantum yields, relatively long emission wavelengths, and high signal-to-noise ratios to fulfill the requirements for 3D brain imaging in vivo. With assistance from density-function theory (DFT) computation, we designed ADLumin-Xs by locking up the rotation of the double bond via fusing the furan ring to the phenyl ring. Our results showed that ADLumin-5 had a high quantum yield of chemiluminescence and could bind to amyloid beta (Aβ). Remarkably, ADLumin-5's radiance intensity in brain areas could reach 4 × 107 photon/s/cm2/sr, which is probably 100-fold higher than most chemiluminescence probes for in vivo imaging. Because of its strong emission, we demonstrated that ADLumin-5 could be used for in vivo 3D brain imaging in transgenic mouse models of Alzheimer's disease.

Circularly polarized peroxyoxalate chemiluminescence with chiral activators

A series of planar chiral macrocyclic compounds derived from [2.2]-paracyclophane scaffold and helicenes in enantiomers were synthesized and found to be efficient circularly polarized emitters. These chiral macrocyclic compounds and helicenes were used as activators in peroxyoxalate chemiluminescence. Among the blue, green, or yellow chemiluminescent activators, compound 2R containing electron-donating dimethylamino groups with lowest oxidation potential showed the best chemiluminescence quantum yield of 0.21% (higher than 0.17% of 9,10-diphenylanthracene at the concentration of 1.0 × 10−4 mol dm−3). Appreciable circularly polarized chemiluminescence with dissymmetry factors (|gCL|) in the range of 1.4 × 10−3−5.4 × 10−3 have been recorded for these chiral chemiluminescent activators.

Ultrabright chemiluminescent scaffold for portable visualizing organophosphorus compounds

Chemiluminescence (CL) has been recognized as one of the most powerful tools in analytical assays with high signal-to-noise ratio. Ultrabright chemiluminophores are highly desired in CL-based analytical approaches, imaging, for example, although the design of CL scaffold with ultra-brightness remains a challenge. We report a feasible strategy for constructing an ultrabright chemiluminophore, BTCL-Cl, by grafting benzothiazole moiety to the dioxetane center of Schaap’s adamantylidene-dioxetane. Compared with the classical undecorated chemiluminophores, the CL quantum yield of BTCL-Cl has improved by 2.4-folds to 17.6% with a short half-life due to deprotonation under alkaline conditions. Probe CL-HMPC, the thiol-recognizer-decorated BTCL-Cl, has demonstrated ultrahigh sensitivity (detection limit is 6.0 ng/mL) in monitoring organophosphorus compounds (OPs) by immediate releasing of thiols after the alkaline hydrolysis of OPs. The OPs-triggered remarkable CL enhancement has ensured quantitively visualization of OPs in the naked eye by imaging with a smartphone in situ. Using the versatile and ultrasensitive CL platform, we succeeded in feasibly visualizing the concentration of OPs on cabbage leaves on farmland by portable setups. The simple and promising approach for analyzing pesticides and potentially other targets brings tremendous imagination in related areas.

Highly Bright Near-Infrared Chemiluminescent Probes for Cancer Imaging and Laparotomy.

Near-infrared (NIR) chemiluminescence imaging holds potential for sensitive imaging of cancer due to its low background; however, few NIR chemiluminophores are available, which share the drawback of low chemiluminescence quantum yields (ΦCL ). Herein, we report the synthesis of NIR chemiluminophores for cancer imaging and laparotomy. Molecular engineering of the electron-withdrawing group at the para-position of the phenol-dioxetane leads to a highly bright NIR chemiluminophore (DPT), showing the ΦCL (4.6×10-2 Einstein mol-1 ) that is 3 to 5-fold higher than existing NIR chemiluminophores. By caging the phenol group of DPT with a cathepsin B (CatB) responsive moiety, an activatable chemiluminescence probe (DPTCB ) is developed for real-time turn-on detection of deeply buried tumor tissues in living mice. Due to its high brightness, DPTCB permits accurate chemiluminescence-guided laparotomy.

Highly Bright Near‐Infrared Chemiluminescent Probes for Cancer Imaging and Laparotomy

AbstractNear‐infrared (NIR) chemiluminescence imaging holds potential for sensitive imaging of cancer due to its low background; however, few NIR chemiluminophores are available, which share the drawback of low chemiluminescence quantum yields (ΦCL). Herein, we report the synthesis of NIR chemiluminophores for cancer imaging and laparotomy. Molecular engineering of the electron‐withdrawing group at the para‐position of the phenol‐dioxetane leads to a highly bright NIR chemiluminophore (DPT), showing the ΦCL (4.6×10−2 Einstein mol−1) that is 3 to 5‐fold higher than existing NIR chemiluminophores. By caging the phenol group of DPT with a cathepsin B (CatB) responsive moiety, an activatable chemiluminescence probe (DPTCB) is developed for real‐time turn‐on detection of deeply buried tumor tissues in living mice. Due to its high brightness, DPTCB permits accurate chemiluminescence‐guided laparotomy.

An enhanced chemiluminescence hybrids of luminol by sulfonated polyaniline decorated copper-based metal organic frame composite applicable to the measurement of hydrogen peroxide in a wide pH range

Here, sulfonated polyaniline (SPAN) was decorated on the surface of copper-based metal organic frame (HKUST-1) and the composite was functionalized by luminol to construct a chemiluminescence (CL) hybrids (SPAN/HKUST-1@Luminol). The as-prepared SPAN/HKUST-1@Luminol demonstrated a great dispersion and stability performance in aqueous solution. Moreover, the resultant SPAN/HKUST-1@Luminol hybrids exhibited extremely strong CL properties, and the CL quantum yield was 136 times higher than that of luminol. In particular, it exhibited outstanding CL activity not only under alkaline conditions, but also under neutral conditions. The sensitive response of the hybrid to hydrogen peroxide was used to construct CL methods for the detection of hydrogen peroxide at a wide range of pH, with the detection limit of 60 nM at a neutral condition and 25 pM at alkaline condition. Due to strong and stable signal of the SPAN/HKUST-1@Luminol, the CL method provides a viable tool for determination of H2O2 in biological systems and enabled the monitoring of stimulated production of H2O2 released by living cells.

Solvent Effect on the Chemiluminescence of Acridinium Thioester: A Computational Study.

Chemiluminescent labelling, which is one of the promising procedures of modern immunodiagnostics, is increasingly carried out using acridinium derivatives, an oxidant, and an alkaline aqueous environment. However, the efficiency of the chemiluminescence of luminol or acridinium esters is higher in non-aqueous solvents such as dimethyl sulfoxide or acetonitrile. Therefore, the search for a new environment for the chemiluminescence reaction, especially the one characterized by a higher quantum yield of chemiluminescence, is one of the aims of current research. Using computational methods (DFT and TD DFT with PCM model of solvent), we examined thermodynamic and kinetic data concerning the chemiluminescence and competitive dark pathways. Our results suggest that better characteristics of the chemiluminescence reaction of acridinium thioester are observed in nonpolar solvents, such as methylcyclohexane, n-hexane and n-pentane, than in aqueous media used so far. Further experimental verification is necessary to confirm the possible application of proposed nonpolar solvents in chemiluminescent labelling and hence in immunodiagnostics.

A bright chemiluminescence conjugated polymer–mesoporous silica nanoprobe for imaging of colonic tumors in vivo

A chemiluminescence (CL) conjugated polymer–mesoporous silica nanoprobe with significant improvement of CL quantum yield obtained from direct oxidation of a conjugated polymer and its application for in vivo imaging of colonic tumors.

Aggregation-Induced Emission Effect within Peroxyoxalate-Loaded Mesoporous Silica Nanoparticles for Efficient Harvest of Chemiluminescence Energy in Aqueous Solutions.

Aggregation-induced emission (AIE) molecules that can avoid the aggregation-caused quenching (ACQ) effect and break the concentration limit have been widely used for biosensing. Similar to fluorescence dyes, AIE molecules can be chemiexcited simply by a peroxyoxalate-based chemiluminescence (CL) reaction, but the hydrolysis of peroxyoxalate is often a problem in an aqueous solution. Herein, we report an AIE effect within peroxyoxalate-loaded silica nanoparticles (PMSNs) for an efficient harvest of CL energy as well as alleviation of bis(2,4,5-trichloro-6-carbopentoxyphenyl) oxalate (CPPO) hydrolysis. Peroxyoxalate (i.e., CPPO) and AIE molecules (i.e., 1,2-benzothiazol-2-triphenylamino acrylonitrile, BTPA) were loaded together within the mesoporous silica nanoparticles (MSNs) to synthesize the BTPA-PMSN nanocomposite. The BTPA-PMSNs not only allowed CPPO to be dispersed well in an aqueous solution but also avoided the hydrolysis of CPPO. Meanwhile, the proximity between BTPA and CPPO molecules in the mesopores of MSNs facilitated the BTPA aggregate to harvest the energy from CL intermediates. Hence, the CL system of BTPA-PMSNs can work efficiently in aqueous solutions at a physiological pH. The CL quantum yield of the BTPA-PMSN system was measured to be 9.91 × 10-5, about 20 000-fold higher than that obtained in the rhodamine B (RhB, a typical ACQ dye)-PMSN system. Using BTPA-PMSNs for H2O2 sensing, a limit of detection (LOD) as low as 5 nM can be achieved, 1000-fold lower than that achieved in the RhB-PMSNs system. Due to the feasibility of working at a physiological pH, this CL system is also quite suitable for the detection of oxidase substrates such as glucose and cholesterol. This BTPA-PMSN CL system with the merits of high CL quantum yield at a physiological pH is appealing for biosensing.

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

Self-organized plasmonic metasurfaces: The role of the Purcell effect in metal-enhanced chemiluminescence (MEC)

Chemiluminophores are entities, which exhibit wide-band light emission without any external light source, just caused by a chemical reaction. Since chemiluminescence usually yields to unfavorable competition with other channels of chemical energy dissipation, plasmonic nanoparticles can be employed to enhance the chemiluminescence quantum yield via acceleration of the radiative decay rate due to the Purcell effect. On the other hand, the catalytic action of metallic surface can contribute to the chemical reaction rate. Both mechanisms can lead to substantial chemiluminescence intensity enhancement when chemiluminophores are in contact with metal nanoparticles. Although the investigations devoted to MEC are numerous, the relative roles of the Purcell effect and catalysis in the chemiluminescence enhancement are still unclear. In this paper, with the use of a thin inert spacer layer deposited on top of a silver metasurface, we observe a moderate decrease of the chemiluminescence enhancement, which favors an electrodynamic mechanism. We also check that the continuous silver film without plasmon resonances causes no measurable chemiluminescence enhancement. As the results supported the electrodynamic mechanism of MEC, silver nanoparticles with suitable properties have been fabricated via physical vapor deposition on the substrate. We have theoretically optimized the silver nanoparticles shape and size distributions to tune their localized surface plasmon bands for the best overlap with the emission of luminol and some other chemiluminophores. Our design for plasmonic nanoparticles placed on the dielectric material may motivate a new generation of chemiluminescence-based devices for sensing applications.

Chemiluminescence Detection in the Study of Free-Radical Reactions. Part 1.

The present review, consisting of two parts, considers the application of the chemiluminescence detection method in evaluating free radical reactions in biological model systems. The first part presents a classification of experimental biological model systems. Evidence favoring the use of chemiluminescence detection in the study of free radical reactions, along with similar methods of registering electromagnetic radiation as electron paramagnetic resonance, spectrophotometry, detection of infrared radiation (IR spectrometry), and chemical methods for assessing the end products of free radical reactions, is shown. Chemiluminescence accompanying free radical reactions involving lipids has been the extensively studied reaction. These reactions are one of the key causes of cell death by either apoptosis (activation of the cytochrome c complex with cardiolipin) or ferroptosis (induced by free ferrous ions). The concept of chemiluminescence quantum yield is also discussed in this article. The second part, which is to be published in the next issue, analyzes the application of chemiluminescence detection using luminescent additives that are called activators, a.k.a. chemiluminescence enhancers, and enhance the emission through the triplet–singlet transfer of electron excitation energy from radical reaction products, followed by light emission with a high quantum yield.

Chemiluminescent carbon nanodots as sensors for hydrogen peroxide and glucose

Abstract Hydrogen peroxide (H2O2) is an important product generated in the body and related to many pathophysiological processes and glucose metabolism disorder can cause many fatal diseases in living bodies. Therefore, the sensing of H2O2 and glucose is of great significance in disease diagnostics and treatment. Fluorescent carbon dots (CDs) are one new class of nanoprobes for H2O2 and glucose. Nevertheless, the CD-based sensor is always based on its fluorescence response, which is influenced by the auto-fluorescent interference. Herein, efficient fluorescent CDs were synthesized by one-pot solvothermal method, and the CDs exhibit bright and persistent deep-red (DR) chemiluminescence (CL) in bis(2,4,6-trichlorophenyl) oxalate and H2O2 solution with a CL quantum yield of (8.22 ± 0.30) × 10−3, which is amongst the highest values in ever reported nanomaterials for chemical analysis. Employing the CDs as CL nanoprobes, sensitive sensing for H2O2 has been achieved with a detection limit of 11.7 μM, and further for glucose detection with a detection limit of 12.6 μM. The DR CL CDs is promising to be applied in blood glucose analysis or in vivo biosensor.

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.

Bright near-infrared chemiluminescent dyes: Phthalhydrazides conjugated with fluorescent BODIPYs

A series of phthalhydrazides conjugated with NIR fluorescent BODIPY dyes were synthesized (three steps, overall yields 68–83%) and found to show strong NIR chemiluminescence (CL) with maxima in the range of 670–736 nm. One of these showed a CL quantum yield reaching 8.4 times higher than that of luminol. Tuning of the fluorescence band of the BODIPY unit directly leads to a red-shifted CL, developing a strategy for designing NIR chemiluminogens.

Efficient chemiluminescent ZnO nanoparticles for cellular imaging

Abstracts Chemiluminescence (CL) induced by peroxalate fuel and hydrogen peroxide has been widely applied in chemical detection and bioimaging. Nevertheless, the chemiluminescent emitters in the CL are focused on organic small-molecular dyes, most of which encounter serious obstacles in practical application due to their potential biotoxicity and low photostability. Here, bright blue CL is observed when biocompatible zinc oxide nanoparticles (ZnO NPs) with yellow photoluminescence (PL) are added into peroxalate and hydrogen peroxide solution, which is originated from the interaction between the zinc interstitial of ZnO NPs and the energy-rich intermediate produced in the CL process. With the modification of silane coupler, the CL quantum yield of ZnO NPs presents two orders of magnitude increase from 6.2× 10−6 to record 3.7 × 10−4 E⋅mol−1 for inorganic NPs owing to the protective effect from silicon oxide shell layer. By virtual of excellent CL ability, ZnO NPs have been firstly used as CL probes in bioimaging, which opens the way to a new design freedom for biosensor or bioimaging in the future.

Persistent Chemiluminescent Glow of Phenoxy-dioxetane Luminophore Enables Unique CRET-Based Detection of Proteases.

Chemiluminescence is being considered an effective imaging modality as it offers low background and high sensitivity. Recent discovery by our group has led to development of new phenoxy-dioxetane chemiluminescence luminophores, which are highly bright under physiological conditions. However, the current scope of probes based on these luminophores is limited, as they can only be turned on by phenol protecting group removal. Here we present a new chemiluminescence resonance energy transfer (CRET) system, Glow-CRET, in which light emission is triggered by proteolytic cleavage of a peptide substrate that links a dioxetane luminophore and a quencher. In order to compose such system, a new phenoxy-dioxetane luminophore, 7-HC-CL, was developed. This luminophore exhibits intense and persistent glow chemiluminescence; it undergoes very slow chemiexcitation, and it has the highest chemiluminescence quantum yield ever reported under physiological conditions. Based on 7-HC-CL, a Glow-CRET probe for matrix metalloproteinases, MMP-CL, was synthesized. Incubation of MMP-CL with its cognate protease resulted in 160-fold increase in chemiluminescence signal. MMP-CL was also able to detect matrix metalloproteinase activity in cancer cells with significantly higher signal-to-background ratio than an analogous fluorescence resonance energy transfer (FRET)-based probe. This work is expected to open new horizons in chemiluminescence imaging, as it enables to use the dioxetanes in ways that had not been possible. We anticipate that 7-HC-CL and future derivatives will be utilized not only for the construction of further Glow-CRET probes, but also for other applications, such as chemiluminescence tagging of proteins.

Recent Advances and Challenges in Luminescent Imaging: Bright Outlook for Chemiluminescence of Dioxetanes in Water.

Chemiluminescence is gradually being recognized as a powerful tool for sensing and imaging. Most known light-emitting compounds undergo chemiexcitation through spontaneous decomposition of cyclic peroxide moieties. A ground-breaking milestone in the chemistry of such compounds was achieved 30 years ago with the discovery of triggerable dioxetanes by Schaap’s group. Our group has recently developed a distinct methodology to significantly improve the light emission efficiency of such phenoxy-dioxetane luminophores under physiological conditions. Introduction of an electron-withdrawing substituent at the ortho position of the phenoxy-dioxetane resulted in an approximately 3000-fold increase of the chemiluminescence quantum yield in aqueous media. Furthermore, we discovered that the emission wavelength and the kinetics of the chemiexcitation could be determined by the electronic nature of the substituent incorporated on the dioxetane luminophore. This recent development has provided scientists with new powerful chemiluminophores that can act as single-component probes for in vivo and in vitro detection and imaging of various analytes and enzymes. This outlook describes the recent progress toward applications of synthetic chemiluminescence luminophores suitable for sensing and imaging in aqueous environments.

Bright and Multicolor Chemiluminescent Carbon Nanodots for Advanced Information Encryption.

The various luminescent properties of carbon nanodots (CDs) reveal fascinating applications in several areas. Here, bright and multicolor chemiluminescence (CL) is realized from CDs, whose CL quantum yield can be optimized by adjusting the energy level alignment between the CDs and 1,2‐dioxetanedione intermediate generated from the reaction of peroxalate and hydrogen peroxide. A CL quantum yield of 9.32 × 10−3 Einsteins mol−1, maximal luminance of 3.28 cd m−2, and lifetime of 186.4 s are achieved in red CDs, all of which are the best values ever reported for CDs. As a proof‐of‐concept prototype, a high‐quality information encryption strategy is established via CD based CL imaging techniques by virtue of the high brightness and multicolor CL.