Chemiluminescence Research Articles

FeS2 nanosheets-luminol-O2 chemiluminescence method for determination of venlafaxine hydrochloride, imipramine hydrochloride, and cefazolin sodium.

This study introduces a novel chemiluminescence (CL) approach utilizing FeS2 nanosheets (NSs) catalyzed luminol-O2 CL reaction for the measurement of three pharmaceuticals, namely venlafaxine hydrochloride (VFX), imipramine hydrochloride (IPM), and cefazolin sodium (CEF). The CL method involved the phenomenon of quenching induced by the pharmaceuticals in the CL reaction. To achieve the most quenching efficacy of the pharmaceuticals in the CL reaction, the concentrations of reactants comprising luminol, NaOH, and FeS2 NSs were optimized accordingly. The calibration curves demonstrated exceptional linearity within the concentration range spanning from 4.00 × 10-7 to 1.00 × 10-3mol L-1, 1.00 × 10-7 to 1.00 × 10-4mol L-1, and 4.00 × 10-6 to 2.00 × 10-4mol L-1 with detection limits (3σ) of 3.54 × 10-7, 1.08 × 10-8, and 2.63 × 10-6mol L-1 for VFX, IPM, and CEF, respectively. This study synthesized FeS2 NSs using a facile hydrothermal approach, and then the synthesized FeS2 NSs were subjected to a comprehensive characterization using a range of spectroscopic methods. The proposed CL method was effective in measuring the aforementioned pharmaceuticals in pharmaceutical formulations as well as different water samples. The mechanism of the CL system has been elucidated.

FDevelopment of Self-Activated Photosensitizers based on the Chemiluminescent System of Marine Coelenterazine

IntroductionPhotodynamic therapy (PDT) of cancer possesses advantageous features, such as a minimally invasive nature and few side-effect [1]. However, its use can be restricted to more surface tumors, due to its dependance on light-irradiation. To overcome this problem, we propose the development of single-molecule photosensitizers (PSs), based on chemiluminescent (CL) marine Coelenterazine (Clz) [2-6], which can be self-activated in the absence of light. ApproachClz analogs were synthesized via routes optimized by our team [2-6], and their structure was characterized by HR-MS, NMR and FTIR spectroscopy. They were subjected to a through luminometric and photophysical characterization, to determine their CL features and singlet oxygen sensitization [2-6]. Their toxicity was investigated in vitro toward different cancer (breast, prostate, neuroblastoma, lung and gastric) and noncancer (breast and keratinocytes) cell lines, via the MTT assay in the absence of light [2-6]. ResultsThe obtained Clz analogs were designed so their CL reaction generate mainly triplet states, instead of singlet excited ones [2-6]. They were shown to indeed be able to sensitize the highly cytotoxic singlet oxygen, without light-irradiation, due to a CL reaction triggered solely by molecule overexpressed in cancer cells (superoxide anion) [2-6]. In vitro assays showed that these analogs present cytotoxicity toward all the different studied cancer cell lines [2-6]. Moreover, some of them even showed comparable or even better activity than a reference chemotherapeutic drug [3,4]. Finally, a promising profile of safety was observed in testing with noncancer cells [3]. ConclusionsDifferent single-molecule PSs were developed, which are capable of intracellular self-activation without light-irradiation [2-6]. Namely, they are directly chemiexcited to triplet excited states via a CL reaction triggered by a molecule overexpressed in cancer cells, which generates singlet oxygen without light-irradiation. This new approach was found to induce toxicity toward different cancer cell lines, while possessing a promising profile of safety for noncancer cells. Thus, these PSs can provide a pathway for eliminating the light-related restrictions of PDT, while maintaining its advantages.

Label-free and portable detection of HIV-DNA by a handheld luminometer

BackgroundThe human immunodeficiency virus (HIV) remains a major worldwide health problem. Nowadays, many methods have been developed for quantitative detecting human immunodeficiency virus DNA (HIV-DNA), such as fluorescence and colorimetry. However, these methods still have the disadvantages of being expensive and requiring professional technicians. Early diagnosis of pathogens is increasingly dependent on portable instruments and simple point-of-care testing (POCT). Therefore, it is meaningful and necessary to develop portable and cheap methods for detecting disease markers. ResultsIn this work, a label-free chemiluminescence (CL) method was developed for detecting HIV-DNA via a handheld luminometer. To achieve label-free target detection, the CL catalyst, G-triplex-hemin DNAzyme (G3-hemin DNAzyme), was in-situ assembled in the presence of HIV-DNA. For improving sensitivity, HIV-DNA induced the cyclic strand displacement reaction (SDR), which can form three G3-hemin DNAzymes in one cycle. So, the chemiluminescence reaction between luminol and H2O2 was highly effectively catalyzed, and the CL intensity was linearly related with the concentration of HIV-DNA in the range of 0.05–10 nM with a detection limit of 29.0 pM. Due to the high specificity of hairpin DNA, single-base mismatch can be discriminated, which ensured the specific detection of HIV-DNA. SignificanceIn-situ formation of G3-hemin DNAzyme led to label-free and selective detection without complex synthesis and functionalization. Therefore, it offers a cheap, selective, sensitive and portable method for detecting disease-related genes, which is promising for POCT of clinical diagnosis in resource-limited settings.

Chemiluminescence and electrochemiluminescence of water-soluble iridium(III) complexes containing a tetraethylene-glycol functionalised triazolylpyridine ligand

BackgroundIridium(III) complexes, exhibiting high luminescence quantum yields and a wide range of emission colours, are promising alternatives to tris(2,2ʹ-bipyridine)ruthenium(II) for chemiluminescence (CL) and electrochemiluminescence (ECL) detection. This emerging class of reagent, however, is limited by the poor solubility of many iridium(III) complexes in aqueous solution, and lack of understanding of their remarkably variable selectivities towards different analytes. ResultsSeven [Ir(C^N)2(pt-TEG)]+ complexes, exhibiting a wide range of reduction potentials and emission energies, were examined with six model analytes. For CL, cerium(IV) was used as the oxidant. The alkylamine analytes generally produced greater CL and ECL with the more readily oxidised Ir(III) complexes (C^N = piq, bt, ppy), predominantly through the ‘direct’ pathway requiring oxidation of both metal complex and analyte. Aniline derivatives that did not also contain secondary or tertiary alkylamines elicited CL from the less readily oxidised complexes (C^N = df-ppy-CF3, df-ppy) via energy transfer. The most difficult to oxidise complexes (C^N = df(CF3)-ppy-Me, df(CN)-ppy) gave poor responses due to the limited potential window of the solvent and inefficiency of energy transfer to their high energy excited states. Greater CL and/or ECL intensities were generally obtained for each analyte with at least one Ir(III) complex than with [Ru(bpy)3]2+; superior limits of detection for two analytes were demonstrated. SignificanceThis exploration of CL/ECL in which the properties of luminophore, analyte and oxidant are all varied provides a new understanding of the influence of the metal-complex potentials and excited state energy on the light-producing and quenching pathways, and consequently, their distinct selectivity towards different analytes. These findings will guide the development of water-soluble Ir(III) complexes as CL and ECL reagents.

Exploring Simple Particle-Based Signal Amplification Strategies in a Heterogeneous Sandwich Immunoassay with Optical Detection.

Heterogeneous sandwich immunoassays are widely used for biomarker detection in bioanalysis and medical diagnostics. The high analyte sensitivity of the current "gold standard" enzyme-linked immunosorbent assay (ELISA) originates from the signal-generating enzymatic amplification step, yielding a high number of optically detectable reporter molecules. For future point-of-care testing (POCT) and point-of-need applications, there is an increasing interest in more simple detection strategies that circumvent time-consuming and temperature-dependent enzymatic reactions. A common concept to aim for detection limits comparable to those of enzymatic amplification reactions is the usage of polymer nanoparticles (NP) stained with a large number of chromophores. We explored different simple NP-based signal amplification strategies for heterogeneous sandwich immunoassays that rely on an extraction-triggered release step of different types of optically detectable reporters. Therefore, streptavidin-functionalized polystyrene particles (PSP) are utilized as carriers for (i) the fluorescent dye coumarin 153 (C153) and (ii) hemin (hem) molecules catalyzing the luminol reaction enabling chemiluminescence (CL) detection. Additionally, (iii) NP labeling with hemin-based microperoxidase MP11 was assessed. For each amplification approach, the PSP was first systematically optimized regarding size, loading concentration, and surface chemistry. Then, for an immunoassay for the inflammation marker C-reactive protein (CRP), the analyte sensitivity achievable with optimized PSP systems was compared with the established ELISA concept for photometric and CL detection. Careful optimization led to a limit of detection (LOD) of 0.1 ng/mL for MP11-labeled PSP and CL detection, performing similarly well to a photometric ELISA (0.13 ng/mL), which demonstrates the huge potential of our novel assay concept.

Single-holed cobalt - nitrogen - carbon hollow structure with oxidase-mimicking activity for the chemiluminescence determination of β - galactosidase activity.

A single-holed cobalt - nitrogen - carbon (Co - N - C) hollow structure nanozyme has been fabricated by in situ growth of zeolitic imidazolate framework (ZIF - 67) on the polystyrene (PS) sphere and following treatment by high-temperature carbonization. The Co - N - C nanostructure mimics the activity of oxidase and can activate O2 into reactive oxygen species (ROS), giving a remarkable enhancement on the chemiluminescence (CL) signal of luminol - O2 reaction. The Co - N - C oxidase mimic has further been exploited in the biosensing field by the determination of the activity of β - galactosidase (β - gal). The CL method for β - gal activity has a linear range of 0.5mU·L-1 to 5.0 U·L-1, a detection limit of 0.167mU·L-1, and the precision of 3.1% (5.0 U·L-1, n = 11). This method has been employed to assess inhibitor screening of β - gal and determine activity of β - gal in spiked human serum samples.

Green synthesized carbon quantum dots as chemiluminescence sensor for sulfanilamide detection

N–S co-doped quantum carbon dots (N–S-CQD) were synthesized using a hydrothermal method with Artemisia annua L. as a precursor and dl-cysteine as the nitrogen-sulfur source. N–S-CQD can enhance the chemiluminescence (CL) intensity of KMnO4 system, while sulfanilamide (SA) is capable of significantly inhibit the CL intensity of KMnO4-(N–S-CQD) system. Based on this finding, we developed a novel CL method for the determination of SA. Under the optimal conditions, SA could be accurately determined in the concentration range of 50–1600 μM with a limit of detection of 0.22 μM. The investigation of potential interferences and recovery rates confirmed the method's suitability for assessing biomass samples.

‘Three Birds With One Stone’ functionalized metal–organic frameworks for facile and efficient chemiluminescent immunoassays

The luminol–H2O2 system is crucial in the field of chemiluminescence (CL) analysis. However, luminol exhibits improved solubility and luminescence only in an alkaline environment, and its preparation process is cumbersome. This inconvenience highlights the need for developing a simple and universally applicable method in this regard. This study integrates luminol and a catalyst into metal–organic frameworks (MOFs) for fabrication of functionalised MOF nanoparticles. Further, PEGylated hematin (PEG = polyethylene glycol) was prepared. This modification with PEG enhanced the catalytic properties of hematin and facilitated the formation of zeolitic imidazole framework-8 nanoparticles. Furthermore, the built-in catalyst enhanced the CL in terms of strength and persistence. These MOF nanoparticles were used as signal markers to fabricate a sandwich-type CL immunosensor for detection of carcinoembryonic antigen, which is a disease marker, following which highly satisfactory analytical test results are obtained. This approach of integrating luminophores and catalysts offers a new idea for generating novel materials in the CL analysis field.

Ligand-assisted excitation of Eu(III) during interaction of Eu(FOD)3 with xenon difluoride in acetonitrile solution

The interaction of tris(1,1,1,2,2,3,3-heptafluoro-7,7-dimethyl-4,6-octanedionato)europium(III), (Eu(FOD)3), with xenon difluoride in acetonitrile solution was found to be accompanied by chemiluminescence (CL). The kinetic curve of CL at a ratio of reagents Eu3+/XeF2 of 1:2 has a complex form; an initial rapid decrease is replaced by an increase in CL intensity, the maximum of which is reached approximately 10 min after the start of the reaction. Next, an exponential decay of the CL intensity is observed over several tens of minutes. The CL spectrum is located in the wavelength range 400–750 nm and corresponds to the emission of an electronically excited europium (III) ion coordinated with FOD and fluoride ion. Spectral methods were used to identify the reaction products – europium (III) fluoride in the sediment and oxygen difluoride in the gas phase. A mechanism for chemiexcitation of europium(III) has been proposed, including: 1) acceptance of fluorine anion from the XeF2 molecule by europium ion with the formation of active intermediate XeF+; 2) oxidative fluorination of the ligand, which is initiated by the interaction of oxygen atom of the FOD ligand with XeF+ cation and ends with the formation of oxygen difluoride and the electronically excited product P*, presumably a fluorinated ketone; 3) non-radiative transfer of excitation energy from P* to the europium ion within its coordination sphere, followed by its radiative deactivation.

Aggregation-Induced Emission-Based Chemiluminescence Systems in Biochemical Analysis and Disease Theranostics.

Chemiluminescence (CL) is of great significance in biochemical analysis and imaging due to its high sensitivity and lack of need for external excitation. In this review, we summarized the recent progress of AIE-based CL systems, including their working mechanisms and applications in biochemical analysis, bioimaging, and disease diagnosis and treatment. In ion and molecular detection, CL shows high selectivity and high sensitivity, especially in the detection of dynamic reactive oxygen species (ROS). Further, the integrated NIR-CL single-molecule system and nanostructural CL platform harnessing CL resonance energy transfer (CRET) have remarkable advantages in long-term imaging with superior capability in penetrating deep tissue depth and high signal-to-noise ratio, and are promising in the applications of in vivo imaging and image-guided disease therapy. Finally, we summarized the shortcomings of the existing AIE-CL system and provided our perspective on the possible ways to develop more powerful CL systems in the future. It can be highly expected that these promoted CL systems will play bigger roles in biochemical analysis and disease theranostics.

Chemiluminescent Conjugated Polymer Nanoparticles for Deep-Tissue Inflammation Imaging and Photodynamic Therapy of Cancer.

Deep-tissue optical imaging and photodynamic therapy (PDT) remain a big challenge for the diagnosis and treatment of cancer. Chemiluminescence (CL) has emerged as a promising tool for biological imaging and in vivo therapy. The development of covalent-binding chemiluminescence agents with high stability and high chemiluminescence resonance energy transfer (CRET) efficiency is urgent. Herein, we design and synthesize an unprecedented chemiluminescent conjugated polymer PFV-Luminol, which consists of conjugated polyfluorene vinylene (PFV) main chains and isoluminol-modified side chains. Notably, isoluminol groups with chemiluminescent ability are covalently linked to main chains by amide bonds, which dramatically narrow their distance, greatly improving the CRET efficiency. In the presence of pathologically high levels of various reactive oxygen species (ROS), especially singlet oxygen (1O2), PFV-Luminol emits strong fluorescence and produces more ROS. Furthermore, we construct the PFV-L@PEG-NPs and PFV-L@PEG-FA-NPs nanoparticles by self-assembly of PFV-Luminol and amphiphilic copolymer DSPE-PEG/DSPE-PEG-FA. The chemiluminescent PFV-L@PEG-NPs nanoparticles exhibit excellent capabilities for in vivo imaging in different inflammatory animal models with great tissue penetration and resolution. In addition, PFV-L@PEG-FA-NPs nanoparticles show both sensitive in vivo chemiluminescence imaging and efficient chemiluminescence-mediated PDT for antitumors. This study paves the way for the design of chemiluminescent probes and their applications in the diagnosis and therapy of diseases.

Investigation of the Chemiluminescent Reaction of a Fluorinated Analog of Marine Coelenterazine.

Bioluminescence (BL) and chemiluminescence (CL) are remarkable processes in which light is emitted due to (bio)chemical reactions. These reactions have attracted significant attention for various applications, such as biosensing, bioimaging, and biomedicine. Some of the most relevant and well-studied BL/CL systems are that of marine imidazopyrazine-based compounds, among which Coelenterazine is a prime example. Understanding the mechanisms behind efficient chemiexcitation is essential for the optimization and development of practical applications for these systems. Here, the CL of a fluorinated Coelenterazine analog was studied using experimental and theoretical approaches to obtain insight into these processes. Experimental analysis revealed that CL is more efficient under basic conditions than under acidic ones, which could be attributed to the higher relative chemiexcitation efficiency of an anionic dioxetanone intermediate over a corresponding neutral species. However, theoretical calculations indicated that the reactions of both species are similarly associated with both electron and charge transfer processes, which are typically used to explain efficiency chemiexcitation. So, neither process appears to be able to explain the relative chemiexcitation efficiencies observed. In conclusion, this study provides further insight into the mechanisms behind the chemiexcitation of imidazopyrazinone-based systems.

Hemin/G-quadruplex functionalized porphyrin-based MOF nanozymes and their application in mediating long-lasting chemiluminescence optical fiber aptasensor for sensitive and accurate detection of ricin

A novel hemin/G-quadruplex functionalized porphyrin-based MOF nanozyme (HGP-PCN) was firstly synthesized and employed to fabricate a chemiluminescence (CL) assay strategy for ricin detection. Porphyrin-based MOFs with large specific area could fully expose their catalytic centers, provide functional interface to load hemin/G-quadruplex, and then generate “double catalytic activity amplification”. The catalytic mechanism of HGP-PCN was thoroughly illustrated by chemical characterizations and theoretical calculations. The continuous generation of •OH, O2•−, and 1O2 from H2O2 catalyzed by Fe-N4 active sites on the HGP-PCN nanozyme could induce long-lasting and stable CL signals, which is helpful to fabricate sensitive and accurate CL sensing platform. The HGP-PCN nanozymes mediated long-lasting CL optical fiber aptasensor (CN-LCOFA) was fabricated to quantify ricin. The ricin toxic B (RTB) chain aptamers labelled HGP-PCN (Apt-HGP-PCN) was used for signaling while functionalized optical fiber probe was used as biorecognition interface. The CN-LCOFA could ultra-sensitively detect ricin within 23 min, the dynamic linear range was 4.1–185.0 ng/mL, and the LOD was 1.28 ng/mL. The analytical performance of CN-LCOFA including detection time, detection range and LOD was significantly superior to the ricin detection methods that reported in currently literatures. The detection accuracy of CN-LCOFA for ricin spiked in human serum was comparable with that of HPLC-MS. This novel nanozyme-catalyzed long-lasting CL system and ultrasensitive assay strategy could provide effective methods for food safety and environmental monitoring.

Dynamically regulating transient chemiluminescence of illuminated carbon nitride for simultaneous determination of ascorbic acid and dopamine

Developing a new strategy for a chemiluminescence (CL) sensor array to identify multiple biomarkers for psychiatric disorders simultaneously is a highly challenging task. This study designed a novel and straightforward strategy for simultaneous ascorbic acid (AA) and dopamine (DA) determination based on the interesting transient CL (TCL) kinetic curve tunability phenomenon on efficient graphite carbon nitride (CN) nanosheets. Advanced photoinduction strategies were introduced to synthesize light-illuminated CN nanosheets (L-CNNSs) as sensing materials with more negative reduction potential, excellent electron-hole separation, charge transfer capabilities, and high CL activity. Notably, using L-CNNSs as a sensing material could induce strong CL of alkaline lucigenin. This newly developed CL sensor exhibited high activity, excellent selectivity, and characteristic transient response toward AA and DA. Based on this finding, we developed a direct CL sensing platform for DA and AA discrimination in the urine of patients with mental disorders. Through many experiments, we attributed the CL recognition mechanism of the L-CNNSs/lucigenin system for DA and AA to the dynamic regulation of superoxide anions (O2·−) generation in the L-CNNSs solution. The different O2·− generation rates from L-CNNSs/lucigenin/AA and L-CNNSs/lucigenin/DA were regulated to obtain ‘flash-type’ and ‘sustained-type’ TCL curves, respectively, achieving simultaneous AA and DA discrimination and detection. This study provides insights for the simultaneous identification of multiple components based on CL sensors and offers new possibilities for practical analysis of sensor arrays.

Field Quantification of Hydroxyl Radicals by Flow-Injection Chemiluminescence Analysis with a Portable Device.

Hydroxyl radical (•OH) is a powerful oxidant abundantly found in nature and plays a central role in numerous environmental processes. On-site detection of •OH is highly desirable for real-time assessments of •OH-centered processes and yet is restrained by a lack of an analysis system suitable for field applications. Here, we report the development of a flow-injection chemiluminescence analysis (FIA-CL) system for the continuous field detection of •OH. The system is based on the reaction of •OH with phthalhydrazide to generate 5-hydroxy-2,3-dihydro-1,4-phthalazinedione, which emits chemiluminescence (CL) when oxidatively activated by H2O2 and Cu3+. The FIA-CL system was successfully validated using the Fenton reaction as a standard •OH source. Unlike traditional absorbance- or fluorescence-based methods, CL detection could minimize interference from an environmental medium (e.g., organic matter), therefore attaining highly sensitive •OH detection (limits of detection and quantification = 0.035 and 0.12 nM, respectively). The broad applications of FIA-CL were illustrated for on-site 24 h detection of •OH produced from photochemical processes in lake water and air, where the temporal variations on •OH productions (1.0-12.2 nM in water and 1.5-37.1 × 107 cm-3 in air) agreed well with sunlight photon flux. Further, the FIA-CL system enabled field 24 h field analysis of •OH productions from the oxidation of reduced substances triggered by tidal fluctuations in coastal soils. The superior analytical capability of the FIA-CL system opens new opportunities for monitoring •OH dynamics under field conditions.

Chemiluminescence initiated by nebulization of oxidant- and catalyst-free aqueous luminol solutions

Chemiluminescence (CL), i.e., the emission of light during chemical reactions without external optical excitation, is widely used in clinical medicine, bioassays, reporter gene assays, and bioimaging. Given the complexity of traditional CL systems, which typically contain catalysts and oxidants, one-component (i.e., luminophore-only) alternatives are urgently required. Herein, to demonstrate the feasibility of such simple systems, we realize CL by nebulizing oxidant- and catalyst-free aqueous luminol solutions and demonstrate that it originates from the oxidation of luminol by the •OH radicals spontaneously formed on the microdroplet surface. The higher intensity of this CL system compared to that observed for a reference bulk-phase CL system containing H2O2 as an oxidant and FeSO4 as a catalyst is ascribed to the high specific surface area and luminol adsorption capacity of the microdroplets, and excess hydroxide ions on their surface. Thus, this work demonstrates that microdroplets provide a favorable environment for CL reactions and paves the way for the establishment of one-component CL systems.

Development of chemiluminescent systems and devices for analytical applications.

Chemiluminescence (CL) refers to the light-emitting phenomenon resulting from chemical reactions. Due to its simplicity in terms of instrumentation and high sensitivity, CL plays a critical role in analytical chemistry and has developed rapidly in recent years. In this review, we discuss the efforts made by our group in the field of CL. This includes exploring new luminophores that function under neutral pH conditions, developing oxidant- and reactive oxygen species-based coreactants (e.g. artemisinin and thiourea dioxide) for luminol and lucigenin CL, utilizing nanomaterial-based CL signal amplification and employing innovative ultrasound devices for CL and their analytical applications. We discussed the CL amplification mechanisms of these systems in detail. Finally, we summarize the challenges and prospects for the future development of CL.

A novel chemiluminescence sensor for alpha-fetoprotein detection based on an aptamer-luminol modified magnetic graphene oxide and copper-based MOF composite.

Herein, an aptamer-luminol modified magnetic graphene oxide and copper-based MOF composite was prepared and used to build a novel target-triggered "turn on" chemiluminescence (CL) sensor for alpha-fetoprotein (AFP) detection. Magnetic graphene oxide (MGO) was functionalized with the complementary sequence of the AFP aptamer (cDNA), and then MGO-cDNA was linked to aptamer modified luminol (Apt-luminol) through the complementary base pairing effect. The functionalized magnetic graphene oxide (MGO-cDNA/Apt-luminol) was prepared as a specific magnetic separation and signal switch material. ZnONPs-Au@CuMOFs shows excellent catalytic performance and was used as a catalyst for the luminol-H2O2 reaction. AFP will specifically recognize and bind to Apt on MGO-cDNA/Apt-luminol when AFP is present, which causes luminol release and triggers the CL reaction. The released luminol encounters ZnONPs-Au@CuMOFs and produces strong CL intensity. Therefore, a novel target-triggered "turn on" CL method with high selectivity and sensitivity for detecting AFP has been established. The linear range and detection limit were 1.0 × 10-4-50 ng mL-1 and 4.2 × 10-5 ng mL-1, respectively. The sensor also exhibited good selectivity, reproducibility and stability, and was finally used for AFP detection in serum samples.

High sensitivity and automatic chemiluminescence detection of glucose and lactate using a spin-disc paper-based device.

This paper reports a spin-disc paper-based device with 10 individual detection units containing electromagnetic modules controlling the sample incubation time before chemiluminescence (CL) signal detection. After the sample was added to the top paper chip and incubated with the enzyme, the electromagnet was turned off to allow contact between the top and bottom paper. The H2O2 generated by the sample flowed vertically to the bottom paper and initiated the oxidase of the luminol to generate the CL signal. After one detection the disc was automatically rotated to the next position to repeat the above detection. The advantage of using the device over the lateral flow and the in situ detection was firstly proved using the detection of H2O2 and the glucose/lactate sample with 5 minute incubation. The CL intensity was increased 300 times/1000 times as the glucose/lactate was incubated for 5 minutes compared to the non-incubated samples. Afterward, the device was employed to separately detect glucose and lactate diluted in PBS, artificial sweat, artificial saliva, and fresh cell culture media. Finally, the device was employed to detect the glucose and lactate in the media collected over the 24 hour culture of PC3 cells. The uptake and production rates of glucose and lactate were correspondingly determined as 0.328 ± 0.015 pmol h-1 per cell and 1.254 ± 0.053 pmol h-1 per cell, respectively. The reported device has wide application potential due to its capabilities in automatic detection of multiple samples with very high sensitivity and small sample volume (down to 0.5 μL).

Gold brocade coated CoFe PBA with enhanced peroxidase-like activity for a chemiluminescent imaging immunoassay.

Traditional chemiluminescence (CL) imaging immunoassays usually rely on natural enzymes as catalytic probes, which has hampered their extensive application due to the susceptibility to inactivation of natural enzymes. In response, a gold brocade coated CoFe Prussian blue analogue (CoFe PBA@Au brocade) with enhanced peroxidase-like activity was synthesized and utilized as a powerful label probe for constructing a highly sensitive CL imaging immunosensor targeting disease biomarkers with excellent performance. This research offers a universal strategy for enhancing the sensitivity of CL imaging immunoassays and further expands the application of PBA nanozymes.