It is necessary to develop rapid, simple and accurate detection method for Escherichia coli (E. coli) due to its widely distributed pathogenic bacteria. Herein, we prepared AgBr nanoparticles (NPs) ...anchored 3D nitrogen-doped graphene hydrogel (3DNGH) nanocomposites with an exceptionally large accessible surface by a simple hydrothermal approach. The as-prepared 3DNGH porous nanocomposite not only showed better conductivity than that of 3D graphene due to introducing nitrogen element into graphene framework, but also provided a high loading volume for immobilizing luminol. Meanwhile the anchored AgBr NPs served as the catalyst can effectively enhance the ECL behavior of luminol. And the resulting luminol/AgBr/3DNGH exhibited more excellent ECL performances, which was about 2, 3, 8 times enhanced respectively, comparing to luminol/AgBr/3DGH, luminol/3DNGH and luminol/AgBr/2DNG. Further, the multifunctional nanoarchitecture was used as the all-solid-state ECL platform for fabricating Escherichia coli aptasensors via glutaraldehyde as crosslinking agent between amine-functionalized E. coli aptamer and luminol/AgBr/3DNGH. Based on the steric hindrance mechanism that E.coli can significantly decrease the ECL intensity, the proposed aptasensor displayed a linear response for E.coli in the range from 0.5 to 500 cfu/mL with an extremely low detection limit of 0.17 cfu/mL (S/N). In addition, this ECL aptasensor possessed great advantages including the simple operation process, low-cost and sensitivity, which provided a promising approach for the E.coli detection in biomedical, food detection and environmental analysis.
•AgBr anchored 3D nitrogen-doped graphene hydrogel were prepared.•Nitrogen doping intrinsically improved the conductivity of 3D graphene.•The 3D porous structure provided a high loading volume for luminol.•AgBr served as the catalyst to amplify ECL performance of luminol.•All-solid-state luminol-ECL Escherichia coli aptasensors were fabricated.
Sensitive detection methods for nitrite (NO2 –) and nitrate (NO3 –) ions are essential to understand the nitrogen cycle and for environmental protection and public health. Herein, we report a ...detection method that combines ion-chromatographic separation of NO2 – and NO3 –, on-line photochemical conversion of these ions to peroxynitrite (ONOO–) by irradiation with a 222 nm excimer lamp, and chemiluminescence from the reaction between luminol and ONOO–. The detection limits for NO2 – and NO3 – were 0.01 and 0.03 μM, respectively, with linear ranges of 0.010–2.0 and 0.10–3.0 μM, respectively, at an injection volume of 1 μL. The results obtained by the proposed method for seawater analysis corresponded with those of a reference method (AutoAnalyzer based on the Griess reaction). As luminol chemiluminescence can measure ONOO– at picomolar concentrations, our method is expected to be able to detect NO2 – and NO3 – at picomolar concentrations owing to the high conversion ratio to ONOO– (>60%), assuming that contamination and background chemiluminescence issues can be resolved. This method has the potential to emerge as an innovative technology for NO2 – and NO3 – detection in various samples.
The accumulation of pesticide residues poses a significant threat to the health of people and the surrounding ecological systems. However, traditional methods are not only costly but require ...expertise in analysis. An electrochemiluminescence (ECL) aptasensor was developed using chitosan and molybdenum disulfide (CTS-MoSsub.2), along with acetylene black (AB@CTS) for the rapid detection of malathion residues. Due to the weak interaction force, simple composite may lead to uneven dispersion; MoSsub.2 and AB were dissolved in CTS solution, respectively, and utilized the biocompatibility of CTS to interact with each other on the electrode. The MoSsub.2 nanosheets provided a large specific surface area, enhancing the utilization rate of catalytic materials, while AB exhibited excellent conductivity. Additionally, the dendritic polylysine (PLL) contained numerous amino groups to load abundant luminol to catalyze hydrogen peroxide (Hsub.2Osub.2) and generate reactive oxygen species (ROS). The proposed ECL aptasensor obtained a low detection limit of 2.75 × 10sup.−3 ng/mL (S/N = 3) with a good detection range from 1.0 × 10sup.−2 ng/mL to 1.0 × 10sup.3 ng/mL, demonstrating excellent specificity, repeatability, and stability. Moreover, the ECL aptasensor was successfully applied for detecting malathion pesticide residues in authentic samples with recovery rates ranging from 94.21% to 99.63% (RSD < 2.52%). This work offers valuable insights for advancing ECL sensor technology in future applications.
Chemiluminescence (CL) is an important method for quantification and analysis of various macromolecules. A wide range of CL agents such as luminol, hydrogen peroxide, fluorescein, dioxetanes and ...derivatives of oxalate, and acridinium dyes are used according to their biological specificity and utility. This review describes the application of luminol chemiluminescence (LCL) in forensic, biomedical, and clinical sciences. LCL is a very useful detection method due to its selectivity, simplicity, low cost, and high sensitivity. LCL has a dynamic range of applications, including quantification and detection of macro and micromolecules such as proteins, carbohydrates, DNA, and RNA. Luminol-based methods are used in environmental monitoring as biosensors, in the pharmaceutical industry for cellular localization and as biological tracers, and in reporter gene-based assays and several other immunoassays. Here, we also provide information about different compounds that may enhance or inhibit the LCL along with the effect of pH and concentration on LCL. This review covers most of the significant information related to the applications of luminol in different fields.
High-intensity focused ultrasound pretreatment as a non-invasive method could generate H2O2 and O2•− in situ, triggering and boosting the ECL signal of luminol-O2 system. Meanwhile, 1T/2H MoS2 could ...catalyze the H2O2 formed in situ to enhance the ECL response.
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•A novel strategy combining ultrasound with nanomaterial was designed.•High-intensity focused ultrasound (HIFU) could generate H2O2 and O2•− in situ.•1T/2H MoS2 could catalyze the H2O2 to boost the ECL signal of luminol-O2 system.•The ECL biosensor was successfully applied to the determination of miRNA-155.
In the luminol-O2 ECL system, O2 as an endogenous coreactant has the advantages of non-toxicity and stability. Improving the efficiency to generate radicals of O2 is a challenge currently. In this work, a strategy combining physical method - ultrasound and nanomaterial with unique physicochemical properties was designed to enhance the ECL signal of luminol-O2 system. Specifically, high-intensity focused ultrasound (HIFU) pretreatment as a non-invasive method could generate ROS (H2O2, O2•−, OH•, 1O2) in situ, triggering and boosting the ECL signal of luminol. In addition, 1T/2H MoS2 with excellent catalytic activity could catalyze the H2O2 produced in situ, accelerate the oxidation of luminol and further enhance the ECL response. At the same time, combined with the catalytic hairpin assembly (CHA) reaction, the constructed ECL biosensing platform showed excellent performance for the detection of miRNA-155. The concentration range of 0.1 fM ∼ 1 nM with the detection limit as low as 0.057 fM were obtained. Furthermore, the ECL biosensor was also successfully applied to the determination of miRNA-155 in human serum samples. The established ECL sensing platform opens up a promising method for the detection of clinical biomarkers.
The preparation of self-assembled DNA nanostructure with different sizes and shapes has been one of the most promising research areas in recent years, while the application of these DNA ...nanostructures in biosensors is far from fully developed. Here, we presented a novel carrier system to construct an electrochemiluminescence (ECL) aptasensor for ultrasensitive determination of lipopolysaccharides (LPS) on the basis of self-assembled tetrahedron DNA dendrimers. Doxorubicin (Dox), a well-known intercalator of double stranded DNA (dsDNA), was conjugated with the ECL luminophore of N-(aminobutyl)-N-(ethylisoluminol) (ABEI) to form a new type of ECL indicators (Dox-ABEI), which could noncovalently attach to dsDNA through intercalation. Based on this property, self-assembled tetrahedron DNA dendrimers were employed as an efficient nanocarrier to achieve a high loading efficiency for Dox-ABEI with significantly amplified ECL signal output. Streptavidin (SA) and biotin, a typical ligand–receptor pair, has been chosen to anchor the tetrahedron DNA dendrimers on the electrode surface. Moreover, by converting LPS content into DNA output, catalyzed hairpin assembly (CHA) target recycling signal amplification strategy was also adopted to enhance the sensitivity of the ECL aptasensor. With combining the loading power of the tetrahedron DNA dendrimers for ECL indicators, the inherent high sensitivity of ECL technique and target recycling for signal amplification, the proposed strategy showed a detection limit of 0.18 fg/mL for LPS.
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The anodic oxygen evolution reaction is a well-acknowledged side reaction in traditional aqueous electrochemiluminescence (ECL) systems due to the generation and surface aggregation ...of oxygen at the electrode, which detrimentally impacts the stability and efficiency of ECL emission. However, the effect of reactive oxygen species generated during water oxidation on ECL luminophores has been largely overlooked. Taking the typical luminol emitter as an example, herein, we employed NiIr single-atom alloy aerogels possessing efficient water oxidation activity as a prototype co-reaction accelerator to elucidate the relationship between ECL behavior and water oxidation reaction kinetics for the first time. By regulating the concentration of hydroxide ions in the electrolyte, the electrochemical oxidation processes of both luminol and water are finely tuned. When the concentration of hydroxide ions in electrolyte is low, the kinetics of water oxidation is attenuated, which limits the generation of oxygen, effectively mitigates the influence of oxygen accumulation on the ECL strength, and offers a novel perspective for harnessing side reactions in ECL systems. Finally, a sensitive and stable sensor for antioxidant detection was constructed and applied to the practical sample detection.
An ultrasensitive sandwich-type electrochemiluminescence (ECL) immunosensor was developed for detection of prostate specific antigen (PSA) using an amplification strategy based on ZnO ...nanorods-l-cysteine-luminol nanocomposites and the biotin-streptavidin system. The biotin-streptavidin system served as a capture probe to increase the number of antibodies. ZnO nanorods not only acted as a nanocarrier that increased the number of luminol molecules and secondary antibodies, but also enhanced the ECL signal of luminol-H2O2 system by promoting H2O2 decomposition, which can further increase ECL intensity. Under optimized conditions, the proposed immunosensor demonstrated excellent analytical performance with a wide linear detection range of 0.03 pg mL−1 to 30 ng mL−1 and a detection limit of 0.01 pg mL−1 (the detection limit in real samples was 0.021 pg mL−1). This method exhibited excellent stability, reproducibility, and selectivity. In addition, the results of PSA determinations in human serum samples obtained using the proposed immunosensor were consistent with data collected using the commercial chemiluminescence immunoassay analyzer.
Schematic illustration of fabrication of the proposed immunosensor. Display omitted
•A sandwich-type ECL immunosensor has been proposed for PSA detection.•Clinical serum samples was analyzed using this proposed immunosensor and correlation coefficient of 0.995 was obtained.•The detection limit of this immunosensor can reach 10 fg mL−1.
A sensitive electrochemiluminescent immunoassay for alkaline phosphatase (ALP) using p-nitrophenyl phosphate (PNPP) as substrate based on the electrochemiluminescence resonance energy transfer ...(ECRET) is developed. Luminol-doped silica nanoparticles (luminol-SiNPs) are prepared by water/oil (W/O) microemulsion method. PNPP convertes to p-nitrophenol (PNP) in the presence of ALP, which results in the absorption peak shifting from 360 nm to 450 nm. Herein the spectral overlap between absorption spectrum of PNP and electrochemiluminescence (ECL) spectrum of luminol-SiNPs (425 nm) makes energy transfer occur from luminol-SiNPs to PNP. In the optimized conditions, a linear relationship was obtained using this ECRET method at the concentration of ALP from 5 to 50 U/L (r = 0.9905) and with the limit of detection (LOD) of 0.8 U/L. This ECRET method exhibits sufficient specificity for ALP over other enzymes such as horseradish peroxidase, trypsin and lysozyme.
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•Electrochemiluminescence resonance energy transfer (ECRET) immunoassay for alkaline phosphatase from 5 to 50 U/L.•Spectral overlap between absorption spectrum of p-nitrophenol (PNP) and ECL spectrum of luminol-SiNPs.•ECRET occurs from luminol-SiNPs to PNP and makes electrochemiluminescence intensity be quenched.•ALP converts p-nitrophenyl phosphate (PNPP) to PNP and results the absorption peak to shift from 360 nm to 450 nm.
Designing the catalytic interface that preferentially attracts reactants is highly desirable for amplifying chemiluminescence (CL) emission. Herein, to boost the generation of reactive oxygen species ...(ROS) from dissolved O2 molecule, flower-like cobalt hydroxide (f-Co(OH)2) based catalytic interface with hierarchical and porous architecture were in situ created in the coexistence of BSA and Co2+. Benefiting from the oxidase-like catalysis capability and the unique microstructure of f-Co(OH)2, ROS was efficiently produced. Meanwhile, the capping ligands of BSA endowed the interface with the capability of enriching functionality through the interaction between BSA and luminol. 100-fold CL enhancement was achieved using the as-prepared catalytic interface compared with the classical luminol-Co2+ or luminol-BSA system. Moreover, the proposed catalytic amplification mechanism could be extended to the different proteins such as lysozyme, protamine, thrombin, papain. Based on the quenching effect on CL, a sensitive sensing platform was constructed for the determination of ascorbic acid with satisfied results. Our finding provided a novel “all-in-one” route to design the catalytic interface for amplifying CL emission.
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