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1.
Anal Chem ; 95(2): 570-574, 2023 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-36596251

RESUMO

Cathodic electrochemiluminesence (ECL) microscopy based on luminol analog L012 was originally established to implement the imaging of a single nanotube and nucleolin on a single tumor cell. This microscopy utilizes multiwalled carbon nanotubes (MWCNTs) as advanced coreactant accelerators to efficiently convert dissolved oxygen (O2) and H2O2 into reactive oxygen species (ROS) due to excellent electrocatalytic properties. The produced ROS could oxide L012 into an excited state of L012 leading to a bright cathodic ECL illumination, thereby promoting ECL imaging of MWCNTs at a low triggering potential. After being modified with AS1411 aptamers, MWCNTs@AS1411 probes were incubated with tumor cells for specific ECL imaging of nucleolin on the plasma membrane, which permits cathodic ECL microscopy for label-free bioassays without ECL tags. The L012-based cathodic ECL microscopy with a moderate operating potential and label-free characteristics provides a universal approach in single nanomaterial and single-cell imaging and analyses.


Assuntos
Técnicas Biossensoriais , Nanotubos de Carbono , Análise de Célula Única , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Peróxido de Hidrogênio , Medições Luminescentes/métodos , Luminol , Microscopia , Espécies Reativas de Oxigênio , Análise de Célula Única/métodos
2.
ACS Appl Mater Interfaces ; 15(3): 3804-3811, 2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36632668

RESUMO

Luminol is a classic electrochemiluminescence (ECL) luminophore. The luminol-O2 ECL system suffers from a problem, that is, the conversion rate of dissolved O2 into reactive oxygen species (ROS) is low. In this work, we used high-intensity focused ultrasound (HIFU) pretreatment combined with Ti3C2-TiO2 to construct a highly sensitive luminol-O2 ECL system for the specific detection of polynucleotide kinase (PNK) first. On the one hand, HIFU generated ROS in situ as a coreactant via the cavitation effect to boost the luminol emission. On the other hand, Ti3C2-TiO2 was prepared in situ via Ti3C2 as a reducing agent, and it can aggregate and catalyze ROS generated in situ by HIFU. Moreover, the Ti on the Ti3C2-TiO2 surface could bind to phosphate groups through chelation, thereby realizing highly specific detection of PNK. The sensor has a linear relationship range of 1.0 × 10-5 to 10.0 U mL-1, and the limit of detection is 1.48 × 10-7 U mL-1, which is superior to most existing methods. The sensor performance in HeLa cell lysate was measured with a satisfactory result. The designed ECL biosensor has potential applications in biological analysis and clinical diagnosis.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Humanos , Luminol , Titânio , Polinucleotídeo 5'-Hidroxiquinase , Espécies Reativas de Oxigênio , Células HeLa , Medições Luminescentes/métodos , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Limite de Detecção
3.
Anal Chem ; 95(2): 1065-1073, 2023 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-36542087

RESUMO

Protein aggregation has been found in a wide range of neurodegenerative protein-misfolding diseases. The demand for in vivo technologies to identify protein aggregation is at the leading edge for the pathogenic study, diagnostic development, and therapeutic intervention of these devastating disorders. Herein, we report a series of luminol analogues to construct a facile chemiluminescence (CL)-based approach for in vivo detection and imaging of ß-sheet protein aggregates. The synthesized compounds exhibited a distinct chemiluminescent response with long emission wavelengths toward reactive oxygen species under physiological conditions and displayed signal amplification in the presence of ß-sheet protein aggregates, including α-synuclein, ß-amyloid, and tau. Among them, CyLumi-3 was further evaluated as a chemiluminescent probe in preclinical models. By intravenous administration into the model mice via the tail vein, in vivo CL imaging noninvasively detected the specific CL of the probe targeting the α-synuclein aggregates in the brains of living mice. Based on its structural characteristics, CyLumi-3 can readily interact with α-synuclein aggregates with significantly enhanced fluorescence and can identify α-synuclein aggregates in vivo via distinctive CL amplification, which could pave the way for a more comprehensive understanding of protein aggregation in preclinical studies and would provide new hints for developing small-molecule chemiluminophores for protein aggregates.


Assuntos
Agregados Proteicos , alfa-Sinucleína , Camundongos , Animais , alfa-Sinucleína/química , Conformação Proteica em Folha beta , Luminol , Espécies Reativas de Oxigênio/metabolismo
4.
Biosens Bioelectron ; 222: 114996, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36521203

RESUMO

Here, a novel and portable machine learning-assisted smartphone-based visual molecularly imprinted ratiometric electrochemiluminescence (MIRECL) sensing platform was constructed for highly selective sensitive detection of 2,4-Dichlorophenoxyacetic acid (2,4-D) for the first time. Te doped CdS-coated Mn3O4 (Te-CdS@Mn3O4) with catalase-like activity served as cathode-emitter, while luminol as anode luminophore accompanied H2O2 as co-reactant, and Te-CdS@Mn3O4 decorated molecularly imprinted polymers (MIPs) as recognition unit, respectively. Molecular models were constructed and MIP band and binding energies were calculated to elucidate the luminescence mechanism and select the best functional monomers. The peroxidase activity and the large specific surface area of Mn3O4 and the electrochemical effect can significantly improve the ECL intensity and analytical sensitivity of Te-CdS@Mn3O4. 2,4-D-MIPs were fabricated by in-situ electrochemical polymerization, and the rebinding of 2,4-D inhibits the binding of H2O2 to the anode emitter, and with the increase of the cathode impedance, the ECL response of Te-CdS@Mn3O4 decreases significantly. However, the blocked reaction of luminol on the anode surface also reduces the ECL response. Thus, a double-reduced MIRECL sensing system was designed and exhibited remarkable performance in sensitivity and selectivity due to the specific recognition of MIPs and the inherent ratio correction effect. Wider linear range in the range of 1 nM-100 µM with a detection limit of 0.63 nM for 2,4-D detection. Interestingly, a portable and visual smartphone-based MIRECL analysis system was established based on the capture of luminescence images by smartphones, classification and recognition by convolutional neural networks, and color analysis by self-developed software. Therefore, the developed MIRECL sensor is suitable for integration with portable devices for intelligent, convenient, and fast detection of 2,4-D in real samples.


Assuntos
Técnicas Biossensoriais , Impressão Molecular , Impressão Molecular/métodos , Smartphone , Luminol/química , Peróxido de Hidrogênio , Medições Luminescentes/métodos , Técnicas Biossensoriais/métodos , Limite de Detecção , Polímeros Molecularmente Impressos , Ácido 2,4-Diclorofenoxiacético , Técnicas Eletroquímicas/métodos
5.
Talanta ; 254: 124183, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36512973

RESUMO

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.


Assuntos
Peróxido de Hidrogênio , Luminol , Luminol/química , Peróxido de Hidrogênio/química , Cobre , Luminescência , Limite de Detecção , Medições Luminescentes/métodos , Metais , Concentração de Íons de Hidrogênio
6.
Ultrason Sonochem ; 92: 106264, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36521209

RESUMO

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 âˆ¼ 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.


Assuntos
Técnicas Biossensoriais , MicroRNAs , Humanos , Luminol/química , Molibdênio , Peróxido de Hidrogênio/química , Limite de Detecção , Medições Luminescentes/métodos , Técnicas Biossensoriais/métodos , Catálise , Técnicas Eletroquímicas/métodos
7.
Anal Chem ; 94(50): 17625-17633, 2022 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-36475634

RESUMO

Luminol is one of the most widely used electrochemiluminescence (ECL) reagents, yet the detailed mechanism and kinetics of the electrochemical oxidation of luminol remain unclear. We propose a model that describes the electrochemical oxidation of luminol as multiple electron transfer reactions followed by an irreversible chemical reaction, and we applied a finite element method simulation to analyze the electron transfer kinetics in alkaline solutions. Although negligible at higher pH values, the adsorption of luminol on the glassy carbon electrode became noticeable in a solution with pH = 12. Additionally, various types of adsorption behaviors were observed for luminol derivatives and analogues, indicating that the molecular structure affected not only the oxidation but also the adsorption process. The adsorption effect was analyzed through a model with a Langmuir isotherm to show that the saturated surface concentration as well as the reaction kinetics increased with decreasing pH, suggesting a competition for the active sites between the molecule and OH-. Moreover, we show that the ECL intensity could be boosted through the adsorption effect by collecting the ECL intensity generated through the electrochemical oxidation of luminol and a luminol analogue, L012, in a solution with pH = 13. In contrast with luminol, a significant adsorption effect was observed for L012 at pH = 13, and the ECL intensity was enhanced by the adsorbed species, especially at higher scan rates. The magnitude of the enhancement of the ECL intensity matched well with the simulation using our model.


Assuntos
Técnicas Biossensoriais , Luminol , Luminol/química , Carbono , Adsorção , Luminescência , Eletrodos , Medições Luminescentes/métodos , Técnicas Eletroquímicas/métodos
8.
Anal Chem ; 94(51): 17787-17794, 2022 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-36520819

RESUMO

Gastric cancer is a malignant tumor, and its early diagnosis remains challenging due to the lack of simple and sensitive detection methods and specific biomarkers. In this work, to improve the detection reliability, we developed a dual-mode detection strategy for the detection of two biomarkers associated with it. First, an N- and S-doped carbon dots-N-rich porous carbon nanoenzyme (N/S-CDs@NC) was prepared by a two-step pyrolysis of thiourea-penetrated zinc-based zeolite imidazole framework. It was then combined with the 3,3',5,5'-tetramethylbenzidine-H2O2 system for the colorimetric detection of d-amino acids (i.e., d-proline (d-Pro) and d-alanine (d-Ala)) in saliva, based on d-amino acid oxidase catalyzing d-amino acid oxidation to produce H2O2. In this way, the low detection limits (S/N = 3) of d-Pro and d-Ala were 0.14 and 0.35 µM, respectively. Furthermore, N/S-CDs@NC was combined with the luminol-H2O2 electrochemiluminescence (ECL) system and magnetic immune accumulation/separation strategy to detect the carcinoembryonic antigen (CEA) in serum. The porous N/S-CDs@NC could facilitate participant contact, promote the generation of hydroxyl radical (•OH), and electrostatically attract •OH, thereby significantly amplifying the ECL signal of luminol and improving the signal stability. Thus, the detection mode showed considerable sensitivity and selectivity, with a low detection limit of 0.26 pg mL-1. The strategy proposed in this work can also be used for the detection of other disease markers by substituting the recognition elements, thus having good application potential.


Assuntos
Técnicas Biossensoriais , Neoplasias Gástricas , Humanos , Carbono/química , Luminol/química , Antígeno Carcinoembrionário , Aminoácidos , Neoplasias Gástricas/diagnóstico , Colorimetria , Porosidade , Peróxido de Hidrogênio , Reprodutibilidade dos Testes , Catálise , Limite de Detecção , Medições Luminescentes/métodos , Técnicas Biossensoriais/métodos
9.
Mikrochim Acta ; 189(12): 473, 2022 11 24.
Artigo em Inglês | MEDLINE | ID: mdl-36434474

RESUMO

Electrospun nanofibers containing CdTe@ZnNi-metal-organic frameworks (CdTe@ZnNi-MOF NFs) were used for the first time in luminol-O2 electrochemiluminescence (ECL) system to construct ECL sensor for chlorpyrifos (CPF) detection. Firstly, CdTe@ZnNi-MOF NFs obtained by blending method was used to modify the surface of a glassy carbon electrode, and then, the proposed solid-state ECL sensor was constructed by dropping luminol onto the surface of nanofiber benefiting from chitosan (CTS) viscosity. CdTe@ZnNi-MOF NFs with its large surface area and porosity can be used not only as luminol carrier but also as co-reaction promoter of the ECL system. The ECL sensor obtained satisfactory results in weakly alkaline solution under the synergistic action of CdTe@ZnNi-MOF NFs and luminol. The constructed ECL sensor can effectively detect CPF in the range 1.0 × 10-14-1.0 × 10-9 M, and the detection limit was 6.23 × 10-17 M (3σ/m). The constructed sensor was simple and sensitive, and can be used for the determination of CPF in vegetable samples. It not only broadened the application of MOFs in the field of ECL but also provided a new idea for expanding the application of the luminol-O2 system.


Assuntos
Compostos de Cádmio , Clorpirifos , Estruturas Metalorgânicas , Nanofibras , Pontos Quânticos , Luminol , Medições Luminescentes/métodos , Telúrio
10.
Anal Methods ; 14(46): 4767-4774, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36416105

RESUMO

Cytochrome c (cyt c) plays a critical role in mitochondrial respiratory chain, whose absence is detrimental to electron transport and reduce adenosine triphosphate. For ultrasensitive detection of cyt c, sheet-like covalent organic frameworks (COFs) were prepared by orderly accumulation of 1,3,5-benzenetricarboxaldehyde (BTA) and p-phenylenediamine (PDA), and further grafted with N-(4-aminobutyl)-N-ethylisoluminol (ABEI) - an electrochemiluminescence (ECL) emitter. Specifically, the morphology and structure of the COFs-ABEI were mainly characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) analysis, and X-ray photoelectron spectroscopy (XPS). In parallel, the optical properties of the emitter were certified by UV-vis absorbance spectroscopy, Fourier infrared spectroscopy (FTIR), fluorescence (FL), and ECL measurements, showing 2.25-time enhanced ECL efficiency over pure ABEI, coupled by illustrating the interfacial electron transport mechanism. On the above foundation, a label-free "signal off" ECL biosensor was constructed by virtue of the specific immune recognition between the aptamer of the target cyt c with its capture DNA (cDNA) anchored on the biosensing platform, exhibiting a wider linear range of 1.00 fg mL-1-0.10 ng mL-1 (R2 = 0.998) and a lower limit of detection (LOD) down to 0.73 fg mL-1. This work offers some constructive guidelines for sensitive bioassays of disease-related biomarkers in the clinical field.


Assuntos
Citocromos c , Estruturas Metalorgânicas , Luminol , Aminação , Transporte de Elétrons
11.
Anal Bioanal Chem ; 414(29-30): 8309-8315, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36239751

RESUMO

Electrochemiluminescence (ECL) of luminol is a well-established methodology in analytical chemistry and bioimaging. Developing novel strategies to enhance the ECL signal of this model emitter is a challenging but rewarding task. In this work, we introduced the high-intensity focused ultrasound (HIFU), as a pretreatment means and a non-invasive way to trigger and boost the ECL signal with a 40-fold significant enhancement in the luminol-O2 system without the addition of exogenous co-reactants. The superoxide anion (O2-•) generated in situ by HIFU was the key initiator for boosting the ECL emission as demonstrated in this study for the first time. This promising co-reactant-free strategy could find potential applications for ultrasensitive ECL detection in the analysis of complex biological entities.


Assuntos
Técnicas Biossensoriais , Luminol , Técnicas Eletroquímicas/métodos , Técnicas Biossensoriais/métodos , Medições Luminescentes/métodos , Limite de Detecção
12.
Anal Chem ; 94(44): 15448-15455, 2022 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-36279477

RESUMO

The innovative assembly of luminescent hydrogen-bonded organic frameworks (HOFs) into multifunctional optical sensors is of great significance for developing advanced materials. Herein, we report a facile room-temperature synthesis strategy for the luminol HOF modified by Tb3+ (Lumi-HOF@Tb) and featuring sensitive chemiluminescence and fluorescence characteristics. Lumi-HOF@Tb is further pioneered as a dual-signal sensor for selective detection of α-glucosidase, a type of enzyme that plays a crucial role in the digestion of carbohydrates, and screening of its inhibitors. The sensor is constructed by combining the dual optical characteristics of luminol from the HOF and lanthanide ion assistance. From the hydrolysis of α-glucosidase and the 4-nitrophenyl-α-d-glucopyranoside (pNGP) substrate emerges the fluorescent luminol-p-nitrophenol (pNP) complex at 466 nm and changes the inner filter absorption to recover Tb3+ characteristic fluorescence at 546 nm; luminol also produces a chemiluminescence signal driven by H2O2 from additional glucose oxidase-catalyzed hydrolysis of α-d-glucose. Fluorescence and chemiluminescence assays for α-glucosidase activity have therefore been established and exhibit detection limits as low as 0.04 and 0.005 U L-1, respectively. This study not only presents the possibility of Ln3+-HOF-based sensors as intelligent optical materials by integration of fluorescence and chemiluminescence techniques but also demonstrates great potential for future applications in biosensing.


Assuntos
Luminol , alfa-Glucosidases , Luminescência , Peróxido de Hidrogênio , Glucose Oxidase , Limite de Detecção
13.
Anal Biochem ; 659: 114958, 2022 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-36273622

RESUMO

The percentage of glycated hemoglobin (HbA1c) in total hemoglobin (Hb) is an important index for the diagnosis of Type II diabetes (T2D) because it reflects the long-term glucose level in blood. Herein, employing a one-pot co-reduction approach using glutathione (GSH) as structure-directing agent, a cluster-like AuAg nanoparticle (AuAg NPs) material was synthesized, therefore an electrochemiluminescence (ECL) aptamer-sensor for HbA1c detection was developed based on functionalized electrode with this material. Meanwhile, the quantitative determination of total Hb was realized based on the quenching effect of Hb on the fluorescence (FL) of luminol. Under compatible conditions, the results of both indexes can be satisfactorily acquired. This multimodal detection system has a good linear response toward Hb from 0.1 to 2.5 µM and HbA1c from 0.005 to 0.5 µM. The blood test proves this strategy is capable of accurate Hb and HbA1c detection, thus to obtain the percentage of HbA1c in total Hb (HbA1c%), which has the potential application for clinical diagnosis of diabetes mellitus.


Assuntos
Diabetes Mellitus Tipo 2 , Humanos , Diabetes Mellitus Tipo 2/diagnóstico , Luminol , Eletrodos , Testes Hematológicos
14.
Mikrochim Acta ; 189(11): 423, 2022 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-36255523

RESUMO

A novel ratiometric electrochemiluminescence (ECL) system based on gold nanostars (AuNSs) support was constructed for the determination of hypotonicity-induced ATP release from HepG2 cells. AuNS@Lu nanoprobe was used as anodic luminophore and K2S2O8 as cathodic luminophore as well as anodic co-reactant. AuNS with the large specific surface was adopted to adsorb plentiful luminol to form solid-state probe and as affinity support to immobilize ATP aptamer (Apt). The obtained nanocomposite (Apt-AuNS@Lu) generated a strong ECL signal at + 0.4 V (vs. Ag/AgCl) with co-reactant K2S2O8, because of excellent conductivity and catalytic activity of AuNS. Furthermore, graphene oxide was reduced onto indium tin oxide (ITO) electrodes to facilitate the electron transfer. Following, polydopamine (PDA) film was formed via self-polymerization, improving stability and adhesion of the electrode surface. To immobilize ATP capture aptamer (AptC), abounding AuNSs were attached to RGO/PDA surface. When the sensor was incubated in the mixture solution of Apt-AuNS@Lu and target ATP, the ECL signal of Apt-AuNS@Lu increased with the increase of ATP concentration, meanwhile, the signal of K2S2O8 declined. The ratio of the two luminophores was used for the quantitative determination of ATP. The linear range was 5 to 250 nM, and the limit of detection was 1.4 nM at (3σ)/S. The method was successfully applied to analyze ATP release from HepG2 cells stimulated by 0.45% NaCl hypotonic solution. The results showed that the release kinetics profile of ATP had a sigmoidal shape with rapid release within 10 min and then slowed. Compared to the isotonic groups, the intracellular ATP concentration was 3.7 ± 0.3 µM (n = 3) decreasing by 40.3% and the extracellular was 23.4 ± 1.2 nM (n = 3) increasing by 9.2 times in the hypotonicity for 10 min, which showed ATP release from cells and good agreement with commercial ELISA test. The proposed strategy would be beneficial to broadening application of ECL technology in studying cell biological functions.


Assuntos
Luminol , Nanopartículas Metálicas , Medições Luminescentes , Cloreto de Sódio , Soluções Hipotônicas , Ouro , Trifosfato de Adenosina/análise
15.
Anal Chim Acta ; 1232: 340478, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36257748

RESUMO

In view of the optimal catalytic efficiency (∼100%), single-atom site catalysts are being widely exploited in a range of areas including organic synthesis, energy conversion, environmental remediation, biotherapy, etc. However, low loading ratio of the unitary active sites on single-atom site catalysts dramatically hinders the remarkable improvement of their catalytic activity. Hereby, a facile low-temperature reduction protocol was adopted for synthesizing CoN4-supported Co2N metal clusters on graphitic carbon nitride, which show the remarkably superior chemiluminescent (CL) catalytic capacity than some reported pure single-atom site catalysts. Nitrogen-encapsulated Co2N clusters coupled with isolated Co-N4 moieties (Co2N@Co-N4) endowed the synergetic catalysts with high Co content of 53.2 wt%. Through X-ray absorption spectroscopy, the synergetic active sites (Co2N@Co-N4) afforded the CoN4-supported Co2N clusters with the remarkable catalytic activity for accelerating the decomposition of H2O2 to produce extensive superoxide radical anion rather than singlet oxygen or hydroxyl radical. Therefore, the CoN4-supported Co2N clusters possessed the superb enhancement effect on luminol-H2O2 CL reaction by ∼22829 times. The CoN4-supported Co2N clusters were utilized as signal probes to establish a CL immunochromatographic assay (ICA) platform for quantitating mycotoxins. Herein, aflatoxin B1 was employed as a mode analyte and the limit of detection was as low as 0.33 pg mL-1 (3σ). As a proof-of-principle work, the developed ICA protocol was successfully employed on the detection of aflatoxin B1 spiked in Angelica dahurica and Ganoderma lucidum with acceptable recoveries of 84.0-107.0%. The ideal practicability of the work elucidates that CoN4-supported Co2N clusters showed a new perspective for developing the sensitive CL biosensing.


Assuntos
Radical Hidroxila , Luminol , Luminol/química , Superóxidos , Oxigênio Singlete/química , Peróxido de Hidrogênio/química , Limite de Detecção , Aflatoxina B1 , Metais , Nitrogênio , Imunoensaio
16.
Proc Natl Acad Sci U S A ; 119(43): e2207693119, 2022 10 25.
Artigo em Inglês | MEDLINE | ID: mdl-36252039

RESUMO

Although the onset time of chemical reactions can be manipulated by mechanical, electrical, and optical methods, its chemical control remains highly challenging. Herein, we report a chemical timer approach for manipulating the emission onset time of chemiluminescence (CL) reactions. A mixture of Mn2+, NaHCO3, and a luminol analog with H2O2 produced reactive oxygen species (ROS) radicals and other superoxo species (superoxide containing complex) with high efficiency, accompanied by strong and immediate CL emission. Surprisingly, the addition of thiourea postponed CL emission in a concentration-dependent manner. The delay was attributed to a slow-generation-scavenging mechanism, which was found to be generally applicable not only to various types of CL reagents and ROS radical scavengers but also to popular chromogenic reactions. The precise regulation of CL kinetics was further utilized in dynamic chemical coding with improved coding density and security. This approach provides a powerful platform for engineering chemical reaction kinetics using chemical timers, which is of application potential in bioassays, biosensors, CL microscopic imaging, microchips, array chips, and informatics.


Assuntos
Luminescência , Luminol , Peróxido de Hidrogênio , Medições Luminescentes/métodos , Espécies Reativas de Oxigênio , Superóxidos , Tioureia
17.
ACS Sens ; 7(10): 3085-3093, 2022 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-36222744

RESUMO

A novel electrochemiluminescence (ECL) amplification strategy was established aiming to overcome the inherent shortcomings of the current oxygen (O2) coreactant ECL systems. Macrocyclic Schiff base Fe complexes were rationally designed as a novel integrated ECL emitter by iminium linkage between N-(4-aminobutyl)-N-ethylisoluminol (ABEI) and 1,10-phenanthroline-2,9-dicarbaldehyde (PDL) and postmetalation of the macrocyclic Schiff base. Covalently combining luminophore ABEI with a catalytic center endowed the novel ECL emitter with both remarkable redox electrocatalytic properties and significantly enhanced ECL efficiency. The high content of ferrous iron and the dominantly active low-spin Fe state greatly contributed to the inherent catalytic activity for O2 activation. The rational modification of luminophore optimized the spatial distribution and simultaneously shortened the species transport distance of coreactant radicals generated in situ from dissolved O2, resulting in significantly self-enhanced ECL efficiency. Neomycin, which posed a growing threat to aquatic biodiversity and environmental safety, as the model antibiotic was successfully detected with a detection limit of 0.21 pM (S/N = 3), clarifying a promising application prospect of this new luminophore-embedded ECL amplification strategy in biological analysis and environmental monitoring.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Luminol , Medições Luminescentes/métodos , Técnicas Biossensoriais/métodos , Limite de Detecção , Bases de Schiff , Neomicina
18.
Anal Chem ; 94(41): 14394-14401, 2022 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-36198129

RESUMO

Acute myocardial infarction (AMI)-related microRNAs (miRNAs) in circulating blood have been proved as promising biomarkers for AMI diagnosis. The detection of these miRNAs at ultralow levels usually requires nucleic acid amplification strategies to improve the sensitivity at the cost of time. Given that the first hour after an AMI attack is the golden time for saving AMI patients' lives, shortening the time of ultrasensitive miRNA analysis is of great significance for clinical AMI diagnosis. Toward this goal, here we present a direct electrochemiluminescence (ECL) sensing strategy for fast and ultrasensitive miRNA detection, circumventing the time-consuming signal amplification steps. Target miRNAs are directly hybridized with two probe strands that are attached to a covalently hemin-modified spherical nucleic acid enzyme (SNAzyme) and a truncated triangular pyramid DNA nanoplatform on the electrode, respectively. Both of them improve the ECL signal and meanwhile reduce the background, thereby remarkably promoting the detection sensitivity of target miRNAs. It enables the rapid detection of an AMI-related miRNA (miR-499) at 10 aM in human serum within 30 min using the SNAzyme-catalyzed luminol-H2O2 ECL reaction. This sensing strategy is then utilized for AMI diagnosis via probing endogenous miR-499 in patients' circulating blood with endogenous miR-16 as an intrinsic reference, showing a significant difference (P < 0.001) between the miR-499 levels of patients and the healthy.


Assuntos
MicroRNA Circulante , DNA Catalítico , MicroRNAs , Infarto do Miocárdio , Biomarcadores , Hemina , Humanos , Peróxido de Hidrogênio , Luminol , MicroRNAs/análise
19.
ACS Appl Mater Interfaces ; 14(40): 45096-45109, 2022 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-36171536

RESUMO

The development of superior functional enzyme mimics (nanozymes) is essential for practical applications, including point-of-care diagnostics, biotechnological applications, biofuels, and environmental remediation. Nanozymes with the ability to control their catalytic activity in response to external fuels offer functionally valuable platforms mimicking nonequilibrium systems in nature. Herein, we fabricated a supramolecular coordination bonding-based dynamic vesicle that exhibits multienzymatic activity. The supramolecular nanozyme shows effective laccase-like catalytic activity with a KM value better than the native enzyme and higher stability in harsh conditions. Besides, the nanostructure demonstrates an efficient peroxidase-like activity with NADH peroxidase-like properties. Generation of luminescence from luminol and oxidation of dopamine are efficiently catalyzed by the nanozyme with high sensitivity, which is useful for point-of-care detections. Notably, the active nanozyme exhibits dynamic laccase-mimetic activity in response to pH variation, which has never been explored before. While a neutral/high pH leads to the self-assembly, a low pH disintegrates the assembled nanostructures and consequently turns off the nanozyme activity. Altogether, the self-assembled Cu2+-based vesicular nanostructure presents a pH-fueled dissipative system demonstrating effective temporally controlled multienzymatic activity.


Assuntos
Lacase , Nanoestruturas , Biocombustíveis , Catálise , Dopamina , Luminol , Nanoestruturas/química , Peroxidases
20.
World J Gastroenterol ; 28(32): 4508-4515, 2022 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-36157933

RESUMO

The advantage of endoscopic submucosal dissection (ESD) is that it is less invasive than surgery. ESD is one of the best treatments for older patients as surgery in this age group of patients is difficult. However, it is unclear how much lower the physical stress of ESD is compared with that of surgery. Thus, objective methods are required to assess physical stress in patients who have undergone ESD. The current review of ESD aimed to summarize the recent advancements in the assessment of physical stress during the perioperative period, focusing on changes in energy metabolism and serum opsonic activity (SOA). Based on metabolic changes, resting energy expenditure (REE) was measured using an indirect calorimeter. The stress factor calculated from the REE and the basal energy expenditure computed using the Harris-Benedict equation can be used to assess physical stress. SOA was assessed using the chemiluminescence method, wherein the use of chemiluminescent probes (i.e., lucigenin and luminol) allowed quantification of reactive oxygen species generated by neutrophils. Using an auto luminescence analyzer, the results were evaluated based on the maximum light emission and area under the emission curve. These quantifiable results revealed the minimal invasiveness of ESD.


Assuntos
Ressecção Endoscópica de Mucosa , Ressecção Endoscópica de Mucosa/efeitos adversos , Metabolismo Energético , Humanos , Luminol , Período Perioperatório , Espécies Reativas de Oxigênio , Resultado do Tratamento
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