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Electrochemical approaches, along with miniaturization of electrodes, are increasingly being employed to detect and quantify nucleic acid biomarkers. Miniaturization of the electrodes is achieved through the use of screen-printed electrodes (SPEs), which consist of one to a few dozen sets of electrodes, or by utilizing printed circuit boards. Electrode materials used in SPEs include glassy carbon (Chiang H-C, Wang Y, Zhang Q, Levon K, Biosensors (Basel) 9:2-11, 2019), platinum, carbon, and graphene (Cheng FF, He TT, Miao HT, Shi JJ, Jiang LP, Zhu JJ, ACS Appl Mater Interfaces 7:2979-2985, 2015). There are numerous modifications to the electrode surfaces as well (Cheng FF, He TT, Miao HT, Shi JJ, Jiang LP, Zhu JJ, ACS Appl Mater Interfaces 7:2979-2985, 2015). These approaches offer distinct advantages, primarily due to their demonstrated superior limit of detection without amplification. Using the SPEs and potentiostats, we can detect cells, proteins, DNA, and RNA concentrations in the nanomolar (nM) to attomolar (aM) range. The focus of this chapter is to describe the basic approach adopted for the use of SPEs for nucleic acid measurement.
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Técnicas Biosensibles , Técnicas Electroquímicas , Electrodos , Grafito , Grafito/química , Técnicas Electroquímicas/métodos , Técnicas Electroquímicas/instrumentación , Técnicas Biosensibles/métodos , Técnicas Biosensibles/instrumentación , Ácidos Nucleicos/análisis , Humanos , ADN/análisisRESUMEN
Breast cancer continues to be a significant contributor to global cancer deaths, particularly among women. This highlights the critical role of early detection and treatment in boosting survival rates. While conventional diagnostic methods like mammograms, biopsies, ultrasounds, and MRIs are valuable tools, limitations exist in terms of cost, invasiveness, and the requirement for specialized equipment and trained personnel. Recent shifts towards biosensor technologies offer a promising alternative for monitoring biological processes and providing accurate health diagnostics in a cost-effective, non-invasive manner. These biosensors are particularly advantageous for early detection of primary tumors, metastases, and recurrent diseases, contributing to more effective breast cancer management. The integration of biosensor technology into medical devices has led to the development of low-cost, adaptable, and efficient diagnostic tools. In this framework, electrochemical screening platforms have garnered significant attention due to their selectivity, affordability, and ease of result interpretation. The current review discusses various breast cancer biomarkers and the potential of electrochemical biosensors to revolutionize early cancer detection, making provision for new diagnostic platforms and personalized healthcare solutions.
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Técnicas Biosensibles , Neoplasias de la Mama , Detección Precoz del Cáncer , Técnicas Electroquímicas , Humanos , Técnicas Biosensibles/métodos , Neoplasias de la Mama/diagnóstico , Detección Precoz del Cáncer/métodos , Femenino , Biomarcadores de Tumor/análisisRESUMEN
Ovarian cancer, a prevalent and deadly cancer among women, presents a significant challenge for early detection due to its heterogeneous nature. MicroRNAs, short non-coding regulatory RNA fragments, play a role in various cellular processes. Aberrant expression of these microRNAs has been observed in the carcinogenesis-related processes of many cancer types. Numerous studies highlight the critical role of microRNAs in the initiation and progression of ovarian cancer. Given their clinical importance and predictive value, there has been considerable interest in developing simple, prompt, and sensitive miRNA biosensor strategies. Among these, electrochemical sensors have demonstrated advantageous characteristics such as simplicity, sensitivity, low cost, and scalability. These microRNA-based electrochemical biosensors are valuable tools for early detection and point-of-care applications. This article discusses the potential role of microRNAs in ovarian cancer and recent advances in the development of electrochemical biosensors for miRNA detection in ovarian cancer samples.
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Técnicas Biosensibles , Técnicas Electroquímicas , MicroARNs , Neoplasias Ováricas , Humanos , Neoplasias Ováricas/diagnóstico , Neoplasias Ováricas/genética , Femenino , Técnicas Biosensibles/métodos , MicroARNs/análisis , MicroARNs/genéticaRESUMEN
The contamination of mycotoxins poses a serious threat to global food security, hence the urgent need for simultaneous detection of multiple mycotoxins. Herein, two SERS nanoprobes were synthesized by embedded SERS tags (4-mercaptopyridine, 4MPy; 4-mercaptobenzonitrile, TBN) into the Au and Ag core-shell structure, and each was coupled with the aptamers specific to ochratoxin A (OTA) and zearalenone (ZEN). Meanwhile, a rigid enhanced substrate Indium tin oxide glass/AuNPs/Graphene oxide (ITO/AuNPs/GO) was combined with aptamer functionalized Au@AgNPs via π-π stacking interactions between the aptamer and GO to construct a surface-enhanced Raman spectroscopy (SERS) aptasensor, thereby inducing a SERS enhancement effect for the effective and swift simultaneous detection of both OTA and ZEN. The presence of OTA and ZEN caused signal probes dissociation, resulting in an inverse correlation between Raman signal intensity (1005 cm-1 and 2227 cm-1) and the concentrations of OTA and ZEN, respectively. The SERS aptasensor exhibited wide linear detection ranges of 0.001-20 ng/mL for OTA and 0.1-100 ng/mL for ZEN, with low detection limits (LOD) of 0.94 pg/mL for OTA and 59 pg/mL for ZEN. Furthermore, the developed SERS aptasensor demonstrated feasible applicability in the detection of OTA and ZEN in maize, showcasing its substantial potential for practical implementation.
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Aptámeros de Nucleótidos , Oro , Grafito , Límite de Detección , Nanopartículas del Metal , Ocratoxinas , Plata , Espectrometría Raman , Zearalenona , Ocratoxinas/análisis , Espectrometría Raman/métodos , Oro/química , Zearalenona/análisis , Nanopartículas del Metal/química , Aptámeros de Nucleótidos/química , Plata/química , Grafito/química , Compuestos de Estaño/química , Técnicas Biosensibles/métodos , Contaminación de Alimentos/análisisRESUMEN
The frequent occurrence of food safety incidents has aroused public concern about food safety and key contaminants. Foodborne pathogen contamination, pesticide residues, heavy metal residues, and other food safety problems will significantly impact human health. Therefore, developing efficient and sensitive detection method to ensure food safety early warning is paramount. The aptamer-based sensor (aptasensor) is a novel analytical tool with strong targeting, high sensitivity, low cost, etc. It has been extensively utilized in the pharmaceutical industry, biomedicine, environmental engineering, food safety detection, and in other diverse fields. This work reviewed the latest research progress of aptasensors for food analysis and detection, mainly introducing their application in detecting various key food contaminants. Subsequently, the sensing mechanism and performance of aptasensors are discussed. Finally, the review will examine the challenges and opportunities related to aptasensors for detecting major contaminants in food, and advance implementation of aptasensors in food safety and detection.
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Aptámeros de Nucleótidos , Técnicas Biosensibles , Contaminación de Alimentos , Inocuidad de los Alimentos , Nanoestructuras , Contaminación de Alimentos/análisis , Aptámeros de Nucleótidos/química , Técnicas Biosensibles/instrumentación , Técnicas Biosensibles/métodos , Nanoestructuras/química , Humanos , Análisis de los Alimentos/métodos , Análisis de los Alimentos/instrumentaciónRESUMEN
Phoxim, extensively utilized in agriculture as an organothiophosphate insecticide, has the potential to cause neurotoxicity and pose human health hazards. In this study, an electrochemical enzyme biosensor based on Ti3C2 MXene/MoS2@AuNPs/AChE was constructed for the sensitive detection of phoxim. The two-dimensional multilayer structure of Ti3C2 MXene provides a robust framework for MoS2, leading to an expansion of the specific surface area and effectively preventing re-stacking of Ti3C2 MXene. Additionally, the synergistic effect of self-reduced grown AuNPs with MoS2 further improves the electrical conductivity of the composites, while the robust framework provides a favorable microenvironment for immobilization of enzyme molecules. Ti3C2 MXene/MoS2@AuNPs electrochemical enzyme sensor showed a significant response to phoxim in the range of 1 × 10-13 M to 1 × 10-7 M with a detection limit of 5.29 × 10-15 M. Moreover, the sensor demonstrated excellent repeatability, reproducibility, and stability, thereby showing its promising potential for real sample detection.
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Técnicas Biosensibles , Técnicas Electroquímicas , Frutas , Oro , Nanopartículas del Metal , Nanocompuestos , Compuestos Organotiofosforados , Titanio , Oro/química , Técnicas Electroquímicas/instrumentación , Técnicas Electroquímicas/métodos , Nanocompuestos/química , Frutas/química , Nanopartículas del Metal/química , Técnicas Biosensibles/instrumentación , Compuestos Organotiofosforados/análisis , Titanio/química , Límite de Detección , Contaminación de Alimentos/análisis , Molibdeno/química , Insecticidas/análisis , Insecticidas/química , Residuos de Plaguicidas/análisis , Residuos de Plaguicidas/químicaRESUMEN
Rapid screening for foodborne pathogens is crucial for food safety. A rapid and one-step electrochemical sensor has been developed for the detection of Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and Salmonella typhimurium (S. typhimurium). Through the construction of aptamer/two-dimensional carboxylated Ti3C2Tx (2D C-Ti3C2Tx)/two-dimensional Zn-MOF (2D Zn-MOF) composites, the recognition elements, signal tags, and signal amplifiers are integrated on the electrode surface. Pathogens are selectively captured using the aptamer, which increases the impedance of the electrode surfaceï¼leads to a decrease in the 2D Zn-MOF current. Bacteria can be rapidly quantified using a one-step detection method and the replacement of aptamers. The detection limits for E. coli, S. aureus, and S. typhimurium are 6, 5, and 5 CFU·mL-1, respectively. The sensor demonstrated reliable detection capabilities in real-sample testing. Therefore, the one-step sensor based on the 2D Zn-MOF and 2D C-Ti3C2Tx has significant application value in the detection of foodborne pathogens.
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Técnicas Electroquímicas , Escherichia coli , Salmonella typhimurium , Staphylococcus aureus , Zinc , Staphylococcus aureus/aislamiento & purificación , Salmonella typhimurium/aislamiento & purificación , Zinc/análisis , Escherichia coli/aislamiento & purificación , Técnicas Electroquímicas/instrumentación , Técnicas Biosensibles/instrumentación , Estructuras Metalorgánicas/química , Microbiología de Alimentos , Titanio/química , Límite de Detección , Electrodos , Contaminación de Alimentos/análisisRESUMEN
Quantitative monitoring of the concentrations of epigallocatechin gallate (EGCG) and cysteine (Cys) is of great significance for promoting human health. In this study, iron/aluminum bimetallic MOF material MIL-53 (Fe, Al) was rapidly prepared under room temperature using a co-precipitation method, followed by investigating the peroxidase-like (POD-like) activity of MIL-53(Fe, Al) using 3,3',5,5'-tetramethylbenzidine (TMB) as a chromogenic substrate. The results showed that the Michaelis -Menten constants of TMB and H2O2 as substrates were 0.167 mM and 0.108 mM, respectively. A colorimetric sensing platform for detecting EGCG and Cys was developed and successfully applied for analysis and quantitative detection using a smartphone. The linear detection range for EGCG was 15â¼80 µM (R2=0.994) and for Cys was 7â¼95 µM (R2=0.998). The limits of detection (LOD) were 0.719 µM and 0.363 µM for EGCG and Cys, respectively. This work provides a new and cost-effective approach for the real-time analysis of catechins and amino acids.
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Antioxidantes , Técnicas Biosensibles , Catequina , Colorimetría , Teléfono Inteligente , Colorimetría/métodos , Colorimetría/instrumentación , Técnicas Biosensibles/instrumentación , Técnicas Biosensibles/métodos , Antioxidantes/análisis , Antioxidantes/química , Catequina/análisis , Catequina/análogos & derivados , Catequina/química , Cisteína/análisis , Cisteína/análogos & derivados , Límite de Detección , Análisis de los Alimentos/métodos , Análisis de los Alimentos/instrumentaciónRESUMEN
The development of biosensing electronics for real-time sweat analysis has attracted increasing research interest due to their promising applications for non-invasive health monitoring. However, one of the critical challenges lies in the sebum interference that largely limits the sensing reliability in practical scenarios. Herein, we report a flexible epidermal secretion-purified biosensing patch with a hydrogel filtering membrane that can effectively eliminate the impact of sebum and sebum-soluble substances. The as-prepared sebum filtering membranes feature a dual-layer sebum-resistant structure based on the poly(hydroxyethyl methacrylate) hydrogel functionalized with nano-brush structured poly(sulfobetaine) to eliminate interferences and provide self-cleaning capability. Furthermore, the unidirectional flow microfluidic channels design based on the Tesla valve was incorporated into the biosensing patch to prevent external sebum contamination and allow effective sweat refreshing for reliable sensing. By seamlessly combining these components, the epidermal secretion-purified biosensing patch enables continuous monitoring of sweat uric acid, pH, and sodium ions with significantly improved accuracy of up to 12 %. The proposed strategy for enhanced sweat sensing reliability without sebum interference shows desirable compatibility for different types of biosensors and would inspire the advances of flexible and wearable devices for non-invasive healthcare.
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Técnicas Biosensibles , Hidrogeles , Sebo , Sudor , Técnicas Biosensibles/métodos , Técnicas Biosensibles/instrumentación , Humanos , Sebo/metabolismo , Hidrogeles/química , Sudor/química , Epidermis/metabolismo , Dispositivos Electrónicos Vestibles , Microfluídica/métodos , Ácido Úrico/análisis , Membranas Artificiales , Concentración de Iones de HidrógenoRESUMEN
A variety of shellfish toxin-producing Harmful Algal Blooms (HABs) occur every year in coastal temperate waters worldwide. These toxic HABs may cause lengthy (months) harvesting bans of mussels and other suspension feeding bivalves exposed to their blooms. To safeguard public health and the shellfish industry, European Union regulations request periodic monitoring of potentially toxic microalgae in seawater and phycotoxins in live bivalve molluscs from shellfish production areas. Monitoring of other toxic microalgae, e.g., fish killers, is based solely on cell counts. Morphological identification and quantification of microalgal cells with light microscopy is time-consuming, requires a good expertise, and accurate identification to species level (e.g., Pseudo-nitzschia species) may require electron microscopy. Toxicity varies among morphologically similar species; there are toxic and non-toxic strains of the same species. Molecular techniques using ribosomal DNA sequences offer a possibility to identify and detect precisely the potentially toxic genus/species. In an earlier project (MIDTAL), specific probes against rRNA sequences of all HAB taxa, known at the time of the project, affecting shellfish areas worldwide were designed, and those affecting Europe were tested and calibrated against rRNA extracts of clonal cultures and field samples. Microarray technology was adopted to relate to cell numbers the fluorescence signal from the reaction of all target species probes spotted in the microarray slides with those present in a single sample extract. The EMERTOX project aimed to develop a more automatic "Lab on a chip" (LOC) technology, including a non- (cell) disruptive water concentration system and biosensors for HAB cells detection. Here, calibration curves are presented against toxic microalgae (cultures and field samples) causing endemic and emerging toxicity events in Galicia (NW Spain) and Portugal. Results here relating cell numbers to electrochemical signals will be used in an early warning biosensor for toxic algae.
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Técnicas Biosensibles , Floraciones de Algas Nocivas , Técnicas Biosensibles/métodos , Calibración , Microalgas , Animales , Toxinas Marinas/análisis , Monitoreo del Ambiente/métodosRESUMEN
BACKGROUND: Diabetic retinopathy (DR), a chronic and progressive microvascular complication of diabetes mellitus, substantially threatens vision and is a leading cause of blindness among working-age individuals worldwide. Traditional diagnostic methods, such as ophthalmoscopy and fluorescein angiography are nonquantitative, invasive, and time consuming. Analysis of protein biomarkers in tear fluid offers noninvasive insights into ocular and systemic health, aiding in early DR detection. This study introduces a surface acoustic wave (SAW) microchip that rapidly enhances fluorescence in bead-based immunoassays for the sensitive and noninvasive DR detection from human tear samples. RESULTS: The device facilitated particle mixing for immunoassay formation and particle concentration in the droplet, resulting in an enhanced immunofluorescence signal. This detachable SAW microchip allows the disposal of the cover glass after every use, thereby improving the reusability of the interdigital transducer and minimizing potential cross-contamination. A preliminary clinical test was conducted on a cohort of 10 volunteers, including DR patients and healthy individuals. The results demonstrated strong agreement with ELISA studies, validating the high accuracy rate of the SAW microchip. SIGNIFICANCE: This comprehensive study offers significant insights into the potential application of a novel SAW microchip for the early detection of DR in individuals with diabetes. By utilizing protein biomarkers found in tear fluid, the device facilitates noninvasive, rapid, and sensitive detection, potentially revolutionizing DR diagnostics and improving patient outcomes through timely intervention and management of this vision-threatening condition.
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Retinopatía Diabética , Lágrimas , Humanos , Lágrimas/química , Retinopatía Diabética/diagnóstico , Inmunoensayo/métodos , Sonido , Técnicas Biosensibles/instrumentación , Biomarcadores/análisis , Propiedades de SuperficieRESUMEN
BACKGROUND: Temperature sensing is commonly used in point-of-care (POC) detection technologies, yet the portability and convenience of use are frequently compromised by the complexity of thermosensitive processes and signal transduction. Especially, multi-step target recognition reactions and temperature measurement in the reaction vessel present challenges in terms of stability and integration of detection devices. To further combine photothermal reaction and signal readout in one assay, these two processes enable to be integrated into miniaturized microfluidic chips, thereby facilitating photothermal sensing and achieving a simple visual temperature sensing as POC detection. RESULTS: A copper ion (Cu2+)-catalyzed photothermal sensing system integrated onto a microfluidic distance-based analytical device (µDAD), enabling the visual, portable, and sensitive quantitative detection of multiple targets, including ascorbic acid, glutathione, and alkaline phosphatase (ALP). The polydopamine nanoparticles (PDA NPs) were synthesized by the regulation of free Cu2+ through redox or coordination reactions, facilitating the transduction of distinct photothermal response signals and providing the versatile Cu2+-responsive sensing systems. Promoted by integration with a photothermal µDAD, the system combines PDA's photothermal responsiveness and thermosensitive gas production of ammonium bicarbonate for improved sensitivity of ALP detection, reaching the detection limit of 9.1 mU/L. The system has successfully achieved on-chip detection of ALP with superior anti-interference capability and recoveries ranging from 96.8 % to 104.7 %, alongside relative standard deviations below 8.0 %. SIGNIFICANCE AND NOVELTY: The µDAD design accommodated both the photothermal reaction of PDA NPs and thermosensitive gas production reaction, achieving the rapid sensing of visual distance signals. The µDAD-based Cu2+-catalyzed photothermal sensing system holds substantial potential for applications in biochemical analysis and clinical diagnostics, underscored by the versatile Cu2+ regulation mechanism for a broad spectrum of biomarkers.
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Ácido Ascórbico , Cobre , Indoles , Pruebas en el Punto de Atención , Polímeros , Cobre/química , Indoles/química , Polímeros/química , Catálisis , Ácido Ascórbico/análisis , Ácido Ascórbico/química , Límite de Detección , Fosfatasa Alcalina/metabolismo , Fosfatasa Alcalina/análisis , Fosfatasa Alcalina/química , Temperatura , Humanos , Glutatión/análisis , Glutatión/química , Nanopartículas/química , Procesos Fotoquímicos , Dispositivos Laboratorio en un Chip , Técnicas BiosensiblesRESUMEN
This study explores the fusion of a field-effect transistor (FET), a paper-based analytical cartridge, and the computational power of deep learning (DL) for quantitative biosensing via kinetic analyses. The FET sensors address the low sensitivity challenge observed in paper analytical devices, enabling electrical measurements with kinetic data. The paper-based cartridge eliminates the need for surface chemistry required in FET sensors, ensuring economical operation (cost < $0.15/test). The DL analysis mitigates chronic challenges of FET biosensors such as sample matrix interference, by leveraging kinetic data from target-specific bioreactions. In our proof-of-concept demonstration, our DL-based analyses showcased a coefficient of variation of <6.46% and a decent concentration measurement correlation with an r2 value of >0.976 for cholesterol testing when blindly compared to results obtained from a CLIA-certified clinical laboratory. These integrated technologies have the potential to advance FET-based biosensors, potentially transforming point-of-care diagnostics and at-home testing through enhanced accessibility, ease-of-use, and accuracy.
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Técnicas Biosensibles , Aprendizaje Profundo , Papel , Transistores Electrónicos , Técnicas Biosensibles/instrumentación , Cinética , Colesterol/análisis , HumanosRESUMEN
Structure-switching aptamers have become ubiquitous in several applications, notably in analytical devices such as biosensors, due to their ease of supporting strong signaling. Aside from their ability to bind specifically with their respective target, this class of aptamers also undergoes a conformational rearrangement upon target recognition. While several well-studied and early-developed aptamers (e.g., cocaine, ATP, and thrombin) have been found to have this structure-switching property, the vast majority do not. As a result, it is common to try to engineer aptamers into switches. This proves challenging in part because of the difficulty in obtaining structural and functional information about aptamers. In response, we review various readily available biophysical characterization tools that are capable of assessing structure switching of aptamers. In doing so, we delve into the fundamentals of these different techniques and detail how they have been utilized in characterizing structure-switching aptamers. While each of these biophysical techniques alone has utility, their real power to demonstrate the occurrence of structural change with ligand binding is when multiple techniques are used. We hope that through a deeper understanding of these techniques, researchers will be better able to acquire biophysical information about their aptamer-ligand systems and accelerate the translation of aptamers into biosensors.
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Aptámeros de Nucleótidos , Conformación de Ácido Nucleico , Aptámeros de Nucleótidos/química , Aptámeros de Nucleótidos/metabolismo , Soluciones , Humanos , Fenómenos Biofísicos , Técnicas BiosensiblesRESUMEN
Detecting dopamine (DA) in biological samples is vital to understand its crucial role in numerous physiological processes, such as motion, cognition, and reward stimulus. In this work, p-type graphene on sapphire, synthesized via chemical vapor deposition, serves as substrate for the preparation of p-type Cu2-xS films through solid-phase sulfurization. The optimized Cu2-xS/graphene heterostructure, prepared at 250 °C using a 15-nm copper film sulfurized for 2 h, exhibits superior electron transfer performance, ideal for electrochemical sensing. It is confirmed that the spontaneous charge transfer from graphene to Cu2-xS, higher Cu(II)/Cu(I) ratio (~ 0.8), and the presence of well-defined nanocrystalline structures with an average size of ~ 35 nm in Cu2-xS significantly contribute to the improved electron transfer of the heterostructure. The electrochemical sensor based on Cu2-xS/graphene heterostructure demonstrates remarkable sensitivity towards DA, with a detection limit as low as 100 fM and a dynamic range greater than 109 from 100 fM to 100 µM. Additionally, it exhibits excellent selectivity even in the presence of uric acid and ascorbic acid 100 times higher, alongside notable storage and measurement stability and repeatability. Impressively, the sensor also proves capable of detecting DA concentrations as low as 100 pM in rat serum, showcasing its potential for clinically relevant analytes and promising applications in sensitive, selective, reliable, and efficient point-of-care diagnostics.
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Cobre , Dopamina , Técnicas Electroquímicas , Grafito , Límite de Detección , Dopamina/sangre , Dopamina/análisis , Cobre/química , Grafito/química , Técnicas Electroquímicas/métodos , Técnicas Electroquímicas/instrumentación , Animales , Ratas , Técnicas Biosensibles/métodos , ElectrodosRESUMEN
CONTEXT: Airborne pathogens, defined as microscopic organisms, pose significant health risks and can potentially cause a variety of diseases. Given their ability to spread through diverse transmission routes from infected hosts, there is a critical need for accurate monitoring of these pathogens. This study aims to develop a sensor by investigating the vibrational responses of cantilever and bridged boundary-conditioned single-layer graphene (SLG) sheets with microorganisms, specifically SARS-CoV-2, attached at various positions on the sheet. The dynamic analysis of SLG with different boundary conditions and lengths was conducted using the atomistic finite element method (AFEM). Simulations were performed to evaluate SLG's performance as a sensor for biological entities. Altering the sheet's length and the mass of the attached biological object revealed observable frequency differences. This sensor design shows promise for enhancing the detection capabilities of graphene-based technologies for viruses. METHODS: Finite element method (FEM) analysis is employed to model the sensor's performance and optimize its design parameters. The simulation results highlight the sensor's potential for achieving high sensitivity and rapid detection of SARS-CoV-2. Bridged and cantilever boundary conditions are applied at the ends of the SLG structure by using ANSYS software. Simulations have been conducted to observe how SLG behaves when used as sensors. In armchair graphene, under both boundary conditions, an SLG (5, 5) structure with a length of 50 nm displayed the highest frequency when a SARS-CoV-2 molecule with a mass of 2.6594 × 10-18 g was attached. Conversely, the chiral SLG (17, 1) structure exhibited its lowest frequency at a length of 10 nm. This insight is crucial for grasping detection limits and how factors such as size and boundary conditions influence sensor efficacy. These biosensors hold immense promise in biological sciences and medical applications, revolutionizing patient care by enabling early detection and accurate pathogen identification in clinical settings.
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Técnicas Biosensibles , COVID-19 , Análisis de Elementos Finitos , Grafito , SARS-CoV-2 , Grafito/química , SARS-CoV-2/aislamiento & purificación , Técnicas Biosensibles/métodos , COVID-19/virología , Humanos , Simulación por ComputadorRESUMEN
The fast spread and severe consequences of novel coronavirus disease 2019 (COVID-19) have once again underscored the critical necessity of early detection of viral infections. Several serology-based techniques, including as point-of-care assays and high-throughput enzyme immunoassays that support the diagnosis of COVID-19 are utilized in the detection and identification of coronaviruses. A rapid, precise, simple, affordable, and adaptable diagnostic tool is required for controlling COVID-19 as well as for outbreak management, since the calculation and monitoring of viral loads are crucial for predicting the infection stage and recovery time. Nowadays, the most popular method for diagnosing COVID-19 is reverse transcription polymerase chain reaction (RT-PCR) testing, and chest computed tomography (CT) scans are also used to determine the disease's phases. This is all because of the fact that RT-PCR method caries with itself a number of downsides comprising of being immovable, expensive, and laborious. RT-PCR has not well proven to be capable of detection on the very early infection stages. Nanomaterial-based diagnostics, together with traditional clinical procedures, have a lot of promise against COVID-19. It is worthy of attention that nanotechnology has the mainstay capacity for purposes of developing even more modern stratagems fighting COVID-19 by means of focusing on state-of-the-art diagnostics. What we have centered on in this review, is bringing out even more efficient detection techniques whereby nanobiosensors are employed so that we might obstruct any further development and spreading of SARS-CoV-2.
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COVID-19 , SARS-CoV-2 , Humanos , COVID-19/diagnóstico , Técnicas Biosensibles/métodos , Prueba de COVID-19/métodosRESUMEN
Binding-activated optical sensors are powerful tools for imaging, diagnostics, and biomolecular sensing. However, biosensor discovery is slow and requires tedious steps in rational design, screening, and characterization. Here we report on a platform that streamlines biosensor discovery and unlocks directed nanosensor evolution through genetically encodable fluorogenic amino acids (FgAAs). Building on the classical knowledge-based semisynthetic approach, we engineer ~15 kDa nanosensors that recognize specific proteins, peptides, and small molecules with up to 100-fold fluorescence increases and subsecond kinetics, allowing real-time and wash-free target sensing and live-cell bioimaging. An optimized genetic code expansion chemistry with FgAAs further enables rapid (~3 h) ribosomal nanosensor discovery via the cell-free translation of hundreds of candidates in parallel and directed nanosensor evolution with improved variant-specific sensitivities (up to ~250-fold) for SARS-CoV-2 antigens. Altogether, this platform could accelerate the discovery of fluorogenic nanosensors and pave the way to modify proteins with other non-standard functionalities for diverse applications.
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Aminoácidos , Técnicas Biosensibles , Colorantes Fluorescentes , SARS-CoV-2 , Técnicas Biosensibles/métodos , Colorantes Fluorescentes/química , Humanos , SARS-CoV-2/genética , COVID-19/virología , Nanotecnología/métodos , Péptidos/metabolismo , Péptidos/química , Péptidos/genéticaRESUMEN
A dual-emission fluorescent biosensing method was developed for simultaneous determination of CaMV35S and NOS in genetically modified (GM) plants. Two designed hairpin DNA (H1, H2) sequences were used as templates to synthesize H1-AgNCs (λex = 570 nm, λem = 625 nm) and H2-AgNCs (λex = 470 nm, λem = 555 nm). By using H1-AgNCs and H2-AgNCs as dual-signal tags, combined with signal amplification strategy of magnetic separation to reduce background signal and an enzyme-free catalytic hairpin assembly (CHA) signal amplification strategy, a novel multi-target fluorescent biosensor was fabricated to detect multiple targets based on FRET between signal tags (donors) and magnetic Fe3O4 modified graphene oxide (Fe3O4@GO, acceptors). In the presence of the target NOS and CaMV35S, the hairpin structures of H1 and H2 can be opened respectively, and the exposed sequences will hybridize with the G-rich hairpin sequences HP1 and HP2 respectively, displacing the target sequences to participate in the next round of CHA cycle. Meanwhile, H1-HP1 and H2-HP2 double-stranded DNA sequences (dsDNA) were formed, resulting in the desorption of dsDNA from the surface of Fe3O4@GO due to weak π-π interaction between dsDNA and Fe3O4@GO and leading to the fluorescence recovery of AgNCs. Under optimal conditions, the linear ranges of this fluorescence sensor were 5 ~ 300 nmol L-1 for NOS and 5 ~ 200 nmol L-1 CaMV35S, and the LODs were 0.14 nmol L-1 and 0.18 nmol L-1, respectively. In addition, the fluorescence sensor has good selectivity for the detection of NOS and CaMV35S in GM soybean samples, showing the potential applications in GM screening.
Asunto(s)
Técnicas Biosensibles , Límite de Detección , Nanopartículas del Metal , Plata , Plata/química , Técnicas Biosensibles/métodos , Nanopartículas del Metal/química , Transferencia Resonante de Energía de Fluorescencia/métodos , Grafito/química , Secuencias Invertidas Repetidas , Plantas Modificadas Genéticamente/genética , Catálisis , Colorantes Fluorescentes/química , Caulimovirus/genética , Técnicas de Amplificación de Ácido Nucleico/métodos , Proteínas Virales/química , Proteínas Virales/genética , Aminoácido OxidorreductasasRESUMEN
A cortisol biosensor was developed based on double-conducting polymer nanowires, which exhibits excellent conductivity, resistance to biological contamination, and outstanding sensing performance. The biosensor employs dual-mode electrochemical techniques, namely, differential pulse voltammetry (DPV) and chronoamperometry (CA), for the sensitive and low fouling detection of the glucocorticoid hormone cortisol. Experimental results demonstrated that the linear detection range of the biosensor in DPV mode was 1.0 × 10-14-1.0 × 10-8 M, with a detection limit of 0.131 × 10-14 M. In CA mode, the biosensor exhibited a detection range of 1.0 × 10-13-1.0 × 10-7 M and a detection limit of 0.313 × 10-13 M. The biosensor was successfully utilized for the rapid detection of cortisol in human saliva. The combination of a high-specificity cortisol aptamer and functionalized double-conducting polymer nanowires ensured the exceptional specificity and sensitivity of the biosensor in detecting real biological samples.