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1.
Spectrochim Acta A Mol Biomol Spectrosc ; 324: 124946, 2025 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-39208543

RESUMEN

A highly efficient system that incorporates the instantaneous visualization of the cyanide ion in water was synthesized by keeping the fluorophore system (electron donor) as a julolidine-coumarin conjugate and changing the electron acceptor unit. The probes exhibit a notable color change in normal and UV light. The probe interaction modalities are based on the ICT process. With a detection limit in the nM range, it may preferentially react with cyanide, which is less than the tolerable level of 1.9 µM. According to 1H NMR data, the probes detect cyanide ions by nucleophilic addition reaction mechanism. Furthermore, current probe successfully determines real resources, including cyanide containing cassava powder, sprouted potatoes and various water samples. Besides the test strips, an electronic Arduino device was also employed to detect the cyanide ion. As such, the developed probes exhibit outstanding practical application with respect to the cyanide ion.

2.
Food Chem ; 462: 140988, 2025 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-39216370

RESUMEN

The 3,3',5,5'-tetramethylbenzidine-H2O2 (TMB-H2O2) platform has gained widespread use for rapid detection of various analytes in foods. However, the existing TMB-H2O2 platforms suffer from limited accuracy, as their signal output is confined to the visible region, which is prone to interference from various food colorants in real samples. To address this challenge, a novel Au@Os-mediated TMB-H2O2 platform is developed for both rapid and accurate detection of analytes in foods. The prepared Au@Os NPs exhibit remarkable peroxidase-like activity, making the platform display dual absorption peaks in visible and near-infrared (NIR) regions, respectively. This Au@Os-mediated TMB-H2O2 platform exhibited three linear ranges across different concentrations of ziram from 1-100, 150-600, and 800-2000 nM with limit of detection (LOD) 7.9 nM and limit of quantification (LOQ) 24.15 nM respectively. Further, the Au@Os-mediated TMB-H2O2 platform was also used for rapid and accurate detection of ziram in real food samples like apple, tomato, and black tea.


Asunto(s)
Contaminación de Alimentos , Oro , Peróxido de Hidrógeno , Límite de Detección , Peróxido de Hidrógeno/química , Peróxido de Hidrógeno/análisis , Oro/química , Contaminación de Alimentos/análisis , Bencidinas/química , Malus/química , Solanum lycopersicum/química , Té/química , Nanopartículas del Metal/química , Colorantes de Alimentos/análisis
3.
Food Chem ; 462: 141026, 2025 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-39216373

RESUMEN

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 15∼80 µM (R2=0.994) and for Cys was 7∼95 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.


Asunto(s)
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/instrumentación
4.
Spectrochim Acta A Mol Biomol Spectrosc ; 324: 124948, 2025 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-39146630

RESUMEN

Herein, a nanocomposite of Cu,Ce-containing phosphotungstates (Cu,Ce-PTs) with outstanding laccase-like activity was fabricated via a one-pot microwave-assisted hydrothermal method. Notably, it was discovered that both Fe3+ and Cr6+ could significantly enhance the electron transfer rates of Ce3+ and Ce4+, along with generous Cu2+ with high catalytic activity, thereby promoting the laccase-like activity of Cu,Ce-PTs. The proposed system can be used for the detection of Fe3+ and Cr6+ in a range of 0.667-333.33 µg/mL and 0.033-33.33 µg/mL with a low detection limit of 0.135 µg/mL and 0.0288 µg/mL, respectively. The proposed assay exhibits excellent reusability and selectivity and can be used in traditional Chinese medicine samples analysis.


Asunto(s)
Cerio , Cromo , Colorimetría , Cobre , Hierro , Lacasa , Cobre/análisis , Cobre/química , Cromo/análisis , Colorimetría/métodos , Lacasa/metabolismo , Lacasa/química , Hierro/análisis , Hierro/química , Cerio/química , Límite de Detección , Ácido Fosfotúngstico/química , Nanocompuestos/química , Catálisis
5.
Spectrochim Acta A Mol Biomol Spectrosc ; 324: 124967, 2025 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-39153350

RESUMEN

Hexavalent chromium (CrVI) poses a serious risk to both human and environment health. Hence, a simple, robust, and efficient analytical method must be developed to monitor the presence of Cr(VI) in the environment. The current investigation concentrated on the colorimetric detection of Cr(VI) using TMB as indicator in the presence of H2O2. The study found that Cr(VI) reacts with H2O2 to generate hydroxyl radicals which oxidize TMB in a concentration dependent manner. Under optimized conditions, the method obtained a good linearity range (0.025-0.5 mg/L, r2 = 0.9944) with LOD and LOQ of 0.009 mg/L and 0.029 mg/L, respectively. The technique was further improved by the addition of EDTA in the sample preparation protocol to reduce the false positive result by the presence of ions like Cu2+, Fe3+, etc. The study recorded improved Cr(VI) recoveries (81.73-111.40 %) at different fortification levels (0.1-0.5 mg/L). Under optimized conditions, the EDTA added method obtained a good linear response (r2 = 0.9952) with a detection limit of 0.023 mg/L which is less than the prescribed limits by WHO (0.05 mg/L) and US EPA (0.1 mg/L) for drinking water. The developed analytical method is very simple without use of any nanomaterial and the results with natural water samples show that it has the potential for real-time detection of Cr(VI) in the environment.

6.
Spectrochim Acta A Mol Biomol Spectrosc ; 324: 124982, 2025 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-39173318

RESUMEN

Imine based positional isomers (8E)-N-(4-((E)-(perfluorophenylimino)methyl)benzylidene)-2,3,4,5,6-pentafluorobenzenamine, L and (10E)-N-(3-(E-Perfluorophenylimino)methyl)benzylidene)-2,3,4,5,6-pentafluorobenzenamine, L1 have been designed, and synthesized by functionalizing two electron deficient aromatic moieties at the para-para'/ortho-ortho' positions in the phenyl core of the L and L1 respectively. The responses of L and L1 towards various anionic species are examined. The positional isomers L and L1 differs not only by showing distinguishable color change upon addition of anions but also differentiates themselves by the way of self-assembling together upon binding with cyanide anion. The naked-eye colorimetric experiments, UV-Vis, Nuclear Magnetic Resonance, and Infra-Red spectroscopic analyses reveal that the isomer L binds fluoride anion through 2:1 stoichiometry ratio. Unlike fluoride complex, the isomer L form aggregates while binding with cyanide ion. On the other hand, isomer L1 does not show any instant color change upon additions of any anion. Interestingly, after thirty minutes, only the color of the cyanide complex is turned into dark brown. While analyzing the spectroscopic results of cyanide complex of L1, it is found that the cyanide complex begins to decompose and finally it is completely decomposed within 30 min. This unprecedented phenomenon about the colorimetric sensing of cyanide and destruction of cyanide complex with respect to time has not been reported in the literature yet. To the best of our knowledge this is the first example of study of sensing controlling the selectivity, mode of binding, self-aggregating and degradation properties of anionic complexes under the influence of positional isomeric effects. This present investigation provides simple and effective strategy to construct the sensor molecules with tunable binding properties in terms of easy to prepare as well as easy to use as a colorimetric sensor. _____________________________________________________________________________________________________.

7.
Cureus ; 16(8): e67322, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39301399

RESUMEN

Carbapenem-resistant Enterobacterales, particularly those that produce carbapenemases, pose a significant public health concern due to very limited treatment options. The timely identification of carbapenemase-producing Enterobacterales (CPE) is essential for putting in place efficient infection control measures and selecting appropriate antimicrobial therapies, thereby improving the clinical outcome of the patient. The purpose of this systematic review is to compare the diagnostic accuracy and practicality between two phenotypic tests, namely the modified carbapenem inactivation method (mCIM) and carbapenemase Nordmann-Poirel (Carba NP) test, in detecting carbapenemase production by Enterobacterales and thereby aiding the clinician in making a decision to choose an appropriate test for their phenotypic detection. This systematic review involved combining sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, diagnostic odds ratio with 95% confidence interval (CIs), Forest plot for sensitivity and specificity, and plotting suitable summary receiver operating characteristic curve with the area under the curve. Of the 20 studies included in this review, the overall effect sizes of Carba NP and mCIM with 95% CIs were as follows: sensitivity, 91% (86-96%) and 97% (95-99%); specificity, 93% (88-97%) and 97% (93-100%); PPV, 97% and 98%; NPV, 79% and 90%; accuracy, 93% and 97%; diagnostic odds ratio, 1487.8879 and 8527.5541; and AUC, 0.85 and 1, respectively. In conclusion, the mCIM method showed superior sensitivity (97%), specificity (97%), and accuracy compared to the Carba NP test in detecting carbapenemase production, even though both these methods had a few technical limitations. The Carba NP test is rapid, affordable, and dependable, whereas mCIM is more accurate and cost-effective but time-consuming. We propose that both tests can be reliably used for screening of carbapenemase production in Enterobacterales, as endorsed by the Clinical and Laboratory Standards Institute even in resource-limited clinical laboratories, in the order of prioritizing the mCIM method first and then followed by the Carba NP test when situation demands expedited results.

8.
Talanta ; 281: 126820, 2024 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-39260247

RESUMEN

With the rapid expansion of the health food industry, the scope of safety supervision has also increased. However, traditional instrument detection methods cannot meet the requirements for the rapid on-site detection. Hence, the development of a rapid, precise, and simple method for the analysis of illegal additives in health foods is of great importance. In this work, by using FeCo-MOFs as mimetic peroxidase to mediate Au nanorods (Au NRs) etching, a dual-mode immunosensor based on multi-colorimetric and photothermal signals was fabricated to detect furosemide (FUR). In multi-colorimetric channel, the localized surface plasmon resonance (LSPR) peaks of Au NRs shifted blue, resulting in multi-color changes from red to gray to blue and finally to purple. In photothermal channel, the photothermal effect of Au NRs decreased, resulting in temperature changes. In the range of 1.0 × 10-5-1.0 × 10-2 µg/mL, both LSPR peak blue shift and temperature changes were linearly correlated with the logarithm of FUR concentration, with the detection limits were 4.9 × 10-6 and 8.5 × 10-6 µg/mL, respectively. Furthermore, its concentration can be accurately and intuitively assessed through the observation of vivid colorimetric changes. This advancement offers a highly promising approach for the on-site detection of FUR, facilitating timely and efficient monitoring, thereby significantly enhancing regulatory compliance and ensuring consumer safety.

9.
Anal Chim Acta ; 1326: 343150, 2024 Oct 16.
Artículo en Inglés | MEDLINE | ID: mdl-39260918

RESUMEN

BACKGROUND: To minimize the impact of pesticide residues in food on human health, it is necessary to enhance their detection. Recently, many nanozyme-based colorimetric methods for pesticides detection have been developed, however, they often required the assistance of natural enzymes, which made the process and result of methods susceptible to the stability and activity of natural enzymes. To overcome these drawbacks, methods for direct detection of pesticides using nanozymes have been developed, and there are few studies in this field currently. Thus, it is of great research and practical significance to develop more nanozymes-based colorimetric methods for direct detection of pesticides. RESULTS: Dual colorimetric platforms based on Os-Rh nanozyme with excellent peroxidase-like activity were constructed for directly detection of glyphosate in this work. Results showed that glyphosate was able to sensitively and selectively inhibit the peroxidase-like activity of Os-Rh nanozyme through hindering the decomposition of H2O2 by Os-Rh nanozyme to produce HO∙. Based on this, the dual colorimetric platforms achieved highly sensitive detection for glyphosate over a wide linear concentration range (50-1000 µg L-1 in solution platform and 200-1000 µg L-1 in paper platform), with the detection limits of 28.37 µg L-1 in solution platform and 400 µg L-1 (naked-eye detection limit)/123.25 µg L-1 (gray scale detection limit) in paper platform, respectively. Moreover, the dual colorimetric platforms possessed satisfactory reliability and accuracy for practical applications, and has been successfully applied to the detection of real samples with the spiked recoveries of 92.78-102.75 % and RSD of 1.17-3.88 %. SIGNIFICANCE: The dual colorimetric platforms for glyphosate direct detection based on Os-Rh nanozyme developed in this work not only owned considerable practical application potential, but also could provide more inspirations and ideas for the rational design and development of colorimetric sensing methods for the rapid detection of pesticides based on nanozymes.


Asunto(s)
Colorimetría , Glicina , Glifosato , Colorimetría/métodos , Glicina/análogos & derivados , Glicina/análisis , Glicina/química , Peroxidasa/metabolismo , Peroxidasa/química , Límite de Detección , Peróxido de Hidrógeno/química
10.
Adv Sci (Weinh) ; : e2406196, 2024 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-39297315

RESUMEN

The colloidal gold nanoparticle (AuNP)-based colorimetric lateral flow assay (LFA) is one of the most promising analytical tools for point-of-care disease diagnosis. However, the low sensitivity and insufficient accuracy still limit its clinical application. In this work, a machine learning (ML)-optimized colorimetric LFA with ultrasound enrichment is developed to achieve the sensitive and accurate detection of tau proteins for early screening of Alzheimer's disease (AD). The LFA device is integrated with a portable ultrasonic actuator to rapidly enrich microparticles using ultrasound, which is essential for sample pre-enrichment to improve the sensitivity, followed by ML algorithms to classify and predict the enhanced colorimetric signals. The results of the undiluted serum sample testing show that the protocol enables efficient classification and accurate quantification of the AD biomarker tau protein concentration with an average classification accuracy of 98.11% and an average prediction accuracy of 99.99%, achieving a limit of detection (LOD) as sensitive as 10.30 pg mL-1. Further point-of-care testing (POCT) of human plasma samples demonstrates the potential use of LFA in clinical trials. Such a reliable lateral flow immunosensor with high precision and superb sensing performance is expected to put LFA in perspective as an AD clinical diagnostic platform.

11.
Anal Chim Acta ; 1325: 343119, 2024 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-39244305

RESUMEN

BACKGROUND: On-site monitoring of vanillylmandelic acid (VMA), homovanillic acid (HVA), and dopamine (DA) as key diagnostic biomarkers for a wide range of neurological disorders holds utmost significance in clinical settings. Numerous colorimetric sensors with mechanistic approaches based on aggregation or silver metallization have been introduced for this purpose. However, these mechanisms have drawbacks, such as sensitivity to environmental factors and probe toxicity. Therefore, there is a great demand for a robust yet non-toxic colorimetric sensor that employs a novel route to monitor these biomarkers effectively. RESULTS: Here, we present a single-component multi-colorimetric probe based on the controllable etching suppression of gold nanorods (AuNRs) upon exposure to the mild etchant N-bromosuccinimide (NBS), designed to accurately detect and discriminate VMA, HVA, DA, and their corresponding mixtures, i.e. , VMA: HVA, VMA:DA, HVA:DA, and VMA:HVA:DA. To enhance the sensitivity and automation capabilities of the designed multi-colorimetric sensor, two machine learning techniques were employed: linear discriminant analysis (LDA) for the qualitative classification and partial least-squares regression (PLSR) for the quantitative analysis of pure biomarkers and their mixtures. The outcomes revealed a high correlation between measured and predicted values, covering a linear range of 0.8-25, 1.2-25, and 2.7-100 µmol L-1, with remarkably low detection limits of 0.260, 0.397, and 0.913 µmol L-1 for VMA, HVA, and DA, respectively. Lastly, the performance of the probe was validated by successfully detecting the neuroblastoma biomarker VMA:HVA in human urine. SIGNIFICANCE: Our designed multi-colorimetric probe introduces a rapid, cost-effective, user-friendly, non-toxic, and non-invasive approach to detecting and discriminating not only the pure biomarkers but also their corresponding binary and ternary mixtures. The distinctive response profiles produced by the probe in the presence of different mixture ratios can indicate various disease states in patients, which is highly crucial in clinical diagnostics.


Asunto(s)
Biomarcadores de Tumor , Oro , Nanotubos , Neuroblastoma , Oro/química , Nanotubos/química , Humanos , Biomarcadores de Tumor/análisis , Biomarcadores de Tumor/orina , Colorimetría , Ácido Homovanílico/orina , Dopamina/análisis , Dopamina/orina , Ácido Vanilmandélico/orina
12.
Int J Biol Macromol ; 279(Pt 2): 135236, 2024 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-39218171

RESUMEN

An intelligent pH response indicator film is an easy-to-use device for the real-time monitoring of meat freshness during transport and storage. Therefore, a novel pH-sensitive anthocyanin indicator film composed of polyvinyl alcohol-blueberry anthocyanin (BA)-2-hydroxypropyltrimethyl ammonium chloride chitosan (HACC) called PAH-2.0 with 1.2 mg/mL HACC to monitor meat freshness using HACC as the colorimetric enhancer has been developed. BA and HACC were mixed and immobilized in the polyvinyl alcohol matrix by hydrogen bonds, as confirmed via Fourier-transform infrared spectroscopy and X-ray diffraction. The inclusion of HACC improved the color stability and antioxidant and antibacterial properties of the PAH-2.0 film. When applied to pork for freshness monitoring at 4 °C, three freshness stages, including fresh, sub-fresh, and spoiled, could be clearly distinguished based on the color variations of the PAH-2.0 film. The distinct hierarchical color change from purple to blue-violet and finally to grayish-blue was highly correlated with the indicators of pork freshness: pH values, total volatile basic nitrogen, and total viable count. This study provides a simple and promising approach for fabricating meat freshness indicator films with high color recognition accuracy, thereby offering new possibilities for visual meat freshness monitoring.

13.
Chemphyschem ; : e202400803, 2024 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-39245645

RESUMEN

Three new chromogenic receptors have been synthesized with the primary objective of facilitating the selective recognition of PO43¯and CO32¯ ions in an organo-aqueous medium. R1 and R2 exhibit an extraordinary detection limit aligning with both EPA and WHO guidelines. R1 shows LOD of 0.135 ppm for PO43¯ and 0.175 ppm for CO32¯, while R2 sets forth a LOD of 0.427 ppm for PO43¯ and 0.729 ppm for CO32¯. The binding mechanism involves intramolecular charge transfer (ICT) band are substantiated by comprehensive studies that include UV-Vis titration, 1H-NMR titration, DFT studies and electrochemical studies. Chemosensors were employed in the formulation of logic gate, the fabrication of a paper strip test kit and its application in RGB color sensor device.

14.
Mikrochim Acta ; 191(10): 582, 2024 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-39245663

RESUMEN

A novel colorimetric approach specifically designed to effectively identify the presence of 3-aminophenol (3-AP) in environmental water is introduced. Briefly, a nitrogen-doped carbon-supported cobalt nanozyme (Co@CN-1) was synthesized and utilized to improve the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of peroxymonosulfate (PMS). Comparative catalytic reactions confirmed that the performance of PMS as an activator exceeds that of hydrogen peroxide catalytically by a factor of 3.5. The catalytic reaction parameters underwent optimization, further resulting in the derivation of a linear detection equation for 3-AP, expressed as inhibition rate (IR%) = 3.35[3-AP]-4.36 (0-20 µM, R2 = 0.994) and IR% = 1.43[3-AP] + 31.87 (20-36 µM, R2 = 0.992), with the limit of detection (LOD) of 2.84 µM. The linear relationship between 3-AP concentration and the conversion of color to grayscale value (GSV) was established by smartphones, expressed as GSV = 1.28[3-AP] + 147.10 (R2 = 0.972). Density functional theory calculations revealed that Co acts as the preferred active site for donating electrons in PMS activation. This work provides a rapid and accurate approach for monitoring 3-AP concentration, enabling real-time analysis and potentially contributing to environmental and ecological studies.

15.
Food Chem ; 463(Pt 2): 141207, 2024 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-39276544

RESUMEN

A facile and efficient detection method is required to address the potential health risks of ketoprofen (KP) in animal-derived foods. Herein, we integrated molecularly imprinted polymers (MIPs) with Cu-doped Fe3O4 nanozymes (Fe3O4-Cu) to develop a selective colorimetric sensor for KP detection. Chitosan and glutaraldehyde were used as functional monomers and cross-linkers to fabricate proposed the MIPs@Fe3O4-Cu. On KP addition, it was specifically captured by the imprinted cavities, thereby blocking the channels between chromogenic substrates and Fe3O4-Cu. Based on this rationale, a selective colorimetric sensor utilizing MIPs@Fe3O4-Cu was established, exhibiting a linear range of 0.25-100 µM and a detection limit of 0.073 µM. The developed method was validated through its application in milk samples, yielding satisfactory recoveries with low relative standard deviations. This efficient and selective colorimetric sensor holds immense significance for KP detection in complex samples.

16.
Talanta ; 281: 126847, 2024 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-39276576

RESUMEN

Heparin, a widely studied glycosaminoglycan, plays crucial roles in the regulation of various physiological and pathological processes. Therefore, it's important to develop highly selective and sensitive methods for convenient monitoring of heparin levels in biological systems. We report the design and synthesis of Fe3O4@PDA@MnO2 nanoparticles (FPM-NPs), which exhibit dual enzymatic activities, enabling quantitative detection of heparin. The FPM-NPs feature a unique tri-layer spherical shell structure, possessing both peroxidase-like and oxidase-like activities, and catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) in the presence or absence of H2O2. Remarkably, upon co-incubated with heparin, the oxidase activity of FPM-NPs decreases, while the peroxidase activity increases. By leveraging these dual enzymatic properties of FPM-NPs, a highly sensitive and specific colorimetric detection of heparin is achieved, with a detection limit reaching 6.51 nM and a good linear response to quantify heparin ranging 10-800 nM. Additionally, the developed FPM-NPs are successfully applied to measure heparin in fetal bovine serum samples. We also extend this detection method to a paper-based chip, enabling portable detection of heparin through grayscale analysis of mobile phone photographs. The multi-nanozyme-based heparin detection approach provides a new perspective for future research on expanding the application of nanocomposite materials in biomedical detection and analysis.

17.
Food Res Int ; 195: 114960, 2024 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-39277264

RESUMEN

Lu'an Gua Pian (LAGP) tea is one of the most famous green teas in China. The quality of green tea is related to its picking periods, especially the green tea before Qingming Festival (usually April 6th) is highly praised as precious in the market. In this work, a simple and cheap indicator displacement colorimetric sensor array combined with smartphone was developed to rapidly identify LAGP picked during different picking periods. First, the chemical component contents of LAGP picked before and after Qingming Festival were analyzed. Second, a well-designed colorimetric sensor array was proposed based on the tea component contents differences. Finally, machine learning was used to process the array data taken by a smartphone. By comparison, the accuracy of the best model for the prediction set was 97%. Meanwhile, the multi-channel advantages of the sensing array were demonstrated by an ablation experiment. In addition, the method achieved an AGREE analysis score of 0.88, indicating that it was environmental-friendly.


Asunto(s)
Colorimetría , Aprendizaje Automático , , Té/química , Colorimetría/métodos , China , Teléfono Inteligente , Camellia sinensis/química
18.
Int J Biol Macromol ; : 135651, 2024 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-39278429

RESUMEN

Breast cancer, the most common cancer among women worldwide, lacks specific tumor markers for accurate diagnosis. Recent advances have highlighted tumor-derived exosomes as a promising non-invasive biomarker for cancer detection. Continuous monitoring of surface protein markers on exosomes in the blood could offer valuable insights for breast cancer diagnosis. However, integrating the isolation and detection of exosomes from whole blood is bulky, time-consuming, and requires professional operations. To address this difficulty, we developed a method of integrated centrifugal disk chip (CD chip) exosome enrichment directly from whole blood followed by a colorimetric visualization strategy for multiplex analysis. The disc consists of multi-chambers and multi-microchannels with immediate smartphone-enabled processing of colorimetric results. The combination of CEA + CA125 + EGFR on-chip detection could significantly differentiate the different stages of cancer in tumor-bearing mice and successfully distinguish between breast cancer patients and healthy individuals. Crucially, small volumes (100 µL) of blood samples were adequate. In addition, the chip was simple and fast, with results within 10 min, which provides immediate exosomal information through consecutive blood sampling, which could potentially result in a more timely and well-informed clinical breast cancer diagnosis.

19.
J Infect Dev Ctries ; 18(8): 1196-1203, 2024 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-39288391

RESUMEN

INTRODUCTION: COVID-19, an emerging infectious disease caused by SARS-CoV-2, continues to be a global public health threat. The development of a colorimetric reverse transcription loop-mediated isothermal amplification (RT-LAMP) can extend the availability of simple, reliable molecular tests for the rapid detection of COVID-19. METHODOLOGY: The RT-LAMP assay was developed using a new primer set targeting a portion of SARS-CoV-2 orf8. The method was validated at 63 ºC for 60 minutes with naked-eye visualization of the color change. The clinical performance was compared to a real-time reverse transcription-polymerase chain reaction (rtRT-PCR) using 273 RNA samples extracted from nasopharyngeal swab specimens. RESULTS: The developed RT-LAMP was specific to SARS-CoV-2 with a limit of detection at 15 RNA copies per reaction. The assay demonstrated diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of 90.48% (95% CI: 86.36-93.68%), 87.00% (95% CI: 81.53-91.33%), 100% (95% CI: 95.07-100%), 100% (95% CI: not available), and 73.74% (95% CI: 66.22-80.07%), respectively, compared to the rtRT-PCR. The greatest sensitivity of 98.03% (95% CI: 94.34-99.59%) was demonstrated in samples with the cycle threshold (Ct) values < 30 cycles. CONCLUSIONS: The RT-LAMP method in this study showed good performance. The assay can increase the scope of laboratory testing for rapidly detecting SARS-CoV-2 in Thailand. Due to a decrease in COVID-19 cases, its application is beneficial when commercial alternatives are unavailable.


Asunto(s)
COVID-19 , Colorimetría , Técnicas de Diagnóstico Molecular , Técnicas de Amplificación de Ácido Nucleico , SARS-CoV-2 , Sensibilidad y Especificidad , Humanos , SARS-CoV-2/genética , SARS-CoV-2/aislamiento & purificación , Técnicas de Amplificación de Ácido Nucleico/métodos , Colorimetría/métodos , Tailandia , COVID-19/diagnóstico , Técnicas de Diagnóstico Molecular/métodos , ARN Viral/genética , ARN Viral/análisis , ARN Viral/aislamiento & purificación , Prueba de Ácido Nucleico para COVID-19/métodos , Nasofaringe/virología
20.
Talanta ; 281: 126889, 2024 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-39288583

RESUMEN

Although porphyrin modification can improve the peroxidase-like activity of some inorganic nanozymes, it is hardly studied that metal porphyrin self-assembled nanoaggregates as sacrificial templates to turn on the peroxidase-like activity of inorganic nanozymes under light illumination. In this work, cobalt (II) 5,10,15,20-Tetrakis (4-carboxylpheyl)porphyrin (CoTCPP) self-assembled nanoaggregates are firstly used as soft templates to prepare TiO2-based nanozymes with the enhanced peroxidase-like activity. Interestingly, CoTCPP nanoaggregates can be changed into Co oxide nanoparticles dispersed into the nanosphere composites. Furthermore, the peroxidase-like activity of CoTCPP-TiO2 nanospheres can be controlled by light illumination. Comparatively, CoTCPP-TiO2 nanoshperes exhibit the highest peroxidase-like activity of three nanospheres (CoTCPP-TiO2, H2TCPP-TiO2 and TiO2) with similar morphology under the light illumination. Other than the existence of oxygen vacancy, the formation of heterostructure between TiO2 and a small amount of Co3O4 are ascribed to increase the catalytic activity of CoTCPP-TiO2 composites. Thus, a facile and convenient colorimetric sensing platform has been constructed and tuned by light illumination for determining H2O2 and amikacin in a good linear range of 20-100 and 50-100 µM with a limit of detection (LOD) of 3.04 µM and 1.88 µM, respectively. The CoTCPP-TiO2 based colorimetric sensing platform has been validated by measuring the amikacin residue in lake water.

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