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1.
Foods ; 13(7)2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38611387

RESUMO

Panax notoginseng (P. notoginseng) is a valuable herbal medicine, as well as a dietary food supplement known for its satisfactory clinical efficacy in alleviating blood stasis, reducing swelling, and relieving pain. However, the ability of P. notoginseng to absorb and accumulate cadmium (Cd) poses a significant environmental pollution risk and potential health hazards to humans. In this study, we employed laser-induced breakdown spectroscopy (LIBS) for the rapid detection of Cd. It is important to note that signal uncertainty can impact the quantification performance of LIBS. Hence, we proposed the crater-spectrum feature fusion method, which comprises ablation crater morphology compensation and characteristic peak ratio correction (CPRC), to explore the feasibility of signal uncertainty reduction. The crater morphology compensation method, namely, adding variables using multiple linear regression (MLR) analysis, decreased the root-mean-square error of the prediction set (RMSEP) from 7.0233 µg/g to 5.4043 µg/g. The prediction results were achieved after CPRC pretreatment using the calibration curve model with an RMSEP of 3.4980 µg/g, a limit of detection of 1.92 µg/g, and a limit of quantification of 6.41 µg/g. The crater-spectrum feature fusion method reached the lowest RMSEP of 2.8556 µg/g, based on a least-squares support vector machine (LSSVM) model. The preliminary results suggest the effectiveness of the crater-spectrum feature fusion method for detecting Cd. Furthermore, this method has the potential to be extended to detect other toxic metals in addition to Cd, which significantly contributes to ensuring the quality and safety of agricultural production.

2.
Anal Sci ; 40(4): 581-597, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38367162

RESUMO

The domains of cancer therapy, disease prevention, and health care greatly benefit from the use of herbal medicine. Herbal medicine has become the mainstay of developing characteristic agriculture in the planting area increasing year by year. One of the most significant factors in affecting the quality of herbal medicines is the pesticide residue problem caused by pesticide abuse during the cultivation of herbal medicines. It is urgent to solve the problem of detecting pesticide residues in herbal medicines efficiently and rapidly. In this review, we provide a comprehensive description of the various methods used for pesticide residue testing, including optical detection, the enzyme inhibition rate method, molecular detection methods, enzyme immunoassays, lateral immunochromatographic, nanoparticle-based detection methods, colorimetric immunosensor, chemiluminescence immunosensor, smartphone-based immunosensor, etc. On this basis, we systematically analyze the mechanisms and some of the findings of the above detection strategies and discuss the challenges and prospects associated with the development of pesticide residue detection tools.


Assuntos
Técnicas Biossensoriais , Medicamentos de Ervas Chinesas , Resíduos de Praguicidas , Plantas Medicinais , Resíduos de Praguicidas/análise , Medicina Herbária , Medicamentos de Ervas Chinesas/análise , Imunoensaio , Tecnologia
3.
Biosens Bioelectron ; 236: 115417, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37244084

RESUMO

Total antioxidant capacity (TAC) has become an important index to evaluate the food quality. Effective antioxidant detection has been the research hotspot of scientists. In this work, a novel three-channel colorimetric sensor array founded on Au2Pt bimetallic nanozymes for the discrimination of antioxidants in food was constructed. Benefiting from the unique bimetallic doping structure, Au2Pt nanospheres exhibited the excellent peroxidase-like activity with Km of 0.044 mM and Vmax of 19.37 × 10-8 M s-1 toward TMB. The density functional theory (DFT) calculation revealed that Pt atom in the doping system was active sites and there was no energy barrier in catalytic reaction which made Au2Pt nanospheres had excellent catalytic activity. Accordingly, a multifunctional colorimetric sensor array was constructed based on Au2Pt bimetallic nanozymes for rapid and sensitive detection of five antioxidants. Based on the different reduction ability of antioxidants, oxidized TMB could be reduced in different degrees. In the presence of H2O2, the colorimetric sensor array could generate differential colorimetric signals (fingerprints) by using TMB as the chromogenic substrate, which could be accurately discriminated through linear discriminant analysis (LDA) with a detection limit of <0.2 µM. The sensor array was able to the evaluate TAC in three actual samples (milk, green tea and orange juice). Furthermore, we prepared a rapid detection strip to meet the needs of practical application, making a positive contribution to food quality evaluation.


Assuntos
Antioxidantes , Técnicas Biossensoriais , Antioxidantes/análise , Colorimetria , Peróxido de Hidrogênio/análise , Chá
4.
Front Plant Sci ; 14: 1128300, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37025139

RESUMO

Herbs have been used as natural remedies for disease treatment, prevention, and health care. Some herbs with functional properties are also used as food or food additives for culinary purposes. The quality and safety inspection of herbs are influenced by various factors, which need to be assessed in each operation across the whole process of herb production. Traditional analysis methods are time-consuming and laborious, without quick response, which limits industry development and digital detection. Considering the efficiency and accuracy, faster, cheaper, and more environment-friendly techniques are highly needed to complement or replace the conventional chemical analysis methods. Infrared (IR) and Raman spectroscopy techniques have been applied to the quality control and safety inspection of herbs during the last several decades. In this paper, we generalize the current application using IR and Raman spectroscopy techniques across the whole process, from raw materials to patent herbal products. The challenges and remarks were proposed in the end, which serve as references for improving herb detection based on IR and Raman spectroscopy techniques. Meanwhile, make a path to driving intelligence and automation of herb products factories.

5.
Food Chem ; 400: 134037, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36055146

RESUMO

2-tert-butyl-1,4-benzoquinone (TBBQ) is the major oxidative product of tert-butylhydroquinone which is a widely used antioxidant in edible oils. The biotoxicity of TBBQ is a risk to human health, that the rapid and accurate monitoring of TBBQ is needed. Herein, a specific chromogenic reaction between TBBQ and polyethyleneimine (PEI) could generate adducts with maximum absorption at 478 nm. Amine groups of PEI are prone to link with TBBQ through Michael addition to form colored adducts. A colorimetric method for detecting TBBQ in edible oils was developed based on the aforesaid chromogenic reaction. The linear range for TBBQ was from 3.0 to 100.0 µg g-1, having a limit of detection of 1.8 µg g-1. Recoveries results ranged from 88.4 % to 93.1 %, which had a good agreement with that of high-performance liquid chromatography. Our study provides a rapid and simple strategy for the sensitive detection of TBBQ using commercial chemicals.


Assuntos
Antioxidantes , Colorimetria , Aminas , Antioxidantes/análise , Benzoquinonas , Cromatografia Líquida de Alta Pressão , Humanos , Óleos de Plantas/química , Polietilenoimina
6.
Artigo em Chinês | WPRIM | ID: wpr-953938

RESUMO

Safety is the core of the quality of Chinese materia medica products, and microbial pollution caused by medicinal materials, decoction pieces, intermediate products and others can bring certain impact on the quality and safety of Chinese materia medica products. The reasons for this are not only the problems of medicinal materials themselves, but also the exogenous pollution introduced in the production process. How to effectively use microbial detection technology and establish an appropriate microbial quality control strategy in the whole process of Chinese materia medica production is of great significance to improve the quality of Chinese materia medica products. Therefore, the authors put forward a microbial quality control strategy in the whole process of Chinese materia medica production based on the guidance of quality by design (QbD) concept, emphasizing the scientific linkage between the internal and external microbial quality control systems to jointly ensure the quality of products in all aspects. Among them, the internal microbial quality control system includes the control of the whole chain of Chinese materia medica-decoction pieces-intermediate products-excipitents-packaging materials-final products, which should be carried out by stages and characteristics, while the external microbial quality control system includes the control of personnel-equipment and facilities-pharmaceutical water-environment, emphasizing the principle of quality risk management and the development of monitoring programs, aiming to closely integrate microbial quality risk management with the production process of Chinese materia medica products, and to classify and develop microbial control strategies in order to minimize the impact of contaminating microorganisms and effectively guarantee the quality of Chinese materia medica products.

7.
Acta Pharmaceutica Sinica ; (12): 2890-2899, 2023.
Artigo em Chinês | WPRIM | ID: wpr-999036

RESUMO

Aiming at the hysteresis and destructiveness of off-line static detection of critical quality attribute of the moisture content of the raw material unit of the traditional Chinese medicine manufacturing process, honey-processed Tussilago farfara, honey-processed Astragalus and honey-processed Glycyrrhiza uralensis were used as the research carriers, and the drying method was used to measure the moisture content as a reference value. The moving stage was used to simulate the movement process of samples on the conveyor belt in the actual on-site production process, and near-infrared (NIR) spectra were collected, combined with machine learning, to establish NIR on-site dynamic detection model of moisture content in multi-variety honey-processed Chinese herbal slice. The results show that the second derivative method is used to preprocess the spectrum. The number of decision trees (ntree), the number of random features (max feature), and the minimum number of samples for generating leaf nodes (node size) are selected: 46, 76, and 8, respectively. The quantitative analysis model of moisture content has the best effect. The prediction coefficient of determination (the prediction coefficient of determination, R2pre) and the root mean square error of prediction (root mean square error of prediction, RMSEP) of the model were 0.903 2 and 0.330 2, respectively. The NIR quantitative model for the moisture content of multi-variety honey-processed Chinese herbal slice established in this study has good predictive performance, and can achieve rapid, accurate and non-destructive quantitative analysis of the moisture content of honey-processed Tussilago farfara, honey-processed Astragalus and honey-processed Glycyrrhiza uralensis at the same time, and provides a method for determining the moisture content of honey-processed Chinese herbal slice of the raw material unit of the traditional Chinese medicine manufacturing process.

8.
World J Microbiol Biotechnol ; 39(2): 52, 2022 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-36564678

RESUMO

This work embodies the development of a real time loop mediated isothermal amplification (RealAmp) assay for the rapid detection of the cryptic tea phytopathogen, Exobasidium vexans, the causal organism of blister blight disease. Due to the widespread popularity of tea as a beverage and the associated agro-economy, the rapid detection and management of the fast-spreading blister blight disease have been a longstanding necessity. Loop-mediated isothermal amplification (LAMP) primers were designed targeting the E. vexans ITS rDNA region and the reaction temperature was optimized at 62 °C with a 60 min reaction time. Amplification of the E. vexans isolates in the initial LAMP reactions was confirmed by both agarose gel electrophoresis and SYBR Green I dye based colour change visualization. The specificity of the LAMP primers for E. vexans was validated by negative testing of seven different phytopathogenic test fungi using LAMP and RealAmp assay. The positive findings in RealAmp assay for E. vexans strain were corroborated via detecting fluorescence signals in real-time. Further, the LAMP assays performed with gDNA isolated from infected tea leaves revealed positive amplification for the presence of E. vexans. The results demonstrate that this rapid and precise RealAmp assay has the potential to be applied for field-based detection of E. vexans in real-time.


Assuntos
Basidiomycota , Técnicas de Amplificação de Ácido Nucleico , Técnicas de Amplificação de Ácido Nucleico/métodos , Basidiomycota/genética , Primers do DNA/genética , Doenças das Plantas/microbiologia , Chá , Sensibilidade e Especificidade
9.
Spectrochim Acta A Mol Biomol Spectrosc ; 274: 121009, 2022 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-35248853

RESUMO

Rapidly and accurately detect the total nitrogen (TN) concentration is enormously important for surface water protection considering the critical role it plays in reflecting the eutrophication of surface water. However, traditional TN detection methods have to experience a tedious oxygen digestion process, which tremendously limits the detection speed of TN. To solve this problem, we propose a novel online rapid TN detection method. The transformations of nitrogenous substances during the oxidative digestion process are observed by using ultraviolet (UV) spectroscopy and the concentration of TN can be predicted by only using the variation of spectrum in the early oxygen digestion process. To select the most informative variables hidden in the collected three-dimension spectrum, a new wavelength selection algorithm called spatial interval permutation combination population analysis (siPCPA) is proposed, which considers the spatial-temporal relationships among each variable in the spectrum. By using the real surface water samples collected from Houhu Lake, Changsha, China, the effectiveness of our proposed new detection and selection methods are verified and compared with other state-of-the-art methods. As a result, the practical application experiment shows that our methods can determine the concentration of TN in 5 min with a relative error of less than 5%.


Assuntos
Nitrogênio , Poluentes Químicos da Água , China , Monitoramento Ambiental/métodos , Lagos , Nitrogênio/análise , Oxigênio , Fósforo , Água/análise , Poluentes Químicos da Água/análise
10.
Zhongguo Zhong Yao Za Zhi ; 46(22): 5736-5743, 2021 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-34951161

RESUMO

The medicinal plants with roots and rhizomes as the medicinal parts account for about 1/3 of Chinese medicinal herbs. Root and rhizome medicinal materials are widely used in clinical practice, whereas their wild resource reserves are insufficient to meet the market demand. With the expansion of planting areas, the formation of large-scale production areas, and the increase in planting years, diseases and insect pests of these medicinal plants, which are diverse and have broad transmission routes, strong concealment, and heavy damage, have become more and more serious. The prevention and control of these diseases and insect pests is characterized by multiple ways of pesticide application, large consumption of pesticides, susceptibility to soil barrier, difficulty in the control, and unstable control efficiency. Organophosphorus pesticides(OPPs) are widely used in the cultivation of Chinese medicinal plants because of their diverse varieties, broad-spectrum, good efficacy, and low residues, and have a positive effect on the yield and quality of Chinese medicinal materials. However, the abuse of OPPs not only increases the planting cost, but also affects the quality and safety of Chinese medicinal plants, the safety of clinical use of Chinese medicine, and the ecological safety of production areas. This paper reviewed the research and development progress of OPPs, the registration status of OPPs used in root and rhizome medicinal materials, residue limit standards, residue status, and rapid detection technology progress of OPPs. This review aims to provide research ideas and references for standardizing the use of OPPs in root and rhizome medicinal materials, reducing OPP residues, and establishing a fast, efficient, accurate, and reliable method for the detection of OPP residues in Chinese herbal medicine.


Assuntos
Resíduos de Praguicidas , Praguicidas , Plantas Medicinais , Compostos Organofosforados , Resíduos de Praguicidas/análise , Praguicidas/análise , Rizoma/química
11.
Zhongguo Zhong Yao Za Zhi ; 46(22): 5861-5866, 2021 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-34951176

RESUMO

The indirect competitive enzyme-linked immunosorbent assay(ic-ELISA) and direct competitive enzyme-linked immunosorbent assay(dc-ELISA) were performed for the rapid detection of aflatoxin B_1(AFB_1) in Astragali Radix, Zingiberis Rhizoma Recens, Jujubae Fructus, and Nelumbinis Semen with self-made antigens and antibodies. Different extraction methods were investigated to reduce the matrix effects of different medicinal parts in Chinese herbal medicines. The sensitivity of dc-ELISA method was improved by optimizing the molar ratio of AFB_1 to horseradish peroxidase(HRP). In this study, the sensitivity(IC_(50)) of ic-ELISA and dc-ELISA was 0.046 and 0.023 ng·mL~(-1), with the limit of detection(LOD) of 0.007 and 0.004 ng·mL~(-1), respectively. The detection time was 3 h and 50 min for ic-ELISA and dc-ELISA, respectively. The recovery rates were within the range of 62.96%-104.4%, with RSDs of less than 10%. Confirmed by LC-MS/MS, three positive samples of Nelumbinis Semen were detected from 53 samples. Two ELISA methods established in this study were accurate, rapid and sensitive, and can be used for rapid screening of AFB_1 in Chinese herbal medicines such as Astragali Radix, Zingiberis Rhizoma Recens, Jujubae Fructus, and Nelumbinis Semen. In addition, the advantages and limitations of the two methods were compared and discussed, which can provide a reference for the testing institutions to choose the proper method.


Assuntos
Aflatoxina B1 , Espectrometria de Massas em Tandem , Aflatoxina B1/análise , China , Cromatografia Líquida , Ensaio de Imunoadsorção Enzimática
12.
Biosensors (Basel) ; 11(6)2021 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-34201167

RESUMO

Food detection technologies play a vital role in ensuring food safety in the supply chains. Conventional food detection methods for biological, chemical, and physical contaminants are labor-intensive, expensive, time-consuming, and often alter the food samples. These limitations drive the need of the food industry for developing more practical food detection tools that can detect contaminants of all three classes. Raman spectroscopy can offer widespread food safety assessment in a non-destructive, ease-to-operate, sensitive, and rapid manner. Recent advances of Raman spectroscopic methods further improve the detection capabilities of food contaminants, which largely boosts its applications in food safety. In this review, we introduce the basic principles of Raman spectroscopy, surface-enhanced Raman spectroscopy (SERS), and micro-Raman spectroscopy and imaging; summarize the recent progress to detect biological, chemical, and physical hazards in foods; and discuss the limitations and future perspectives of Raman spectroscopic methods for food safety surveillance. This review is aimed to emphasize potential opportunities for applying Raman spectroscopic methods as a promising technique for food safety detection.


Assuntos
Contaminação de Alimentos , Inocuidade dos Alimentos/métodos , Análise Espectral Raman/métodos , Suplementos Nutricionais
13.
Front Chem ; 9: 709487, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34249876

RESUMO

Peroxidases are species-specific. Differences in peroxidase can objectively reflect the genetics among species. The use of peroxidase to assist in species identification is relatively simple and effective. In this work, we proposed a graphene-modified electrode. This electrode can amplify the signal of electrocatalytic reduction of hydrogen peroxide. Since peroxidase can catalyze the reduction of hydrogen peroxide, this signal can be used as an indicator to demonstrate the content of peroxidase in different plant tissues. Twelve herbal medicines were selected for our study. The results show that this electrochemical-based detection technique was comparable to colorimetric method in terms of accuracy.

14.
Zhongguo Zhong Yao Za Zhi ; 46(1): 62-71, 2021 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-33645053

RESUMO

Chinese medicinal material is the foundation of traditional Chinese medicine(TCM) industry. Its quality is not only closely related to the health of residents but also the key to the development of the TCM industry. Pesticide residues, heavy metals and mycotoxins are the major pollutants of Chinese medicinal materials. In recent years, quite a number of rapid detection methods for pollutants have been constructed. Among them, surface-enhanced Raman scattering(SERS), which has been widely used in food chemistry, environmental analysis, and other fields because of its speediness and non-destructiveness, shows its great potential in the pollutant detection in Chinese medicinal material. This paper firstly reviews the application of SERS for the detection of common pollutants in Chinese medicinal material. We then discussed the characteristics and advantages of SERS technique for pesticide detection, including the principle, SERS substrate design, specific recognition, etc. Finally, simultaneous detection of multiple pesticide residues in Chinese medicinal material was explored.


Assuntos
Poluentes Ambientais , Resíduos de Praguicidas , China , Medicina Tradicional Chinesa , Resíduos de Praguicidas/análise , Análise Espectral Raman
15.
Artigo em Chinês | WPRIM | ID: wpr-921692

RESUMO

The medicinal plants with roots and rhizomes as the medicinal parts account for about 1/3 of Chinese medicinal herbs. Root and rhizome medicinal materials are widely used in clinical practice, whereas their wild resource reserves are insufficient to meet the market demand. With the expansion of planting areas, the formation of large-scale production areas, and the increase in planting years, diseases and insect pests of these medicinal plants, which are diverse and have broad transmission routes, strong concealment, and heavy damage, have become more and more serious. The prevention and control of these diseases and insect pests is characterized by multiple ways of pesticide application, large consumption of pesticides, susceptibility to soil barrier, difficulty in the control, and unstable control efficiency. Organophosphorus pesticides(OPPs) are widely used in the cultivation of Chinese medicinal plants because of their diverse varieties, broad-spectrum, good efficacy, and low residues, and have a positive effect on the yield and quality of Chinese medicinal materials. However, the abuse of OPPs not only increases the planting cost, but also affects the quality and safety of Chinese medicinal plants, the safety of clinical use of Chinese medicine, and the ecological safety of production areas. This paper reviewed the research and development progress of OPPs, the registration status of OPPs used in root and rhizome medicinal materials, residue limit standards, residue status, and rapid detection technology progress of OPPs. This review aims to provide research ideas and references for standardizing the use of OPPs in root and rhizome medicinal materials, reducing OPP residues, and establishing a fast, efficient, accurate, and reliable method for the detection of OPP residues in Chinese herbal medicine.


Assuntos
Compostos Organofosforados , Resíduos de Praguicidas/análise , Praguicidas/análise , Plantas Medicinais , Rizoma/química
16.
Artigo em Chinês | WPRIM | ID: wpr-921707

RESUMO

The indirect competitive enzyme-linked immunosorbent assay(ic-ELISA) and direct competitive enzyme-linked immunosorbent assay(dc-ELISA) were performed for the rapid detection of aflatoxin B_1(AFB_1) in Astragali Radix, Zingiberis Rhizoma Recens, Jujubae Fructus, and Nelumbinis Semen with self-made antigens and antibodies. Different extraction methods were investigated to reduce the matrix effects of different medicinal parts in Chinese herbal medicines. The sensitivity of dc-ELISA method was improved by optimizing the molar ratio of AFB_1 to horseradish peroxidase(HRP). In this study, the sensitivity(IC_(50)) of ic-ELISA and dc-ELISA was 0.046 and 0.023 ng·mL~(-1), with the limit of detection(LOD) of 0.007 and 0.004 ng·mL~(-1), respectively. The detection time was 3 h and 50 min for ic-ELISA and dc-ELISA, respectively. The recovery rates were within the range of 62.96%-104.4%, with RSDs of less than 10%. Confirmed by LC-MS/MS, three positive samples of Nelumbinis Semen were detected from 53 samples. Two ELISA methods established in this study were accurate, rapid and sensitive, and can be used for rapid screening of AFB_1 in Chinese herbal medicines such as Astragali Radix, Zingiberis Rhizoma Recens, Jujubae Fructus, and Nelumbinis Semen. In addition, the advantages and limitations of the two methods were compared and discussed, which can provide a reference for the testing institutions to choose the proper method.


Assuntos
Aflatoxina B1/análise , China , Cromatografia Líquida , Ensaio de Imunoadsorção Enzimática , Espectrometria de Massas em Tandem
17.
Artigo em Chinês | WPRIM | ID: wpr-878912

RESUMO

Chinese medicinal material is the foundation of traditional Chinese medicine(TCM) industry. Its quality is not only closely related to the health of residents but also the key to the development of the TCM industry. Pesticide residues, heavy metals and mycotoxins are the major pollutants of Chinese medicinal materials. In recent years, quite a number of rapid detection methods for pollutants have been constructed. Among them, surface-enhanced Raman scattering(SERS), which has been widely used in food chemistry, environmental analysis, and other fields because of its speediness and non-destructiveness, shows its great potential in the pollutant detection in Chinese medicinal material. This paper firstly reviews the application of SERS for the detection of common pollutants in Chinese medicinal material. We then discussed the characteristics and advantages of SERS technique for pesticide detection, including the principle, SERS substrate design, specific recognition, etc. Finally, simultaneous detection of multiple pesticide residues in Chinese medicinal material was explored.


Assuntos
China , Poluentes Ambientais , Medicina Tradicional Chinesa , Resíduos de Praguicidas/análise , Análise Espectral Raman
18.
J Hazard Mater ; 402: 123781, 2021 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-33254792

RESUMO

A rapid and ultrasensitive method for colourimetric/photothermal dual-readout detection was developed using an 808 nm NIR laser and a thermal imaging app on mobile phone. Norfloxacin was used as a model contaminant to demonstrate this universal rapid detection method. It is innovatively, to use the advanced two-dimensional material black phosphorus as a colourimetric/photothermal reagent for the first time. The samples were added to the strip, and the analytes were selectively captured on the conjugate pad by monoclonal antibody-modified magnetic/upconversion nanocomposites. The samples flowed through the strips by capillary action until reaching the control line, where immune complex formation occurred due to the presence of secondary antibody. The added black phosphorus could be captured by the the antigens which were directly exposed to the test line and a brown band could be observed by naked eye. Upon illumination by NIR light for 1 min, the real-time temperature is obtained for quantitative analysis through the thermal imaging performed by mobile phone camera. This method can achieve the detection of norfloxacin in water samples within 20 min, and the detection limits of colorimetric and photothermal readout can reach 45 pg mL-1. Compared with conventional strips, this method provided an increased sensitivity by about two orders of magnitude, with a integrated portable laser and a mobile phone. It is a valuable method for rapid detection and can be applied to other environmental contaminants as well.


Assuntos
Colorimetria , Norfloxacino , Cromatografia de Afinidade , Limite de Detecção , Fósforo , Rios , Água
19.
J Vet Med Sci ; 82(7): 875-880, 2020 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-32448815

RESUMO

Polymerase chain reaction (PCR) is typically used for the early detection of mycoplasma in bovine milk; it requires 3 days to obtain results because of the necessary enrichment process. A more rapid, simple, and accurate detection method is required to directly detect the Mycoplasma bovis (M. bovis) gene in milk. In this study, we assess the utility of combining the following two methods to achieve this goal: the loop-mediated isothermal amplification (LAMP), which is more sensitive than PCR, and the procedure for ultra rapid extraction (PURE), which adsorbs and filters components that inhibit DNA amplification/detection. LAMP was examined using DNA extracts obtained by four methods. This showed that PURE had the highest sensitivity and specificity and that the combination of PURE and LAMP was able to detect M. bovis in milk. We then showed that the detection limit of M. bovis was 102 colony-forming units per milliliter of milk using the PURE-LAMP. Finally, the respective sensitivities of the PURE-LAMP and PCR were 57% and 86% for bulk tank milk, 89% and 74% for mature milk, 85% and 92% for colostrum/transitional milk, and 97% and 95% for mastitis milk. The specificity was 100% for all milk samples in both LAMP and PCR. We conclude that PCR was suitable for detecting mycoplasma in bulk tank milk and that the PURE-LAMP could detect mycoplasma within 2 hr and was also effective for mature and mastitis milk.


Assuntos
Leite/microbiologia , Técnicas de Diagnóstico Molecular/veterinária , Infecções por Mycoplasma/veterinária , Mycoplasma bovis/isolamento & purificação , Técnicas de Amplificação de Ácido Nucleico/veterinária , Animais , Bovinos , Colostro/microbiologia , DNA Bacteriano/isolamento & purificação , Feminino , Microbiologia de Alimentos/métodos , Mastite Bovina/diagnóstico , Mastite Bovina/microbiologia , Técnicas de Diagnóstico Molecular/métodos , Infecções por Mycoplasma/diagnóstico , Mycoplasma bovis/genética , Técnicas de Amplificação de Ácido Nucleico/métodos , Reação em Cadeia da Polimerase/veterinária , Sensibilidade e Especificidade
20.
Int J Food Microbiol ; 316: 108440, 2020 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-31733520

RESUMO

Salmonella is the causative agent of many outbreaks related to spice consumption. However, because of the antimicrobial properties of various spices which hinders recovery and detection, Salmonella detection in spices remains a challenge. The objective of this study was to optimize an enrichment broth for Salmonella growth in different spices and tea, in order to maintain an adequate pH and decrease the antimicrobial effects of spices during Salmonella enrichment and subsequent detection. Salmonella contaminated spice and tea dried samples were prepared and the detection of Salmonella was assessed using the developed broth and automated DNA extraction and RT-PCR. Double strength Buffered Peptone Water (BPW) was used to maintain pH, and L-cysteine and DL-serine were added to the broth to reduce the effects of antimicrobial compounds in spices. The modified enrichment broth allowed the growth of Salmonella from each spice sample. Sample to broth ratios varied from 1:9 (garlic powder, chili peppers and tea), to 1:20 (cinnamon). The pH value of each enrichment varied but remained above 4.8. The addition of L-cysteine (30 mmol/L) allowed Salmonella recovery and growth in garlic and onion samples and the addition of DL-serine (11.23 mmol/L) allowed the recovery and growth in cinnamon. The results indicated that Salmonella detection was achieved in <24 h in the modified (BPW + L-cysteine and DL-serine) enrichment broth followed by detection by RT-PCR. This protocol could allow for a more rapid, robust, and sensitive enrichment method for Salmonella in spices.


Assuntos
Microbiologia de Alimentos/métodos , Salmonella/isolamento & purificação , Especiarias/microbiologia , Chá/microbiologia , Capsicum/microbiologia , Cinnamomum zeylanicum/microbiologia , Meios de Cultura/química , Alimentos em Conserva/microbiologia , Alho/microbiologia , Cebolas/microbiologia , Salmonella/genética , Salmonella/crescimento & desenvolvimento
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