scholarly journals Perspectives of Nano-Materials and Nanobiosensors in Food Safety and Agriculture

2021 ◽  
Author(s):  
Sivaji Mathivanan

Nanobiosensor is one type of biosensor made up with usage of nanomaterials i.e., nanoparticles and nanostructures. Because of the nanomaterials’ unique properties such as good conductivity, and physicochemical, electrochemical, optical, magnetic and mechanical properties, Nanobiosensors are highly reliable and more sensitive in biosensing approaches over conventional sensors which is having various limitation in detection. Quantum dots, nanotubes, nanowires, magnetic and other nanoparticles enhance sensitivity and lower limit of detection by amplifying signals and providing novel signal transduction mechanisms enable detection of a very low level of food contaminants, pesticides, foodborne pathogens, toxins and plant metabolites. Nanobiosensors are having a lot of scope in sustainable agriculture because of its detecting ability i.e., sensing changes occurred in molecular level. So it can be utilized to find out the variations or modification of plant metabolities, volatiles, gas exchange, hormonal and ion concentration etc. which are the indicators of various harsh environmental stresses (abiotic), biotic and physiological stress. Identification of the stress in the starting stage itself will help us to avoid intensive plant damage and prevent yield losses created by the stress. Nanosensors can be used in smart farming, in which all the environmental factors related to plant growth like temperature, water, pH, humidity, nutritional factor etc. are measured and precaution taken to control the factors which reduce the crop production with the help of IOT platform, thereby enhance the productivity. In this review, discussed about nanobiosensors for detection of food contaminants and various application and its potential in agriculture.

2019 ◽  
Vol 31 (1) ◽  
pp. 1-9
Author(s):  
Deepak Kumar Sahu ◽  
Joyce Rai ◽  
Chhaya Bhatt ◽  
Manish K. Rai ◽  
Jyoti Goswami ◽  
...  

In modern age pesticide is used widely in agriculture. Lambda-cyhalothrin (LCT) is one of the most used pesticides which are used as a insecticide to kill pest, tricks, flies etc in agricultural field and it is also used for crop production. We have developed new method to detect LCT insecticide in agriculture field and reduce its uses. In this method we found the maximum absorbance at 460 nm for yellow colour dye. We also calculated limit of detection and limit of quantification 0.001 mg kg-1 and 0.056 mg kg-1 respectively. Molar absorptivity and Sandell’s sensitivity was also calculated and obtained 1.782 ×107 mol-1 cm-1 and 9.996 ×10-6 µg cm-2 respectively. The obtained yellow colour dye obeyed Beer’s law limit range of 0.5 µg ml -1 to 16 µg ml-1 in 25 ml. This method is less time consuming, selective, simple, sensitive and low cost. Present method is successfully applied in various soil, water and vegetable samples.


2016 ◽  
Vol 79 (7) ◽  
pp. 1143-1153 ◽  
Author(s):  
JOHN C. FRELKA ◽  
GORDON R. DAVIDSON ◽  
LINDA J. HARRIS

ABSTRACT After harvest, inshell walnuts are dried using low-temperature forced air and are then stored in bins or silos for up to 1 year. To better understand the survival of bacteria on inshell walnuts, aerobic plate counts (APCs) and Escherichia coli–coliform counts (ECCs) were evaluated during commercial storage (10 to 12°C and 63 to 65% relative humidity) over 9 months. APCs decreased by 1.4 to 2.0 log CFU per nut during the first 5 months of storage, and ECCs decreased by 1.3 to 2.2 log CFU per nut in the first month of storage. Through the remaining 4 to 8 months of storage, APCs and ECCs remained unchanged (P > 0.05) or decreased by <0.15 log CFU per nut per month. Similar trends were observed on kernels extracted from the inshell walnuts. APCs and ECCs were consistently and often significantly higher on kernels extracted from visibly broken inshell walnuts than on kernels extracted from visibly intact inshell walnuts. Parameters measured in this study were used to determine the survival of five-strain cocktails of E. coli O157:H7, Listeria monocytogenes, and Salmonella inoculated onto freshly hulled inshell walnuts (~8 log CFU/g) after simulated commercial drying (10 to 12 h; 40°C) and simulated commercial storage (12 months at 10°C and 65% relative humidity). Populations declined by 2.86, 5.01, and 4.40 log CFU per nut for E. coli O157:H7, L. monocytogenes, and Salmonella, respectively, after drying and during the first 8 days of storage. Salmonella populations changed at a rate of −0.33 log CFU per nut per month between days 8 and 360, to final levels of 2.83 ± 0.79 log CFU per nut. E. coli and L. monocytogenes populations changed by −0.17 log CFU per nut per month and −0.26 log CFU per nut per month between days 8 and 360, respectively. For some samples, E. coli or L. monocytogenes populations were below the limit of detection by plating (0.60 log CFU per nut) by day 183 or 148, respectively; at least one of the six samples was positive at each subsequent sampling time by either plating or by enrichment.


Author(s):  
Murat Soyseven ◽  
Rüstem Keçili ◽  
Hassan Y Aboul-Enein ◽  
Göksel Arli

Abstract A novel analytical method, based on high-performance liquid chromatography with a UV (HPLC-UV) detection system for the sensitive detection of a genotoxic impurity (GTI) 5-amino-2-chloropyridine (5A2Cl) in a model active pharmaceutical ingredient (API) tenoxicam (TNX), has been developed and validated. The HPLC-UV method was used for the determination of GTI 5A2Cl in API TNX. The compounds were separated using a mobile phase composed of water (pH 3 adjusted with orthophosphoric acid): MeOH, (50:50: v/v) on a C18 column (150 × 4.6 mm i.d., 2.7 μm) at a flow rate of 0.7 mL min−1. Detection was carried out in the 254 nm wavelength. Column temperature was maintained at 40°C during the analyses and 10 μL volume was injected into the HPLC-UV system. The method was validated in the range of 1–40 μg mL−1. The obtained calibration curves for the GTI compound was found linear with equation, y = 40766x − 1125,6 (R2 = 0.999). The developed analytical method toward the target compounds was accurate, and the achieved limit of detection and limit of quantification values for the target compound 5A2Cl were 0.015 and 0.048 μg mL−1, respectively. The recovery values were calculated and found to be between 98.80 and 100.03%. The developed RP-HPLC-UV analytical method in this research is accurate, precise, rapid, simple and appropriate for the sensitive analysis of target GTI 5A2Cl in model API TNX.


2015 ◽  
Vol 78 (9) ◽  
pp. 1632-1641 ◽  
Author(s):  
GINA RYAN ◽  
SHERRY ROOF ◽  
LAURIE POST ◽  
MARTIN WIEDMANN

Assays for detection of foodborne pathogens are generally initially evaluated for performance in validation studies carried out according to guidelines provided by validation schemes (e.g., AOAC International or the International Organization for Standardization). End users often perform additional validation studies to evaluate the performance of assays in specific matrices (e.g., specific foods or raw material streams of interest) and with specific pathogen strains. However, these types of end-user validations are typically not well defined. This study was conducted to evaluate a secondary end user validation of four AOAC-validated commercial rapid detection assays (an isothermal nucleic acid amplification, an immunoassay, and two PCR-based assays) for their ability to detect Salmonella in two challenging matrices (dry pet food and dark chocolate). Inclusivity was evaluated with 68 diverse Salmonella strains at low population levels representing the limit of detection (LOD) for each assay. One assay detected all strains at the LOD, two assays detected multiple strains only at 10 times the LOD, and the fourth assay failed to detect two strains (Salmonella bongori and S. enterica subsp. houtenae) even at 1,000 times the LOD; this assay was not further evaluated. The three remaining assays were subsequently evaluated for their ability to detect five selected Salmonella strains in food samples contaminated at fractional levels. Unpaired comparisons revealed no significant difference between the results for each given assay and the results obtained with the reference assay. However, analysis of paired culture-confirmed results revealed assay false-negative rates of 4 to 26% for dry pet food and 12 to 16% for dark chocolate. Overall, our data indicate that rapid assays may have high false-negative rates when performance is evaluated under challenging conditions, including low-moisture matrices, strains that are difficult to detect, injured cells, and low inoculum levels.


Electronics ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 347 ◽  
Author(s):  
Maria Chiriacò ◽  
Ilaria Parlangeli ◽  
Fausto Sirsi ◽  
Palmiro Poltronieri ◽  
Elisabetta Primiceri

A great improvement in food safety and quality controls worldwide has been achieved through the development of biosensing platforms. Foodborne pathogens continue to cause serious outbreaks, due to the ingestion of contaminated food. The development of new, sensitive, portable, high-throughput, and automated platforms is a primary objective to allow detection of pathogens and their toxins in foods. Listeria monocytogenes is one common foodborne pathogen. Major outbreaks of listeriosis have been caused by a variety of foods, including milk, soft cheeses, meat, fermented sausages, poultry, seafood and vegetable products. Due to its high sensitivity and easy setup, electrochemical impedance spectroscopy (EIS) has been extensively applied for biosensor fabrication and in particular in the field of microbiology as a mean to detect and quantify foodborne bacteria. Here we describe a miniaturized, portable EIS platform consisting of a microfluidic device with EIS sensors for the detection of L. monocytogenes in milk samples, connected to a portable impedance analyzer for on-field application in clinical and food diagnostics, but also for biosecurity purposes. To achieve this goal microelectrodes were functionalized with antibodies specific for L. monocytogenes. The binding and detection of L. monocytogenes was achieved in the range 2.2 × 103 cfu/mL to 1 × 102 with a Limit of Detection (LoD) of 5.5 cfu/mL.


2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Tan Ling Ling ◽  
Musa Ahmad ◽  
Lee Yook Heng

An amperometric electrochemical biosensor has been developed for ammonium (NH4+) ion detection by immobilising alanine dehydrogenase (AlaDH) enzyme in a photocurable methacrylic membrane made up of poly(2-hydroxyethyl methacrylate) (pHEMA) on a screen-printed carbon paste electrode (SPE). The current detected was based on the electrocatalytic oxidation of nicotinamide adenine dinucleotide reduced (NADH) that is proportional to the consumption ofNH4+ion whilst enzymatic amination of AlaDH and pyruvate is taking place. The biosensor was operated amperometrically at a potential of +0.6 V and optimum pH 7. TheNH4+biosensor demonstrated linear response toNH4+ion concentration in the range of 0.03–1.02 mg/L with a limit of detection (LOD) of 8.52 μg/L. The proposed method has been successfully applied to the determination ofNH4+ion in river water samples without any pretreatment. The levels of possible interferents in the waters were negligible to cause any interference on the proposed method. The analytical performance of the biosensor was comparable to the colorimetric method using Nesslerisation but with much lower detection limit and linear response range at ppb level.


2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Mayooreshwar P Rajankar ◽  
Sapna Ravindranathan ◽  
P R Rajamohanan ◽  
Anu Raghunathan

Abstract Poly(R)-3-hydroxybutyric acid (PHB) is a biodegradable natural polymer produced by microorganisms and plants under nitrogen deprivation and physiological stress. Metabolic engineering and synthetic biology approaches are underway to develop strains that can produce PHB and its co-polymers. One of the major limitations to the scaling and success of strain development for biosynthesis of PHB is the absence of fast, accurate, quantitative and scalable methods to estimate PHB in polymer producing cells. In this study, a Nile red-based spectrofluorometric method is developed for absolute quantitation of PHB in recombinant Escherichia coli. The method is a modification of an existing Nile red-based method currently only used for relative quantitation. The two added steps of sonication and ethanol extraction increase the dynamic range of the assay and limit of detection/quantitation. Sonication of PHB standards provides uniform distribution of surface area to volume ratios. This ensures reproducibility and accuracy (lower %relative error) of quantitative staining of granules by Nile red even in a higher dynamic concentration range of 125–1000 µg/ml. Ethanolic extraction of the PHB bound Nile red allows higher recovery and accurate absolute quantitation. To reproduce high recovery and ensure accuracy and precision of the analytical method directly using cells, a protein digestion step was added. This accounted for fluorescence from over-expressed protein and resulted in screening of nonproducers of PHB amongst samples. Thus, the method developed is rapid, accurate, and reproducible, requires low sample volumes and processing compared to other conventional methods. This method is scalable to other PHA’s and diverse plastics.


Author(s):  
Preksha Patel ◽  
Manan Raval ◽  
Nidhi Patel ◽  
Samir Patel ◽  
Niraj Vyas ◽  
...  

Abstract Background Roots of Argyreia speciosa (Linn. F) Sweet (family: Convolvulaceae) are used in Ayurveda to treat male reproductive and nervous system disorders. Objective Isolation of scopoletin from the roots of Argyreia speciosa, development and validation of an analytical method using HPLC for the quantification of scopoletin from the root powder of Argyreia speciosa. Method Scopoletin was isolated from chloroform fraction prepared from hydrolyzed methanolic extract and identified using spectral studies. A reverse-phase HPLC based analytical method was developed and optimized using the DoE approach to estimate scopoletin from the roots of Argyreia speciosa. Scopoletin was separated and quantified using HPLC containing C18 column and a PDA detector. The optimized mobile phase was methanol: water (pH∼3.2) [25: 75, %v/v]. Results The Box-Behnken design was used to optimize chromatographic parameters and the extraction procedure. The validation studies showed a linear relationship (r2=0.998) in the range of 1–40 µg/ml. The limit of Detection and Limit of Quantification were found to be 0.28 µg/ml and 0.84 µg/ml, respectively and the recovery values were found between 91.94 to 97.86%. The developed analytical method was found robust too. The amount of scopoletin was estimated to be 0.024 ± 0.0016%w/w from dried root powder. Conclusion The recorded chromatogram and amount of scopoletin determined would serve as one of the standardization parameters to access the quality of raw material containing Argyreia speciosa. Highlights Developed analytical method may be adopted as a part of the standardization procedure for Argyreia speciosa in the quality control laboratory.


Pathogens ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1391
Author(s):  
Rebecca L. Bell ◽  
Julie A. Kase ◽  
Lisa M. Harrison ◽  
Kannan V. Balan ◽  
Uma Babu ◽  
...  

Water is vital to agriculture. It is essential that the water used for the production of fresh produce commodities be safe. Microbial pathogens are able to survive for extended periods of time in water. It is critical to understand their biology and ecology in this ecosystem in order to develop better mitigation strategies for farmers who grow these food crops. In this review the prevalence, persistence and ecology of four major foodborne pathogens, Shiga toxin-producing Escherichia coli (STEC), Salmonella, Campylobacter and closely related Arcobacter, and Listeria monocytogenes, in water are discussed. These pathogens have been linked to fresh produce outbreaks, some with devastating consequences, where, in a few cases, the contamination event has been traced to water used for crop production or post-harvest activities. In addition, antimicrobial resistance, methods improvements, including the role of genomics in aiding in the understanding of these pathogens, are discussed. Finally, global initiatives to improve our knowledge base of these pathogens around the world are touched upon.


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