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Full-Text Articles in Life Sciences
The Impact Of A Non-Ionic Adjuvant To The Persistence Of Pesticides On Produce Surfaces, Daniel Barnes
The Impact Of A Non-Ionic Adjuvant To The Persistence Of Pesticides On Produce Surfaces, Daniel Barnes
Masters Theses
Adjuvants can enhance the performance of the pesticide active ingredients in many ways including decreasing surface tension and reducing evaporation. Understanding how adjuvants effect pesticide behavior (e.g., surface persistence) is crucial for developing effective pesticide formulations, as well as facilitating the development of effective approaches to reduce pesticide residues from the surface of fresh produce post-harvest. The objective of this study is to investigate the effect of a non-ionic surfactant, Surf-Ac 910, on the persistence of two model pesticides, thiabendazole and phosmet on apple surfaces. The result shows that the addition of Surf-Ac 910 increased both the maximum wetted area …
Detection Of Mycotoxins Using Surface-Enhanced Raman Spectroscopy, Lourdes B. Martinez Rojas
Detection Of Mycotoxins Using Surface-Enhanced Raman Spectroscopy, Lourdes B. Martinez Rojas
Doctoral Dissertations
Mycotoxins are toxic metabolites produced by fungus that can be parasites or saprophytes of crops or livestock forage. Consumer demand for plant-based foods and interest in animal-based foods originating from animals fed plant-based feed has been on the rise. Therefore, monitoring mycotoxins occurring in the food supply is more critical than ever. The goal of this project is to improve surface-enhanced Raman spectroscopy’s (SERS) ability to identify and detect mycotoxins using label-free SERS substrates. Two simple approaches were designed to enhance the detection of mycotoxins produced by the Aspergillus and Penicillium genera, ochratoxin A and aflatoxin B1. Ochratoxin A was …
Analysis Of Plant And Animal Proteins Using Raman Spectroscopy, Noopur Bapardekar
Analysis Of Plant And Animal Proteins Using Raman Spectroscopy, Noopur Bapardekar
Masters Theses
There has been a notable rise in the alternative protein market in the recent years which promotes an interest in the research of both animal and plant proteins to establish better structure-function relationships. Over the years many analytical tools have been used to study proteins and compare them, however Raman Spectroscopy and Surface Enhanced Raman Spectroscopy (SERS) have not been as much used for this application. SERS consolidates Raman Spectroscopy that primarily measures molecular vibrations and nanostructures that enhance the weak Raman signals. The objective of this study is to explore the capability of the Raman instrumentation in combination with …
Antibiotic Sensitivity Testing Of Foodborne Bacteria Using Surface-Enhanced Raman Spectroscopy, Joshua Gukowsky
Antibiotic Sensitivity Testing Of Foodborne Bacteria Using Surface-Enhanced Raman Spectroscopy, Joshua Gukowsky
Doctoral Dissertations
The spread of antibiotic resistant bacteria around the world has become a major public health issue, and it is essential that effective detection methods exist for identifying these organisms and preventing them from spreading throughout our food systems and into the environment. The goal of this research is to develop a novel analytical procedure that is capable of easily identifying antibiotic resistance in bacterial samples, and also provides more information about the biochemical characteristics of the bacteria and their responses to antibiotic exposure. Surface-enhanced Raman Spectroscopy (SERS), an analytical technique that uses light scattering to produce a spectrum based on …
Silver Mirror Substrate And Rolling Method For Improved Surface-Enhanced Raman Spesctroscopic Analysis In Food, Yanqi Qu
Doctoral Dissertations
Surface-enhanced Raman spectroscopy, short for SERS, is an emerging technology with great potential in food analysis due to rapid detection, high sensitivity, portable instrumentation, and simple sample preparation. However, it is always a bottleneck to obtain reproducible SERS measurements in real analytical cases due to the complicity of food systems and inhomogeneous aggregation of colloidal nanoparticles. To improve its performance for practical applications in food analysis, efforts have been made in improving the reproducibility, enhancing the selectivity and reducing the matrix interference to the analyte. Herein, a self-assembly silver nanoparticles mirror substrate was fabricated to improve the and the quantitative …
Surface-Enhanced Raman Spectroscopic Imaging Of Bacteria Within Fresh Produce In Situ, Michael Hickey
Surface-Enhanced Raman Spectroscopic Imaging Of Bacteria Within Fresh Produce In Situ, Michael Hickey
Doctoral Dissertations
The growth curves for E. coli O157:H7 (#043888) are reported. We make the case that the onset of stationary growth is the optimal point at which a bacteria culture is considered suitable for quantitative Raman analyses. The optimal conditions for 3-mercaptophenylboronic acid coating of bacteria cells is also reported. Fundamental drawbacks of the status-quo approach have been elucidated and overcome, based on measurable improvements to the experimental methodology. This approach is shown to be suitable for the evaluation of bacterial rinse-washing efficacy by means of Raman light-scattering. The data were compared to label-free applications and the measurable differences between each …
In Situ And Real-Time Monitoring And Characterization Of Pesticide Residues On And In Fresh Produce Using Sers, Tianxi Yang
In Situ And Real-Time Monitoring And Characterization Of Pesticide Residues On And In Fresh Produce Using Sers, Tianxi Yang
Doctoral Dissertations
Understanding of the behavior and fate of pesticides in fresh produce is of great significance for effectively applying pesticides and minimizing pesticide residues in food. There is lack, however, of an effective method that can monitor and characterize pesticide behaviors including penetration, persistence and translocation. Herein, we developed a novel method for real-time and in situ monitoring of pesticide behaviors in fresh produce based on surface-enhanced Raman scattering (SERS) mapping method. Taking advantage of penetrative gold nanoparticles as probes to enhance the internalized pesticide signals, the internal signals from pesticides were successfully obtained in situ. We found that systemic pesticides …
Label-Free And Aptamer-Based Surface Enhanced Raman Spectroscopy For Detection Of Food Contaminants, Shintaro Pang
Label-Free And Aptamer-Based Surface Enhanced Raman Spectroscopy For Detection Of Food Contaminants, Shintaro Pang
Doctoral Dissertations
The development of analytical methods to detect food contaminants is a critical step for improving food safety. Surface enhanced Raman spectroscopy (SERS) is an emerging detection technology that has the potential to rapidly, accurately and sensitively detect a wide variety of food contaminants. However, SERS detection becomes a challenge in real complex matrix, such as food, since non-specific matrix signals have the potential to drown out target associated Raman peaks. In this dissertation, we focused on the development and application of label-free, aptamer-based SERS in order to improve the accuracy and specificity of target contaminant detection in food. To accomplish …
Investigate The Interactions Between Silver Nanoparticles And Spinach Leaf By Surface Enhanced Raman Spectroscopic Mapping, Zhiyun Zhang
Investigate The Interactions Between Silver Nanoparticles And Spinach Leaf By Surface Enhanced Raman Spectroscopic Mapping, Zhiyun Zhang
Masters Theses
Owing to their increasing application and potential toxicity, engineered nanoparticles (ENPs) have been considered as a potential agricultural contaminant that may pose unknown risk to human beings. However, many techniques require invasive and complicated sample preparation procedures to detect and characterize engineered nanomaterials in complex matrices. In the first part of this thesis, we present a non-destructive and label-free approach based on surface enhanced Raman spectroscopic (SERS) mapping technique to qualitatively detect and characterize gold nanoparticles (AuNPs), on and in spinach leaves in situ. We were able to detect the clearly enhanced signals from AuNPs at 15 to 125 nm …