Molecularly Engineered Surface Triboelectric Nanogenerator by Self-Assembled Monolayers (METS)

Song, Giyoung,Kim, Younghoon,Yu, Seunggun,Kim, Min-Ook,Park, Sang-Hee,Cho, Suk Man,Velusamy, Dhinesh Babu,Cho, Sung Hwan,Kim, Kang Lib,Kim, Jongbaeg,Kim, Eunkyoung,Park, Cheolmin American Chemical Society 2015 Chemistry of materials Vol.27 No.13

<P>Self-powered energy harvesters utilizing triboelectric effect and electrostatic induction have been widely studied, leading in the materials viewpoint to numerous material pairs for facile charge separation upon repetitive contacts with elaborate topological structures. Here, we present a simple but robust triboelectric platform based on a molecularly engineered surface triboelectric nanogenerator by self-assembled monolayers (METS). Triboelectric surface charge density of a substrate was readily controlled by the variation of end-functional groups of self-assembled monolayers (SAMs). In particular, by employing fluorine terminated SAMs, we are able to develop a METS with the maximum open circuit voltage and short circuit current of 105 V and 27 μA, respectively, under relatively gentle mechanical contacts with the 3N vertical force at 1.25 Hz. The power density of the device was 1.8 W/m<SUP>2</SUP> at the load resistance of 10 MΩ more than 60 times greater than that of an unmodified dielectric/Al device. Moreover, our approach with SAMs was extended to various types of surfaces including fabrics of silk, cotton, and poly(ethylene terephthalate) (PET) and a PET film, and the results of single-friction-surface triboelectric nanogenerators with these materials offers a facile and universal guideline for designing triboelectic materials.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/cmatex/2015/cmatex.2015.27.issue-13/acs.chemmater.5b01507/production/images/medium/cm-2015-01507p_0001.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/cm5b01507'>ACS Electronic Supporting Info</A></P>

Applications of Microfluidics in the Agro-Food Sector: A Review

Kim, Giyoung,Lim, Jongguk,Mo, Changyeun Korean Society for Agricultural Machinery 2016 바이오시스템공학 Vol.41 No.2

Background: Microfluidics is of considerable importance in food and agricultural industries. Microfluidics processes low volumes of fluids in channels with extremely small dimensions of tens of micrometers. It enables the miniaturization of analytical devices and reductions in cost and turnaround times. This allows automation, high-throughput analysis, and processing in food and agricultural applications. Purpose: This review aims to provide information on the applications of microfluidics in the agro-food sector to overcome limitations posed by conventional technologies. Results: Microfluidics contributes to medical diagnosis, biological analysis, drug discovery, chemical synthesis, biotechnology, gene sequencing, and ecology. Recently, the applications of microfluidics in food and agricultural industries have increased. A few examples of these applications include food safety analysis, food processing, and animal production. This study examines the fundamentals of microfluidics including fabrication, control, applications, and future trends of microfluidics in the agro-food sector. Conclusions: Future research efforts should focus on developing a small portable platform with modules for fluid handling, sample preparation, and signal detection electronics.

Developoment of A Movable Hyperspectral System for Food Safety Inspection

( Giyoung Kim ),( Changyeun Mo ),( Jongguk Lim ),( Saetbyeul Park ),( Jinyoung Yu ) 한국농업기계학회 2018 한국농업기계학회 학술발표논문집 Vol.23 No.1

Conventional safety evaluation methods for foods are labor-intensive and time consuming. Furthermore, their on-site usage is limited because they still require several lengthy steps, expensive laboratory instruments, and experienced operators. Hyperspectral imaging technology is suitable for rapidly acquiring large amounts of image data with continuous spectrum information. This technology has been widely applied for the quality and safety evaluation of agricultural food products, because it is able to overcome the limits of typical spectroscopy methods that attain spectral information from one point at a time. Hyperspectral imaging technology allows development of rapid methods for simultaneous detection of several contaminants. However, typical hyperspectral imaging systems are usually big and heavy that hinders them from using on-site. This study was conducted to develop movable in-field prototype hyperspectral imaging system for food safety inspection of food processing equipment. The movable hyperspectral imaging system consists of a wheeled rack frame, two gib arms to adjust camera height, a line scan type hyperspectral imaging camera, and a linear motion guide to control the movement of the camera. The movable hyperspectral imaging system successfully acquired hyperspectral images of the surface of the food processing equipment.

A Review on Lateral Flow Test Strip for Food Safety

Kim, Giyoung,Lim, Jongguk,Mo, Changyeun Korean Society for Agricultural Machinery 2015 바이오시스템공학 Vol.40 No.3

Background: Foodborne disease outbreaks from various food sources are a major health concern worldwide. Current methods for detection of foodborne pathogens are both expensive and time-consuming. Purpose: This review aims to present the current information available on the use of lateral flow test strips to detect pathogens in food products to enhance food safety. Results: Frequent foodborne disease outbreaks from various food sources have increased the need for rapid and easy methods for routine analysis of foodborne pathogens. Present detection methods for foodborne pathogens require expensive instruments, experts, and long time for sample analysis. Lateral flow test strips have drawn attention in recent years because of their ability to detect analytes quickly and easily. This review focuses on the principle of the lateral flow test, the various formats of lateral flow test strips, recognition elements, labeling tags, and reading instruments. In addition, this review also discusses the future prospects for the lateral flow test strips.

Applications of Microfluidics in the Agro-Food Sector: A Review

( Giyoung Kim ),( Jongguk Lim ),( Changyeun Mo ) 한국농업기계학회 2016 바이오시스템공학 Vol.41 No.2

Background: Microfluidics is of considerable importance in food and agricultural industries. Microfluidics processes low volumes of fluids in channels with extremely small dimensions of tens of micrometers. It enables the miniaturization of analytical devices and reductions in cost and turnaround times. This allows automation, high-throughput analysis, and processing in food and agricultural applications. Purpose: This review aims to provide information on the applications of microfluidics in the agro-food sector to overcome limitations posed by conventional technologies. Results: Microfluidics contributes to medical diagnosis, biological analysis, drug discovery, chemical synthesis, biotechnology, gene sequencing, and ecology. Recently, the applications of microfluidics in food and agricultural industries have increased. A few examples of these applications include food safety analysis, food processing, and animal production. This study examines the fundamentals of microfluidics including fabrication, control, applications, and future trends of microfluidics in the agro-food sector. Conclusions: Future research efforts should focus on developing a small portable platform with modules for fluid handling, sample preparation, and signal detection electronics.

Development of Rapid Diagnostic Technology for Pig Disease (2) - Rapid detection of PPE in the pig feces -

Kim, Hyuck-Joo,Hong, Jong-Tae,Yu, Byeong-Kee,Kim, Giyoung,Kim, Suk Korean Society for Agricultural Machinery 2013 바이오시스템공학 Vol.38 No.2

Purpose: Porcine proliferative enteropathy (PPE), caused by the obligate intracellular bacterium Lawsonia intracellularis, is a widely distributed disease throughout the world causing substantial economic loss. In order to diagnose PPE rapidly, the rapid kit was developed and tested. Methods: In this study, a rapid kit was developed to screen the PPE rapidly at the pig farm. Also, occult blood test with fecal occult blood (FOB) kit was done for detecting the blood in pig feces which might be the evident of hemorrhagic PPE. For developing the kit, we tested fecal samples of PPE infected pigs diagnosed by polymerase chain reaction (PCR) method. Results: With the developed rapid kit, Lawsonia intracellularis was detected in high density emulsion of ileum. On the other hand, the test result of detecting Lawsonia in feces showed too high non-specific response. In addition, nevertheless the FOB test result showed that blood evident could be founded in pig feces, the diagnosing result was not fit to PCR test result, which shows blood in pig feces could be from not only hemorrhagic PPE but also many reasons. Conclusions: To deal with the PPE effectively, it will be better for farmers to screen the PPE in earlier stage with easy and rapid diagnosing tool on farm. This study found out that the rapid kit could detect the Lawsonia intracellularis and hemoglobin in pig feces. However, the non-specific response to negative samples of PPE was too high to use at a pig farm. Further research is needed for lowering the non-specific response with the rapid kit.

Review on Biosensors for Food Safety

Kim, Giyoung,Moon, Ji-Hea,Lim, Jongguk,Mo, Changyeun Korean Society for Agricultural Machinery 2014 바이오시스템공학 Vol.39 No.2

Background: Frequent outbreaks of foodborne illness have been increased awareness of food safety. CDC estimates that each year roughly 48 million people gets sick, 128,000 are hospitalized and 3,000 die of foodborne diseases in US. In Korea, 6,058 were hospitalized and 266 incidents were reported in 2012. It is required to develop rapid methods to identify hazard substances in food products for protecting and maintaining safety of the public health. However, conventional methods for pathogens detection and identification involve prolonged multiple enrichment steps. Purpose: This review aims to provide information on biosensors to detect pathogens in food products to enhance food safety. Results: Foodborne outbreaks continue to occur and outbreaks from various food sources have increased the need for simple, rapid, and sensitive methods to detect foodborne pathogens. Conventional methods for foodborne pathogens detection require tremendous amount of labor and time. Biosensors have drawn attentions in recent years because of their ability to detect analytes sensitively and rapidly. Principles along with their advantages and disadvantages of a variety of food safety biosensors including fiber optic biosensor, impedimetric biosensor, surface Plasmon resonance biosensor, and nano biosensor were explained. Also, future trends for the food safety biosensors were discussed.

Image Analysis of a Lateral Flow Strip Sensor for the Detection of Escherichia coli O157:H7

Kim, Giyoung,Moon, Ji-Hea,Park, Saet Byeol,Jang, Youn-Jung,Lim, Jongguk,Mo, Changyeun Korean Society for Agricultural Machinery 2013 바이오시스템공학 Vol.38 No.4

Purpose: This study was performed to develop a lateral flow strip sensor for the detection of pathogenic Escherichia coli O157:H7 in various samples. Also, feasibility of using an image analysis method to improve the interpretation of the strip sensor was evaluated. Methods: The lateral flow strip sensor has been fabricated based on nitrocellulose lateral-flow membrane. Colloidal gold and E. coli O157:H7 antibodies were used as a tag and a receptor, respectively. Manually spotted E. coli O157:H7 antibody and anti-mouse antibody on nitrocellulose membrane were used as test and control dots, respectively. Feasibility of the lateral flow strip sensor to detect E. coli O157:H7 were evaluated with serially diluted E. coli O157:H7 cells in PBS or food samples. Test results of the lateral flow strip sensor were measured with an image analysis method. Results: The intensity of the test dot started to increase with higher concentration of the cells were introduced. The sensitivities of the sensor were both $10^4$ CFU/mL Escherichia coli O157:H7 spiked in PBS and in chicken meat extract, respectively. Conclusions: The lateral flow strip sensor and image analysis method could detect E. coli O157:H7 in 20 min, which is significantly quicker than conventional plate counting method.

Rapid Detection of Salmonella enteritidis in Pork Samples with Impedimetric Biosensor

Giyoung Kim,Ji Hea Moon,Bung-Kwon Hahm,Mark Morgan,Arun Bhunia,Ae Son Om 한국식품과학회 2009 Food Science and Biotechnology Vol.18 No.1

Frequent outbreaks of foodborne illness have been increasing the awareness of food safety. Conventional methods for pathogen detection and identification are labor-intensive and take days to complete. Some immunological, rapid assays are developed, but these assays still require prolonged enrichment steps. Recently developed biosensors have shown potential for the rapid detection of foodborne pathogens. In this study, an impedimetric biosensor was developed for rapid detection of Salmonella entritidis in food sample. To develop the biosensor, an interdigitated microelectrode (IME) was fabricated by using a semiconductor fabrication process. Anti-Salmonella antibodies were immobilized based on neutravidin-biotin binding on the surface of the IME to form an active sensing layer. To evaluate the effect of electrode gap on sensitivity of the sensor, 3 types of sensors with different electrode gap sizes (2, 5, and 10 ㎛) were fabricated and tested. The impedimetric biosensor could detect 10³ CFU/㎖ of Salmonella in pork meat extract with an incubation time of 5 min. This method may provide a simple, rapid, and sensitive method to detect foodborne pathogens.

An Automated Fiber-optic Biosensor Based Binding Inhibition Assay for the Detection of Listeria Monocytogenes

Giyoung Kim,Mark Morgan,Daniel Ess,Byoung-Kwon Hahm,Aparna Kothapalli,Arun Bhunia 한국식품과학회 2007 Food Science and Biotechnology Vol.16 No.3

Conventional methods for pathogen detection and identification are labor-intensive and take days to complete. Biosensors have shown great potential for the rapid detection of foodborne pathogens. Fiber-optic biosensors have been used to rapidly detect pathogens because they can be very sensitive and are simple to operate. However, many fiber-optic biosensors rely on manual sensor handling and the sandwich assay, which require more effort and are less sensitive. To increase the simplicity of operation and detection sensitivity, a binding inhibition assay method for detecting Listeria monocytogenes in food samples was developed using an automated, fiber-optic-based immunosensor; RAPTOR (Research International, Monroe, WA, USA). For the assay, fiber-optic biosensorswere developed by the immobilization of Listeria antibodies on polystyrene fiber waveguides through a biotin-avidin reaction. Developed fiber-optic biosensors were incorporated into the RAPTOR to evaluate the detection of L. monocytogenes in frankfurter samples. The binding inhibition method combined with RAPTOR was sensitive enough to detect L. monocytogenes (5.4ⅹ10? CFU/mL) in a frankfurter sample.