Development of paper-based microfluidic devices for environmental and food quality analysis, The

Includes bibliographical references.2016 Fall.Providing safe and nutritious food and water, both domestically and internationally, has long been a goal for improving global health. Recent legislations enacted within the United States have enabled government agencies to further regulate agricultural and industry standards, necessitating the need for more preventative approaches with regards to food and beverage quality and safety. Increasing detection speed and enabling field and production detection of point-source contamination are crucial to maintaining food and beverage safety as well as preventing detrimental disease outbreaks, such as those caused by bacterial contamination. The development of simple, inexpensive, and portable methods for detecting contamination indicators are key to reaching this goal. Moreover, recent developments into microfluidic approaches for analysis have shown great promise as platforms for providing faster simplified methods for detection. The work conducted within this dissertation focuses on the development of simple, inexpensive and disposable platforms for colorimetric and electrochemical analysis of food and beverage quality. Aside from more commonly studied polymer-based devices, recent advances in paper-based diagnostics have demonstrated use as an analytical platform capable of self-pumping, reagent storage, mixing, and implementation of various detection motifs. Herein, the development of microfluidic paper-based analytical devices (μPADs) is presented as a platform for the colorimetric detection of bacteria in food and water samples. Initial work was conducted for the paper-based, colorimetric detection of Listeria monocytogenes, Salmonella Typhimurium, and E. coli O157:H7 bacteria species, all of which have been associated with fatal, multistate food- and waterborne outbreaks. Detection was performed on ready-to-eat meats using a swabbing technique to collect and quickly culture surface contamination of bacteria using enzymatic assays within paper-based microwells. A scanner was used for imaging followed by use of image analysis software for semi-quantitative measurement determination. This method was further applied to the detection of bacteria in irrigation water, a known source of foodborne contamination, using a 3D-printed filter for collection and culture of bacteria present in low concentrations within water. Although colorimetric detection offers a simple, visual detection method, electrochemistry is an alternative, sensitive and portable method for detection. Use of common office materials such as transparency film and copy paper, as well as laboratory filter papers were studied and developed for optimal electrochemical platform performance. The use of microwires as a simple fabrication method for incorporating metallic or modified metallic electrodes into electrochemical paper-based devices (ePADs) was also developed. Electrochemical behavior in both well-based and flow-based ePADs was studied and implemented for the nonenzymatic detection of sugars in beverages using copper oxide modified microwires, and for the in-line flow detection of enzymatic assays using gold and platinum microwire electrodes respectively. Furthermore, the fast, inexpensive, and simple fabrication of carbon stencil-printed electrodes (CSPEs) on transparency film were demonstrated for the electrochemical detection of E. coli and Enterococci bacteria species, both indicators of fecal contamination, in food and water samples using enzymatic assays. These same assays could also be determined colorimetrically and a more portable cell phone was used to image and wirelessly send paper-based well-plate results. This method was developed for use in place of a more bulky and expensive plate reader, and results were used for comparison to electrochemical detection of bacteria from a single assay

An all-glass microfluidic network with integrated amorphous silicon photosensors for on-chip monitoring of enzymatic biochemical assay

A lab-on-chip system, integrating an all-glass microfluidics and on-chip optical detection, was developed and tested. The microfluidic network is etched in a glass substrate, which is then sealed with a glass cover by direct bonding. Thin film amorphous silicon photosensors have been fabricated on the sealed microfluidic substrate preventing the contamination of the micro-channels. The microfluidic network is then made accessible by opening inlets and outlets just prior to the use, ensuring the sterility of the device. The entire fabrication process relies on conventional photolithographic microfabrication techniques and is suitable for low-cost mass production of the device. The lab-on-chip system has been tested by implementing a chemiluminescent biochemical reaction. The inner channel walls of the microfluidic network are chemically functionalized with a layer of polymer brushes and horseradish peroxidase is immobilized into the coated channel. The results demonstrate the successful on-chip detection of hydrogen peroxide down to 18 mu M by using luminol and 4-iodophenol as enhancer agent

Absorbance based light emitting diode optical sensors and sensing devices

The ever increasing demand for in situ monitoring of health, environment and security has created a need for reliable, miniaturised sensing devices. To achieve this, appropriate analytical devices are required that possess operating characteristics of reliability, low power consumption, low cost, autonomous operation capability and compatibility with wireless communications systems. The use of light emitting diodes (LEDs) as light sources is one strategy, which has been successfully applied in chemical sensing. This paper summarises the development and advancement of LED based chemical sensors and sensing devices in terms of their configuration and application, with the focus on transmittance and reflectance absorptiometric measurements

Pressure-Driven Filling of Closed-End Microchannel: Realization of Comb-Shaped Transducers for Acoustofluidics

We demonstrate the complete filling of both deionized water (DI water) and liquid metal (eutectic gallium-indium, EGaIn) into closed-end microchannels driven by a constant pressure at the inlet. A mathematical model based on gas diffusion through a porous polydimethylsiloxane (PDMS) wall is developed to unveil the physical mechanism in the filling process. The proposed theoretical analysis based on our model agrees well with the experimental observations. We also successfully generate traveling surface acoustic waves by actuating interdigitated microchannels filled with EGaIn. Our work provides significant insights into the fabrication of liquid electrodes that can be used for various acustofluidics applicationsAustralian Research Council DE170100600National Natural Science Foundation of China Grants No. 11472094, No. 11772259, No. U1613227, No. B1703

Integrated microfluidic tmRNA purification and real-time NASBA device for molecular diagnostics.

We demonstrate the first integrated microfluidic tmRNA purification and nucleic acid sequence-based amplification (NASBA) device incorporating real-time detection. The real-time amplification and detection step produces pathogen-specific response in < 3 min from the chip-purified RNA from 100 lysed bacteria. On-chip RNA purification uses a new silica bead immobilization method. On-chip amplification uses custom-designed high-selectivity primers and real-time detection uses molecular beacon fluorescent probe technology; both are integrated on-chip with NASBA. Present in all bacteria, tmRNA (10Sa RNA) includes organism-specific identification sequences, exhibits unusually high stability relative to mRNA, and has high copy number per organism; the latter two factors improve the limit of detection, accelerate time-to-positive response, and suit this approach ideally to the detection of small numbers of bacteria. Device efficacy was demonstrated by integrated on-chip purification, amplification, and real-time detection of 100 E. coli bacteria in 100 microL of crude lysate in under 30 min for the entire process

Integration of Microfluidic Devices and Smart Phones for Water Monitoring –A Review

Microfluidic innovation permits analytical system to be scaled down and incorporated into lab-on-a-chip devices, minimizing the volume of reagents consumed and of waste created, and permitting the utilization of low-fueled pumping system. Here, in this survey we will ponder the microfluidic sensors able to do quick, multiplexed detection. Electrochemical detection in a microfluidic stage offers numerous focal points, for example, compactness, insignificant utilization of instrumentation, and simple integration with electronics. In numerous parts of the world, be that as it may, the required gear for detection through electrochemical sensors is either not available or inadequately compact, and administrators may not be prepared to utilize these sensors and translate results, at last keeping its wide adoption. Presently a days, step by step the versatile innovation is growing quick. Joining these sort of versatile electrochemical procedures with such quickly developing advances will give advantage to the community. Toward a solution to water quality interventions, individuals have effectively demonstrate a microfluidic electrochemical sensor joined with a portable interface that identifies the different water contaminants and contaminations, appropriate for quick, reasonable, and point-of-care water monitoring. In this survey, we will first give the general foundation of microfluidic-based detection, versatile innovations available in combination with microfluidic sensors, and their integration

อุปกรณ์การวิเคราะห์บนกระดาษด้วยระบบของไหลจุลภาคสำหรับตรวจหายาปนปลอม ในสมุนไพรและอาหารเสริม Microfluidic Paper-based Analytic Device (µPAD) for Detection of Adulterated Drugs in Herbal and Dietary Supplements

บทคัดย่อ อุปกรณ์การวิเคราะห์บนกระดาษด้วยระบบของไหลจุลภาคประดิษฐ์ขึ้นโดยการสร้างกระดาษให้มีลวดลายซึ่งประกอบด้วยช่องไหลที่มีคุณสมบัติชอบน้ำ (หรือบริเวณโซนทดสอบ) คั่นด้วยขอบเขตที่มีคุณสมบัติไม่ชอบน้ำเพื่อควบคุมทิศทางการไหล คุณสมบัติการซึมน้ำและความพรุนของกระดาษเอื้อให้ของไหลไหลผ่านไปตามช่องโดยอาศัยเพียงคะปิลลารีแอกชัน อุปกรณ์กระดาษที่มีการออกแบบอย่างเหมาะสมสามารถนำมาประยุกต์ใช้ในงานวิเคราะห์สาขาต่าง ๆ บทความนี้นำเสนอภาพรวมโดยสังเขปเกี่ยวกับแนวทางการพัฒนาอุปกรณ์การวิเคราะห์บนกระดาษ ครอบคลุมการเลือกชนิดกระดาษ วิธีการสร้างอุปกรณ์และเทคนิคการตรวจวัดสารที่นิยมใช้ เน้นตัวอย่างของการพัฒนาอุปกรณ์เพื่อตรวจหายาแผนปัจจุบันปนปลอมในสมุนไพรและอาหารเสริม อุปกรณ์กระดาษมีข้อดีหลายประการทั้งด้านความประหยัดของต้นทุน ใช้สารเคมีปริมาณน้อยที่ระดับจุลภาค เป็นมิตรต่อสิ่งแวดล้อม ความสะดวกในการใช้งานและความรวดเร็ว คำสำคัญ: อุปกรณ์การวิเคราะห์บนกระดาษด้วยระบบของไหลจุลภาค, ยาปนปลอม, สมุนไพรและอาหารเสริม Abstract The microfluidic paper analytical device (µPAD) is fabricated by creating a patterned paper consisting of hydrophilic flow channels (or assay zones) separated by hydrophobic boundaries to control the flow direction. The wicking property and the porosity of paper facilitate the passive flow of fluids through the channel via capillary action. A well-designed µPAD can be applied in various analytical fields. This paper offers a brief review of the approaches for µPAD development, including the selection of paper types, design and fabrication method, and detection techniques commonly used, emphasizing the example of µPAD development for the detection of adulterated drugs in herbal and dietary supplements. Several advantages of µPAD are cost savings, the use of small amounts of reagent at the micro level, environmental friendliness, ease of use, and speed. Keywords: microfluidic paper-based analytic device (µPAD), adulterated drugs, herbal and dietary supplement

Paper-based microfluidic devices for food adulterants: Cost-effective technological monitoring systems

Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGAnalytical sciences have witnessed emergent techniques for efficient clinical and industrial food adulterants detection. In this review, the contributions made by the paper-based devices are highlighted for efficient and rapid detection of food adulterants and additives, which is the need of the hour and how different categories of techniques have been developed in the past decade for upgrading the performance for point-of-care testing. A simple strategy with an arrangement for detecting specific adulterants followed by the addition of samples to obtain well-defined qualitative or quantitative signals for confirming the presence of target species. The paperbased microfluidics-based technology advances and prospects for food adulterant detection are discussed given the high-demand from the food sectors and serve as a valued technology for food researchers working in interdisciplinary technological frontiers.Vision Group on Science and Technology, Government of Karnataka | Ref. KSTePS/ VGST/SMYSR-2016–17/GRD-595/2017–18Vision Group on Science and Technology, Government of Karnataka | Ref. KSTePS/VGSTRGS/F/GRD No.711/2017–18Science and Engineering Research Board (SERB), Department of Science and Technology, Govt of India | Ref. CRG/2020/00306

Smartphone as a Portable Detector, Analytical Device, or Instrument Interface

The Encyclopedia Britannia defines a smartphone as a mobile telephone with a display screen, at the same time serves as a pocket watch, calendar, addresses book and calculator and uses its own operating system (OS). A smartphone is considered as a mobile telephone integrated to a handheld computer. As the market matured, solid-state computer memory and integrated circuits became less expensive over the following decade, smartphone became more computer-like, and more more-advanced services, and became ubiquitous with the introduction of mobile phone networks. The communication takes place for sending and receiving photographs, music, video clips, e-mails and more. The growing capabilities of handheld devices and transmission protocols have enabled a growing number of applications. The integration of camera, access Wi-Fi, payments, augmented reality or the global position system (GPS) are features that have been used for science because the users of smartphone have risen all over the world. This chapter deals with the importance of one of the most common communication channels, the smartphone and how it impregnates in the science. The technological characteristics of this device make it a useful tool in social sciences, medicine, chemistry, detections of contaminants, pesticides, drugs or others, like so detection of signals or image