Electrospinning and electrospray are both nano-scale material fabrication techniques, based on related phenomena of electrically charged fluid spray from a droplet of liquid. Material is dissolved in liquid, then a spray is generated by applying a high voltage, creating an electric field, between the fluid dispensing capillary and a grounded...
A novel approach for the colorimetric detection of creatinine in a paper/polycaprolactone hybrid microfluidic device using alkaline3,5-dinitrobenzoate (DNB) is described. The reaction parameters of reagent concentration, alkalinity, and analysis time are optimized for fast reaction times and high color yield. Microfluidic devices incorporating this assay are designed and fabricated to...
The detection of biomolecules is critical for clinical diagnostics but requires specialty labor and high cost. The use of microfluidic paper-based analytical devices (µPADs) for bioassays is simpler and cheaper but has low sensitivity. Improved immobilization of antibodies onto cellulose is demonstrated through surface functionalization with APTES and glutaraldehyde. The...
The concept of reducing laboratory operations in scale such that they fit on a microfluidic chip has been met with great enthusiasm. Lab-on-a-chip devices promise to be cost effective to operate due to reduced reagent consumption, have the potential to offer shorter analysis times due to their short path lengths,...
Two improvements to the established procedures for synthesis and response detection of ion-selective optical sensors (optodes) were introduced.
The first improvement addresses the drawback of organic dye (optode-localized chromoionophore) photobleaching. This positively impacts fluorescence response and allows for (1) direct measurement of hydrogen ion activity upon binding with the dye,...
The concept of reducing laboratory operations into microfluidic devices has been an attractive area of research for several decades. Due to several advantages of porous-media microfluidic devices including low mass, portability, power-free fluid transport, and the ability to store dried reagents in the porous structures, these devices show great promise...
A simple Janus-type membrane-based wicking microfluidic device fabricated on a polycaprolactone-filled glass microfiber membrane enables separation and collection of blood plasma or serum from whole blood. This device bridges the wicking and cut-capillary-based solution transport mechanisms in a single membrane. The initial portion of the device is fabricated using selective...
Gene synthesis is an important tool in molecular biology. However, the current
bench-top method of gene synthesis is a costly, time-intensive and reagent-consuming
process. Lab-on-chip technology has many benefits over current bench top methods.
Microchips consume smaller reagent volumes, are reusable and less expensive to make.
This thesis explores the...
Analytical chemistry is an area of chemistry primarily focused on the study and use of instruments for separation, identification, and quantification of an analyte of interest. Specifically, separation science within analytical chemistry often refers to the process of dividing mixtures into their small component parts based on differences in their...
Miniaturized and portable microfluidic analytical platforms have been widely explored in the broad field of chemical analysis. The concept of microfluidics offer a number of important advantages, including low reagent consumption, low-cost detection, high sample throughput, and shorter analysis time. Semiconductor nanocrystals or quantum dots have been extensively utilized in...
The development of simple, rapid, and sensitive methods for thiophenol detection is of great importance in various fields, including environmental monitoring and food quality. Here, we present a novel approach for the colorimetric detection of thiophenols using gold nanoparticles (AuNPs) as the sensing platform. AuNPs aggregate in the presence of...
The development of micro total analysis systems (µTAS), also called “lab-on-a-chip”, or microfluidic analysis systems, is presented in this dissertation. Various research areas, covering subjects from magnetic particles synthesis to novel microchip fabrication techniques, are explored to develop a lab-on-a-chip system capable of performing magnetic bead-based bioassays. These devices are...
There has been a tremendous growth in interest in carbon nanodots (C-dots) in the past several years. As a nascent nanomaterial, C-dots have shown great promise in applications that benefit from their superior water dispersibility, low toxicity, non-blinking fluorescent output, chemical and biological compatibility, ease of functionalization and resistance to...
A system of Photoactuated Droplet Microfluidics (PDM), in which a droplet of
fluid is moved by way of the manipulation of the wettability of a spiropyran
functionalized surface via irradiation with ultraviolet and visible light, was proposed. The
photochromic behaviors of several species of spiropyran were studied and a procedure...
The emerging field of nanotechnology strictly requires the micro-scaling of the available separation technology and the design of novel devices for separations of molecules of interest. The separation of proteins and nanoparticles is challenging due to their relatively large size, non-specific adherence to surfaces and instability in many solvents.
This...
The challenges prompted by miniaturization of chromatographic systems have led scientists to explore new avenues in the synthesis of stationary phases. Packed capillary columns have found limited application in routine analysis due to a number of technical difficulties, most of which are attributable to the frits. New column designs insure...
Due to a number of disadvantages associated with the use of antibodies as
affinity stationary phases, researchers have recently began to explore the use of RNA
and DNA aptamers for use as affinity stationary phases. These molecules have been
shown to be a viable choice for applications in many methods...
Over the last decade, the miniaturization of analytical systems has become an increasingly important and interesting research area. Miniaturized systems offer many advantages, including reduced reagent and sample consumption, shorter analysis times, portability and disposability. This dissertation describes novel approaches in this direction, focusing on two areas: the miniaturization of...
High Performance Liquid Chromatography-Mass Spectrometry coupled with filtration, centrifugation, and other common sample preparation techniques offers a rapid and robust method for separating and quantifying propofol, a commonly used anesthetic, from human blood and its synthetic analogs. Method development is important for not only optimizing separation and quantification for a...
The development of microfluidic devices for heavy metal extraction is presented in this dissertation. Various research areas, covering subjects from photochromic compound syntheses to microchip fabrication techniques are explored to develop microfluidic devices capable of extracting heavy metal ions from drinking water. Through integration of the beneficial characteristics of both...
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Vincent T. Remcho
The development of microfluidic devices for heavy metal extraction is