Microfluidics refers to a system that manipulates a small amount of fluids ( using small channels with sizes ten to hundreds micrometres. It is a multidisciplinary field that involves molecular analysis, biodefence, molecular biology, and microelectronics. It has practical applications in the design of systems that process low volumes of fluids to achieve multiplexing, automation, and high-throughput screening. Microfluidics emerged in the beginning of the 1980s and is used in the development of inkjet printheads, DNA chips, lab-on-a-chip technology, micro-propulsion, and micro-thermal technologies.
Isoelectric focusing (IEF), also known as electrofocusing, is a technique for separating different molecules by differences in their isoelectric point (pI). It is a type of zone electrophoresis usually performed on proteins in a gel that takes advantage of the fact that overall charge on the molecule of interest is a function of the pH of its surroundings.
Capillary electrophoresis (CE) is a family of electrokinetic separation methods performed in submillimeter diameter capillaries and in micro- and nanofluidic channels. Very often, CE refers to capillary zone electrophoresis (CZE), but other electrophoretic techniques including capillary gel electrophoresis (CGE), capillary isoelectric focusing (CIEF), capillary isotachophoresis and micellar electrokinetic chromatography (MEKC) belong also to this class of methods. In CE methods, analytes migrate through electrolyte solutions under the influence of an electric field. Analytes can be separated according to ionic mobility and/or partitioning into an alternate phase via non-covalent interactions. Additionally, analytes may be concentrated or "focused" by means of gradients in conductivity and pH.
Joseph Wang is an American biomedical engineer and inventor. He is a Distinguished Professor, SAIC Endowed Chair, and former Chair of the Department of Nanoengineering at the University of California, San Diego, who specialised in nanomachines, biosensors, nano-bioelectronics, wearable devices, and electrochemistry. He is also the Director of the UCSD Center of Wearable Sensors and co-director of the UCSD Center of Mobile Health Systems and Applications (CMSA).
Capillary electrophoresis–mass spectrometry (CE–MS) is an analytical chemistry technique formed by the combination of the liquid separation process of capillary electrophoresis with mass spectrometry. CE–MS combines advantages of both CE and MS to provide high separation efficiency and molecular mass information in a single analysis. It has high resolving power and sensitivity, requires minimal volume and can analyze at high speed. Ions are typically formed by electrospray ionization, but they can also be formed by matrix-assisted laser desorption/ionization or other ionization techniques. It has applications in basic research in proteomics and quantitative analysis of biomolecules as well as in clinical medicine. Since its introduction in 1987, new developments and applications have made CE-MS a powerful separation and identification technique. Use of CE–MS has increased for protein and peptides analysis and other biomolecules. However, the development of online CE–MS is not without challenges. Understanding of CE, the interface setup, ionization technique and mass detection system is important to tackle problems while coupling capillary electrophoresis to mass spectrometry.
Affinity electrophoresis is a general name for many analytical methods used in biochemistry and biotechnology. Both qualitative and quantitative information may be obtained through affinity electrophoresis. Cross electrophoresis, the first affinity electrophoresis method, was created by Nakamura et al. Enzyme-substrate complexes have been detected using cross electrophoresis. The methods include the so-called electrophoretic mobility shift assay, charge shift electrophoresis and affinity capillary electrophoresis. The methods are based on changes in the electrophoretic pattern of molecules through biospecific interaction or complex formation. The interaction or binding of a molecule, charged or uncharged, will normally change the electrophoretic properties of a molecule. Membrane proteins may be identified by a shift in mobility induced by a charged detergent. Nucleic acids or nucleic acid fragments may be characterized by their affinity to other molecules. The methods have been used for estimation of binding constants, as for instance in lectin affinity electrophoresis or characterization of molecules with specific features like glycan content or ligand binding. For enzymes and other ligand-binding proteins, one-dimensional electrophoresis similar to counter electrophoresis or to "rocket immunoelectrophoresis", affinity electrophoresis may be used as an alternative quantification of the protein. Some of the methods are similar to affinity chromatography by use of immobilized ligands.
Instrumental analysis is a field of analytical chemistry that investigates analytes using scientific instruments.
Flow focusing in fluid dynamics is a technology whose aim is the production of drops or bubbles by straightforward hydrodynamic means. The output is a dispersed liquid or gas, frequently in the form of a fine aerosol or an emulsion. No other driving force is required, apart from traditional pumping, a key difference with other comparable technologies, such as electrospray. Both flow focusing and electrospray working in their most extensively used regime produce high quality sprays composed by homogeneous and well-controlled-size droplets. Flow focusing was invented by Prof. Alfonso M. Gañan-Calvo in 1994, patented in 1996, and published for the first time in 1998.
David M. Goodall is a British chemist. He is Emeritus Professor of chemistry affiliated with the University of York (UK). Throughout his career he has made a considerable impact on the field of analytical chemistry.
Cynthia Larive is an American scientist and academic administrator serving as the chancellor of University of California, Santa Cruz. Larive's research focuses on nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry. She was previously a professor of chemistry and provost and executive vice chancellor at the University of California, Riverside. She is a fellow of AAAS, IUPAC and ACS, associate editor for the ACS journal Analytical Chemistry and editor of the Analytical Sciences Digital Library.
Daniel Wayne Armstrong is an American chemist who specializes in separation science, chiral molecular recognition, bioanalytic analysis, mass spectrometry and colloid chemistry. He is the Robert A. Welch Distinguished Professor at the University of Texas at Arlington. He has authored ~ 750 publications including 35 book chapters, a book, and holds over 35 patents on separation technologies. He was an associate editor for the prestigious American Chemical Society journal Analytical Chemistry. He is a fellow of the American Chemical Society, Royal Chemical Society (UK), and the National Academy of Inventors. Armstrong has given over 560 invited seminars worldwide at international conferences, universities and corporations. His research and patents formed the basis for two companies: Advanced Separation Technologies, Inc; which was acquires by Sigma-Aldrich Corporation in 2006 and AZYP, LLC in Arlington, TX. His published work has been cited over 50,000 times and his h-index is 115. He is believed to have mentored more graduate level analytical chemists than any living scientist.
Milos Vratislav Novotny is an American chemist, currently the Distinguished Professor Emeritus and Director of the Novotny Glycoscience Laboratory and the Institute for Pheromone Research at Indiana University, and also a published author. Milos Novotny received his Bachelor of Science from the University of Brno, Czechoslovakia in 1962. In 1965, Novotny received his Ph.D. at the University of Brno. Novotny also holds honorary doctorates from Uppsala University, Masaryk University and Charles University, and he has been a major figure in analytical separation methods. Novotny was recognized for the development of PAGE Polyacrylamide Gel-filled Capillaries for Capillary Electrophoresis in 1993. In his years of work dedicated to analytical chemistry he has earned a reputation for being especially innovative in the field and has contributed a great deal to several analytical separation methods. Most notably, Milos has worked a great deal with microcolumn separation techniques of liquid chromatography, supercritical fluid chromatography, and capillary electrophoresis. Additionally, he is highly acclaimed for his research in proteomics and glycoanalysis and for identifying the first mammalian pheromones.
Droplet-based microfluidics manipulate discrete volumes of fluids in immiscible phases with low Reynolds number and laminar flow regimes. Interest in droplet-based microfluidics systems has been growing substantially in past decades. Microdroplets offer the feasibility of handling miniature volumes of fluids conveniently, provide better mixing, encapsulation, sorting, sensing and are suitable for high throughput experiments. Two immiscible phases used for the droplet based systems are referred to as the continuous phase and dispersed phase.
Paper-based microfluidics are microfluidic devices that consist of a series of hydrophilic cellulose or nitrocellulose fibers that transport fluid from an inlet through the porous medium to a desired outlet or region of the device, by means of capillary action. This technology builds on the conventional lateral flow test which is capable of detecting many infectious agents and chemical contaminants. The main advantage of this is that it is largely a passively controlled device unlike more complex microfluidic devices. Development of paper-based microfluidic devices began in the early 21st century to meet a need for inexpensive and portable medical diagnostic systems.
John Michael Ramsey is an American analytical chemist at the University of North Carolina at Chapel Hill. He currently holds the position of Minnie N. Goldby Distinguished Professor of Chemistry. His current research with the university focuses on microscale and nanoscale devices such as microchip electrospray, microscale Ion trap mass spectrometers, and microfluidic point of care devices. He is ranked #2 in the "Giants of Nano" field on The Analytical Scientist Power List.
James Wallace Jorgenson is an American academic who previously held the position of William Rand Kenan Jr. Distinguished Professor of Chemistry at UNC-Chapel Hill. He is best known for his work developing capillary zone electrophoresis, and is a member of the American Academy of Arts and Sciences.
Shelley D. Minteer is an American academic and chemistry professor at the University of Utah. Minteer field of study focuses on the interface between biocatalysts and enzyme-based electrodes for biofuel cells and sensors.
Robert Travis Kennedy is an American chemist specializing in bioanalytical chemistry including liquid chromatography, capillary electrophoresis, and microfluidics. He is currently the Hobart H. Willard Distinguished University Professor of Chemistry and the chair of the department of chemistry at the University of Michigan. He holds joint appointments with the Department of Pharmacology and Department Macromolecular Science and Engineering. Kennedy is an Associate Editor of Analytical Chemistry.
Carlotta Guiducci is an Italian bio-engineer. Her research is invested in bio-molecular analysis based on lab-on-a-chip devices. She is an Associate Professor at EPFL and head of the Laboratory of Life Sciences Electronics located at EPFL's Lausanne campus.
B. Jill Venton is a professor of chemistry at University of Virginia, where she serves as the department chair since 2019. Venton's research focuses on developing analytical chemistry methods to enable detection of molecules in the brain.
