Hamed Tavakoli

Bio: Hamed Tavakoli is an academic researcher from Islamic Azad University. The author has contributed to research in topics: Adsorption & Central composite design. The author has an hindex of 13, co-authored 24 publications receiving 747 citations. Previous affiliations of Hamed Tavakoli include Nankai University & Shahid Beheshti University.

Recent advances in microfluidic platforms for single-cell analysis in cancer biology, diagnosis and therapy.

Abstract: Understanding molecular, cellular, genetic and functional heterogeneity of tumors at the single-cell level has become a major challenge for cancer research. The microfluidic technique has emerged as an important tool that offers advantages in analyzing single-cells with the capability to integrate time-consuming and labour-intensive experimental procedures such as single-cell capture into a single microdevice at ease and in a high-throughput fashion. Single-cell manipulation and analysis can be implemented within a multi-functional microfluidic device for various applications in cancer research. Here, we present recent advances of microfluidic devices for single-cell analysis pertaining to cancer biology, diagnostics, and therapeutics. We first concisely introduce various microfluidic platforms used for single-cell analysis, followed with different microfluidic techniques for single-cell manipulation. Then, we highlight their various applications in cancer research, with an emphasis on cancer biology, diagnosis, and therapy. Current limitations and prospective trends of microfluidic single-cell analysis are discussed at the end.

Micromachining a miniaturized capillary electrophoresis-based chemical analysis system on a chip

Abstract: Micromachining technology was used to prepare chemical analysis systems on glass chips (1 centimeter by 2 centimeters or larger) that utilize electroosmotic pumping to drive fluid flow and electrophoretic separation to distinguish sample components. Capillaries 1 to 10 centimeters long etched in the glass (cross section, 10 micrometers by 30 micrometers) allow for capillary electrophoresis-based separations of amino acids with up to 75,000 theoretical plates in about 15 seconds, and separations of about 600 plates can be effected within 4 seconds. Sample treatment steps within a manifold of intersecting capillaries were demonstrated for a simple sample dilution process. Manipulation of the applied voltages controlled the directions of fluid flow within the manifold. The principles demonstrated in this study can be used to develop a miniaturized system for sample handling and separation with no moving parts.

Dispersive liquid-liquid microextraction

Abstract: Dispersive liquid-liquid microextraction (DLLME) is a novel sample-preparation technique offering high enrichment factors from low volumes of water samples. It has found wide acceptance because of several advantages, including simplicity, low cost and ease of method development, which made it available to virtually all analytical laboratories. This review focuses on improvements made in DLLME since its introduction in 2006. We present use of DLLME with simultaneous derivatization of analytes and connection of DLLME to other sample-preparation techniques. We also describe exchange of toxic chlorinated solvents with low toxic hydrocarbons, alcohols and ionic liquids. We include application of DLLME to pre-concentration of metal ions and many more modifications of this newly developed technique. We briefly describe different applications of DLLME to several groups of analytes, including pesticides, pharmaceuticals, phenols and other compounds, and, finally, we predict some future trends.

Nanophotonics-enabled solar membrane distillation for off-grid water purification

Abstract: With more than a billion people lacking accessible drinking water, there is a critical need to convert nonpotable sources such as seawater to water suitable for human use. However, energy requirements of desalination plants account for half their operating costs, so alternative, lower energy approaches are equally critical. Membrane distillation (MD) has shown potential due to its low operating temperature and pressure requirements, but the requirement of heating the input water makes it energy intensive. Here, we demonstrate nanophotonics-enabled solar membrane distillation (NESMD), where highly localized photothermal heating induced by solar illumination alone drives the distillation process, entirely eliminating the requirement of heating the input water. Unlike MD, NESMD can be scaled to larger systems and shows increased efficiencies with decreased input flow velocities. Along with its increased efficiency at higher ambient temperatures, these properties all point to NESMD as a promising solution for household- or community-scale desalination.