Under-5-Minute Immunoblot Assays by Vortex Fluidic Device Acceleration.

Unlocking the potential of personalized medicine in point-of-care settings requires a new generation of biomarker and proteomic assays. Ideally, assays could inexpensively perform hundreds of quantitative protein measurements in parallel at the bedsides of patients. This goal greatly exceeds current capabilities. Furthermore, biomarker assays are often challenging to translate from benchtop to clinic due to difficulties achieving and assessing the necessary selectivity, sensitivity, and reproducibility. To address these challenges, we developed an efficient (<5 min), robust (comparatively lower CVs), and inexpensive (decreasing reagent use and cost by >70 %) immunoassay method. Specifically, the immunoblot membrane is dotted with the sample and then developed in a vortex fluidic device (VFD) reactor. All assay steps-blocking, binding, and washing-leverage the unique thin-film microfluidics of the VFD. The approach can accelerate direct, indirect, and sandwich immunoblot assays. The applications demonstrated include assays relevant to both the laboratory and the clinic.

Angled Vortex Fluidic Mediated Multicomponent Photocatalytic and Transition Metal-Catalyzed Reactions.

The dynamic thin film formed in an angled rapidly rotating tube in a vortex fluidic device (VFD) is effective in facilitating multicomponent reactions (MCRs) as photocatalytic or metal-mediated processes. Here, we demonstrate the utility of the VFD by using two known MCRs, an Ugi-type three component reaction and an A3 -coupling reaction. The Ugi-type reaction can be done in either confined or continuous-flow modes of operation of the microfluidic platform whereas the A3 -coupling reaction was optimized for the confined mode of operation. The examples tested gave excellent yields with short reaction times.

Vortex Fluidic Chemical Transformations.

Driving chemical transformations in dynamic thin films represents a rapidly thriving and diversifying research area. Dynamic thin films provide a number of benefits including large surface areas, high shearing rates, rapid heat and mass transfer, micromixing and fluidic pressure waves. Combinations of these effects provide an avant-garde style of conducting chemical reactions with surprising and unusual outcomes. The vortex fluidic device (VFD) has proved its capabilities in accelerating and increasing the efficiencies of numerous organic, materials and biochemical reactions. This Minireview surveys transformations that have benefited from VFD-mediated processing, and identifies concepts driving the effectiveness of vortex-based dynamic thin films.

Accelerating Enzymatic Catalysis Using Vortex Fluidics.

Enzymes catalyze chemical transformations with outstanding stereo- and regio-specificities, but many enzymes are limited by their long reaction times. A general method to accelerate enzymes using pressure waves contained within thin films is described. Each enzyme responds best to specific frequencies of pressure waves, and an acceleration landscape for each protein is reported. A vortex fluidic device introduces pressure waves that drive increased rate constants (kcat ) and enzymatic efficiency (kcat /Km ). Four enzymes displayed an average seven-fold acceleration, with deoxyribose-5-phosphate aldolase (DERA) achieving an average 15-fold enhancement using this approach. In solving a common problem in enzyme catalysis, a powerful, generalizable tool for enzyme acceleration has been uncovered. This research provides new insights into previously uncontrolled factors affecting enzyme function.

Chemoselective and Continuous Flow Hydrogenations in Thin Films Using a Palladium Nanoparticle Catalyst Embedded in Cellulose Paper.

Cellulose immobilized palladium (0) nanoparticles (PdNPs) were prepared for the use in scalable catalytic reactions in flow. Preparation of the catalyst is remarkably simple and fast, where a palladium acetate solution is drop-casted onto cellulose paper and then exposed to 1 atm of hydrogen for a mere 90 s to produce embedded Pd(0) nanoparticles. This catalyst system is efficient in the hydrogenation of alkenes, nitroarenes, ketones, and enamides, with products formed in high yields, under ambient pressure and temperature. The system is also effective for transfer hydrogenation using ammonium formate as an alternative hydrogen source. A high catalyst stability and reusability are demonstrated along with the chemoselective and scalable synthesis of industrially important fine chemicals, including the biobased molecule cyrene.

Protein Folding Using a Vortex Fluidic Device.

Essentially all biochemistry and most molecular biology experiments require recombinant proteins. However, large, hydrophobic proteins typically aggregate into insoluble and misfolded species, and are directed into inclusion bodies. Current techniques to fold proteins recovered from inclusion bodies rely on denaturation followed by dialysis or rapid dilution. Such approaches can be time consuming, wasteful, and inefficient. Here, we describe rapid protein folding using a vortex fluidic device (VFD). This process uses mechanical energy introduced into thin films to rapidly and efficiently fold proteins. With the VFD in continuous flow mode, large volumes of protein solution can be processed per day with 100-fold reductions in both folding times and buffer volumes.