High-throughput activity screening and sorting of single catalyst particles with a droplet microreactor using dielectrophoresis

Abstract

Solid catalysts are complex, multi-component materials with large interparticle heterogeneities that hamper statistically relevant in-depth catalyst characterization. Here we introduce an automated high-throughput screening and sorting method for catalyst particles. A droplet microreactor was developed for fluorescence-activated sorting of catalyst particles using dielectrophoresis. Fluid catalytic cracking (FCC) particles stained with styrene derivatives were analysed with the analytical platform developed and sorted based on catalytic activity. Highly active and low-to-moderately active catalyst particles were sorted using 4-fluorostyrene or 4-methoxystyrene as probe, respectively. FCC particles were encapsulated in liquid droplets, where fluorescent FCC particles activated the dielectrophoretic sorter and were sorted within 200 ms. Post-sorting analysis of 4-fluorostyrene-stained and sorted catalyst particles was done using fluorescence microscopy and micro-X-ray fluorescence. This confirmed that the sorted particles were the least deactivated and showed the highest acidity, while non-sorted particles contained more metal poisons.

Greatly Enhanced CTC Culture Enabled by Capturing CTC Heterogeneity Using a PEGylated PDMS–Titanium–Gold Electromicrofluidic Device with Glutathione-Controlled Gentle Cell Release

“…In the absence of an electric field, the cells move with the capture medium at high speed in the flow zones (FZs, Movie S1 (30 frames per second (fps)), the bottom-right sketch in Figure a, and Figure S1b), leading to low capture efficiency. When a patterned (3 s on and 3 s off) electric peak-to-peak voltage ( V pp ) of 200 V with a frequency of 200 kHz is applied via the two copper electrodes, a dielectrophoresis (DEP) force is generated on the cells to move them from the FZs (spaces with high flow speed and low electric field) into the virtual (i.e., without a physical boundary) capture zones (CZs, pocketed spaces with low flow speed and high electric field, Movie S2 (30 fps), the bottom-right sketch in Figure a, and Figure S1b), which was also theoretically shown with force analysis in the literature. ,− It is worth noting that DEP has been investigated as an important technique for microfluidic manipulation of various biological particles including living cells. − In addition, the electric field strength due to the voltage (200 V) applied on the capture medium (made of nonconductive water and sugars) across the main channel (∼5 mm in width) is ∼4 × 10 4 V m –1 , which is more than 1000 times lower than the dielectric field strength of water ((65–70) × 10 6 V m –1 ), , the maximum electric field strength to break down water and make it electrically conductive. Therefore, there is no electric current (that may cause damage to cells) in the capture medium in the device.…”

Cost-Effective Screening of Antimicrobial Performance of Multiple Metal–Organic Frameworks via a Droplet-Based Batch Synthesis Platform

“…Screening usually takes place in finding new medicines and high-efficiency catalysts for improving the existing problems of medical-level and industrial production. − With the continuous development of materials science and biomedicine, diversified nanomaterials and their related composites have been manufactured and applied in the antimicrobial field. − However, the existing antimicrobial materials also have huge differences in actual performance. Recently, metal–organic framework (MOF) materials have received much attention in many fields. − Multiple MOFs and MOF-based composites have recently been used as antimicrobial agents, but the antimicrobial properties of different types of MOF materials are dramatically different, as well as their inhibition ability of different strains. − Thus, low-cost evaluation and screening of MOFs with excellent antimicrobial properties are of great significance for antimicrobial research and practical applications in the future.…”

Ionic liquid gel microspheres as an emerging platform for constructing liquid compartment microreactors

“…7 In recent years, microreactors constructed using micro/ nanomaterials are mainly homogeneous solid or liquid microreactors. [8][9][10][11] Liquid particulation and solid nanocrystallization can increase their specific surface areas, and thus, at present, micro/nano-solid-liquid composites have attracted the attention of many researchers in the field of materials science due to combining the advantages of solids and liquids to achieve a synergistic effect, 12,13 especially as the solid in micro/nano-solid-liquid composite based microreactors can stabilize the form of the microreactors and immobilize functional groups, and the liquid has high enrichment capacity for substances as well as can promote the transfer of substances. In addition, the formed solid-liquid composite interfaces generally have excellent wettability and are favorable for multiphase reactions.…”