[Advances in artificial cells based on microfluidic chips].

One of the main goals of synthetic biology is to build artificial cells in a bottom-up manner, which not only facilitates the deep understanding of the origin of life and cell function but also plays a critical role in the research fields such as the development of artificial cell chassis, tissue models, engineering drug delivery systems, and drug screening tools. However, achieving this goal is extremely challenging. The complexity of cell structures and the miniaturization and diversity of basic modules pose high requirements for the construction methods.

Synthesis of cobalt phosphide hybrid for simultaneous electrochemical detection of ascorbic acid, dopamine, and uric acid.

Ascorbic acid (AA), dopamine (DA), and uric acid (UA) are important biomarkers for the clinical screening of diseases. However, the simultaneous determination of these three analytes is still challenging. Herein, we report a facile metal-organic framework (MOF)-derived method to synthesize a cobalt phosphide (CoP) hybrid for the simultaneous electrochemical detection of AA, DA and UA.

Microarray Chip and Method for Simultaneous and Highly Consistent Electroporation of Multiple Cells of Different Sizes.

Cell electroporation is an important cell manipulation technology to artificially transfer specific extracellular components into cells. However, the consistency of substance transport during the electroporation process is still an issue due to the wide size distribution of the natural cells. In this study, a cell electroporation microfluidic chip based on a microtrap array is proposed.

Studying the roles of salt ions in the pore initiation and closure stages in the biomembrane electroporation.

Electroporation shows great potential in biology and biomedical applications. However, there is still a lack of reliable protocol for cell electroporation to achieve a high perforation efficiency due to the unclear influence mechanism of various factors, especially the salt ions in buffer solution. The tiny membrane structure of a cell and the electroporation scale make it difficult to monitor the electroporation process.

Trapping and releasing of single microparticles and cells in a microfluidic chip.

A microfluidic device was designed and fabricated to capture single microparticles and cells by using hydrodynamic force and selectively release the microparticles and cells of interest via negative dielectrophoresis by activating selected individual microelectrodes. The trap microstructure was optimized based on numerical simulation of the electric field as well as the flow field. The capture and selective release functions of the device were verified by multi-types microparticles with different diameters and K562 cells.

Applications of Microfluidics in Liquid Crystal-Based Biosensors.

Liquid crystals (LCs) with stimuli-responsive configuration transition and optical anisotropic properties have attracted enormous interest in the development of simple and label-free biosensors. The combination of microfluidics and the LCs offers great advantages over traditional LC-based biosensors including small sample consumption, fast analysis and low cost. Moreover, microfluidic techniques provide a promising tool to fabricate uniform and reproducible LC-based sensing platforms.

Microsphere-Based Microfluidic Device for Plasma Separation and Potential Biochemistry Analysis Applications.

The development of a simple, portable, and cost-effective plasma separation platform for blood biochemical analysis is of great interest in clinical diagnostics. We represent a plasma separation microfluidic device using microspheres with different sizes as the separation barrier. This plasma separation device, with 18 capillary microchannels, can extract about 3 μL of plasma from a 50 μL blood sample in about 55 min.

A Continuous Cell Separation and Collection Approach on a Microfilter and Negative Dielectrophoresis Combined Chip.

Cell separation plays an important role in the fields of analytical chemistry and biomedicine. To solve the blockage problem and improve the separation throughput in the traditional microstructure filtration-based separation approach, a continuous cell separation and collection approach via micropost array railing on a microfilter and negative dielectrophoresis combined chip is proposed. By tilting the micropost array at a certain angle, microparticles or cells enter the collection area under micropost array railing.

Deterministic Lateral Displacement-Based Separation of Magnetic Beads and Its Applications of Antibody Recognition.

This work presents a magnetic-driven deterministic lateral displacement (m-DLD) microfluidic device. A permanent magnet located at the outlet of the microchannel was used to generate the driving force. Two stages of mirrored round micropillar array were designed for the separation of magnetic beads with three different sizes in turn.

Multi-channel surface plasmon resonance biosensor using prism-based wavelength interrogation.

A portable multi-channel surface plasmon resonance (SPR) biosensor device using prism-based wavelength interrogation is presented. LEDs were adopted as a simple and inexpensive light source, providing a stable spectrum bandwidth for the SPR system. The parallel light was obtained by a collimated unit and illuminated on the sensing chip at a specific angle.

An ultra-low frictional interface combining FDTS SAMs with molybdenum disulfide.

Interfacial friction is of crucial importance to ensure the friction-reducing and anti-wear properties of mechanical microstructures in micro/nanoelectromechanical systems (MEMS/NEMS). An ultra-low frictional interface combining hydrophobic 1H,1H,2H,2H-perfluorodecyltrichlorosilane (FDTS) self-assembled monolayers (SAMs) coated on an AFM tip with mechanically exfoliated molybdenum disulfide (MoS) nanosheets deposited on a planar Si/SiO substrate was achieved. The FDTS SAMs/MoS interface between the FDTS SAMs and the MoS nanosheets exhibits an ultra-low friction force that is independent of the relative humidity.

Liquid Crystal Droplet-Embedded Biopolymer Hydrogel Sheets for Biosensor Applications.

The development of simple, portable, and low-cost biosensing platforms is of great interest in the clinical diagnosis of disease. Here, we report liquid crystal (LC) droplet-embedded chitosan (CHI) hydrogel films formed by the Ag(+) ion-triggered fast gelation of the CHI/surfactant complex-stabilized LC emulsion which is cast on substrates. The small sheets cut from the LC droplet-embedded hydrogel films combine the advantages of both hydrogels and LC droplets, offering a portable and label-free sensing platform for the real-time detection of bile acids in a small amount of solution.

Design of β-CD-surfactant complex-coated liquid crystal droplets for the detection of cholic acid via competitive host-guest recognition.

β-CD-C14TAB complex-coated 5CB droplets are designed by the adsorption of β-CD-C14TAB complexes at the 5CB/aqueous interface. We show that the 5CB droplets can be used as an optical probe for the selective detection of cholic acid in aqueous solution containing uric acid and urea via competitive host-guest recognition.

Protein-induced configuration transitions of polyelectrolyte-modified liquid crystal droplets.

Liquid crystal (LC) droplets dispersed in aqueous solution have emerged as an optical probe for sensing the adsorption and interaction of biological species at the LC/aqueous interface. In this paper, we modify the surface of 4-n-pentyl-4'-cyanobiphenyl (5CB) LC droplets by the adsorption of positively charged poly(diallyldimethylammonium chloride) (PDADMAC) and poly(ethylenimine) (PEI) with different molecular weights at the 5CB/water interface. The PDADMAC and PEI-modified 5CB droplets show a radial director configuration in aqueous solution with salt concentrations above 150 mM.