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Whispering gallery mode (WGM) laser sensors, utilizing the interaction between the in-plane evanescent field and the surface vicinity, provide enhanced sensitivity in label-free sensing for bioanalysis and disease screening. However, the unavoidably excited spiral modes resulting from the weak axial confinement and their sensing potential were overlooked. In this study, a microfluidic biosensor using the localized conical modes of an active resonator based on the thin-walled capillaries was developed, demonstrating ultrasensitive refractive index and biomolecule detection capabilities. This sensor provides nonspecific detection of bovine serum albumin (BSA) and specific detection of Carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5) with ultra-low detection limits, large sensing range, rapid response, and a cost-effective design, making it a promising candidate for industrial-scale production. The theoretical detection limit for CEACAM5 is as low as 0.38ag/mL (5zM), and the sensitivity in the linear region reaches 0.25nm/(ag/mL). These results are approximately an order of magnitude higher in sensitivity than currently reported active WGM biosensors, demonstrating

Microfluidic droplet screens serve as an innovative platform for high-throughput biotechnology, enabling significant advancements in discovery, product optimization, and analysis. This review sheds light on the emerging trend of interaction assays in microfluidic droplets, underscoring the unique suitability of droplets for these applications. Encompassing a diverse range of biological entities such as antibodies, enzymes, DNA, RNA, various microbial and mammalian cell types, drugs, and other molecules, these assays demonstrate their versatility and scope. Recent methodological breakthroughs have escalated these screens to novel scales of bioanalysis and biotechnological product design. Moreover, we highlight pioneering advancements that extend droplet-based screens into new domains: cargo delivery within human bodies, application of synthetic gene circuits in natural environments, 3D-printing, and the development of droplet structures responsive to environmental signals. The potential of this field is profound and only set to increase.

When a micron-sized magnetizable particle is introduced into a suspension of nanosized magnetic particles, the nanoparticles accumulate around the microparticle and form thick anisotropic clouds extended in the direction of the applied magnetic field. This phenomenon promotes colloidal stabilization of bimodal magnetic suspensions and allows efficient magnetic separation of nanoparticles used in bioanalysis and water purification. In the present work, size and shape of nanoparticle clouds under the simultaneous action of an external uniform magnetic field and the flow have been studied in details. In experiments, dilute suspension of iron oxide nanoclusters (of a mean diameter of 60 nm) was pushed through a thin slit channel with the nickel microspheres (of a mean diameter of 50$μ$m) attached to the channel wall. The behavior of nanocluster clouds was observed in the steady state using an optical microscope. In the presence of strong enough flow, the size of the clouds monotonically decreases with increasing flow speed in both longitudinal and transverse magnetic fields. This is qualitatively explained by enhancement of hydrodynamic forces washing the nanoclusters away from the clo

Compound droplets can be used in substance encapsulation and material compartmentalization to achieve a precise control over the relevant processes in many applications, such as bioanalysis, pharmaceutical manufacturing, and material synthesis. The flow fields in compound droplets directly affect the performance of these applications, but it is challenging to measure them experimentally. In this study, the flow in compound droplets in axisymmetric microchannels is simulated using the Finite Volume Method, and the interface is captured using the Level Set Method with surface tension accounted for via the Ghost Fluid Method. The combination of the Level Set Method and the Ghost Fluid Method reduces spurious currents that are produced unphysically near the interface, and achieves a precise simulation of the complex flow field within compound droplets. The shape of compound droplets, the vortical patterns, the velocity fields, and the eccentricity are investigated and the effects of the key dimensionless parameters, including the size of the compound droplet, the size of the core droplet, the capillary number, and the viscosity ratio, are analyzed. The flow structures in multi-layered

Ford dealers were told about the new Escape-sized model; one of them spilled the beans

Application of Microelectronic to bioanalysis is an emerging field which holds great promise. From the standpoint of electronic and system design, biochips imply a radical change of perspective, since new, completely different constraints emerge while other usual constraints can be relaxed. While electronic parts of the system can rely on the usual established design-flow, fluidic and packaging design, calls for a new approach which relies significantly on experiments. We hereby make some general considerations based on our experience in the development of biochips for cell analysis.

Atomically thin semiconductors could enable dramatically smaller and more efficient chips, but a stubborn problem at the boundary between materials has limited their performance。 Researchers have now engineered that atomic interface to protect electron flow while still allowing extremely thin insulating layers。 The resulting transistors delivered a

Researchers have found a way to build much larger “twisted” oxide materials while precisely controlling how their atomic layers line up。 Because these materials can be made over large areas and transferred onto different surfaces, the technique could help turn twistronics from a laboratory curiosity into a practical platform for next-generation ele

Ultrafast X-rays revealed how a molecule converts absorbed light into motion in just trillionths of a second。 Individual atoms recorded different stages of the process, opening a powerful new window into light-driven chemistry

Depending on the model, you might have hundreds to choose from—or just one

Device-bound session credentials thwart an increasingly common form of account takeover

Scientists traced a mysterious surge of low-energy gamma rays from zinc-70 to magnetic changes occurring inside its nucleus。 The breakthrough could improve models of how stars, supernovae, and neutron star mergers create heavy elements

The solar wind may be stripping away Mars’ atmosphere by creating giant rolling waves along its outer edge。 Data from MAVEN and Tianwen-1 show that these waves form plasma clouds that carry atmospheric particles into space。 The process is concentrated on one side of Mars and may have played a major role in drying out the once potentially habitable

But will Gemini's surge survive slowing model releases

A rare meteorite that crashed through a New Jersey roof contains evidence of ancient salty fluids, organic compounds, and amino acids from a primitive asteroid。 Its pristine chemistry could offer new clues about how space rocks helped supply early Earth with some of the ingredients needed for life

FDA report reveals where Taylor Farms sent its lettuce—and it raises questions

Hidden moon ice may reveal itself through the way it bends and reflects vibrations from moonquakes。 The technique could help astronauts locate vital water supplies and uncover clues about the origins of Earth’s oceans

A new chemical process can transform three of the most common plastics into high-purity hydrogen without sorting them first。 The technique operates at much lower temperatures than traditional gasification and captures most of the plastic’s carbon in solid or liquid forms instead of releasing it as carbon dioxide