Optical nanomaterials have been widely used in anticounterfeiting applications. There have been significant developments powered by recent advances in material science, printing technologies, and the ...availability of smartphone‐based decoding technology. Recent progress in this field is surveyed, including the availability of optical reflection, absorption, scattering, and luminescent nanoparticles. It is demonstrated that advances in the design and synthesis of lanthanide‐doped upconversion nanoparticles will lead to the next generation of anticounterfeiting technologies. Their tunable optical properties and optical responses to a range of external stimuli allow high‐security level information encoding. Challenges in the scale‐up synthesis of nanomaterials, engineering of assessorial devices for smart‐phone‐based decryption, and alignment to the potential markets which will lead to new directions for research, are discussed.
Recent advances in the development of anticounterfeiting technologies are surveyed. It is demonstrated that lanthanide‐doped upconversion nanoparticles hold significant potential for developing next‐generation high‐level anticounterfeiting technologies. This is a result of synthesis scale‐up, their multidimensional optical properties, and design strategies to encrypt information. Engineering compact smartphone‐based decryption devices is a future trend for next‐generation anticounterfeiting technologies.
Multidimensional or multiplex bioanalysis represents a crucial approach to improve diagnostic precision, increase assay throughput and advance fundamental discoveries in analytical industry, life ...science, and nanomedicine. Along this line, bio‐interfacing magnetic particles have been playing an important role. Fully exploiting the properties of magnetic particles is the key to tailoring recent technology development for better translational outcomes. In this mini‐review, typical magneto‐physical dimensions of magnetic particles are introduced. Recent progress of implementing these dimensions with advanced sensor and actuator technologies in multiplex bioanalysis is discussed. Outlooks on potential biomedical applications and challenges are provided.
In article number 20200076, Gungun Lin has summarized typical magneto‐physical dimensions of magnetic particles and discussed recent progress of implementing these dimensions with advanced sensor and actuator technologies for multiplex bioanalysis. The review also identified the challenges and highlighted a few emerging directions of applying magnetic particles for multidimensional and multiscale bioanalysis.
Abstract
Precise design and fabrication of heterogeneous nanostructures will enable nanoscale devices to integrate multiple desirable functionalities. But due to the diffraction limit (~200 nm), the ...optical uniformity and diversity within the heterogeneous functional nanostructures are hardly controlled and characterized. Here, we report a set of heterogeneous nanorods; each optically active section has its unique nonlinear response to donut-shaped illumination, so that one can discern each section with super-resolution. To achieve this, we first realize an approach of highly controlled epitaxial growth and produce a range of heterogeneous structures. Each section along the nanorod structure displays tunable upconversion emissions, in four optical dimensions, including color, lifetime, excitation wavelength, and power dependency. Moreover, we demonstrate a 210 nm single nanorod as an extremely small polychromatic light source for the on-demand generation of RGB photonic emissions. This work benchmarks our ability toward the full control of sub-diffraction-limit optical diversities of single heterogeneous nanoparticles.
Mammary tumor organoids have become a promising in vitro model for drug screening and personalized medicine. However, the dependency on the basement membrane extract (BME) as the growth matrices ...limits their comprehensive application. In this work, mouse mammary tumor organoids are established by encapsulating tumor pieces in non‐adhesive alginate. High‐throughput generation of organoids in alginate microbeads is achieved utilizing microfluidic droplet technology. Tumor pieces within the alginate microbeads developed both luminal‐ and solid‐like structures and displayed a high similarity to the original fresh tumor in cellular phenotypes and lineages. The mechanical forces of the luminal organoids in the alginate capsules are analyzed with the theory of the thick‐wall pressure vessel (TWPV) model. The luminal pressure of the organoids increase with the lumen growth and can reach 2 kPa after two weeks’ culture. Finally, the mammary tumor organoids are treated with doxorubicin and latrunculin A to evaluate their application as a drug screening platform. It is found that the drug response is related to the luminal size and pressures of organoids. This high‐throughput culture for mammary tumor organoids may present a promising tool for preclinical drug target validation and personalized medicine.
Mammary tumor organoids culture heavily relies on basement membrane extract hydrogels. Herein, non‐adhesive alginate is found to be a good candidate for the culture of mouse mammary tumor organoids. Alginate microbeads generated by microfluidic droplet technique enhance the organoid's yield and are further used for luminal mechanics and high‐throughput drug screening.
Topological magnetic states, such as chiral skyrmions, are of great scientific interest and show huge potential for novel spintronics applications, provided their topological charges can be fully ...controlled. So far skyrmionic textures have been observed in noncentrosymmetric crystalline materials with low symmetry and at low temperatures. We propose theoretically and demonstrate experimentally the design of spin textures with topological charge densities that can be tailored at ambient temperatures. Tuning the interlayer coupling in vertically stacked nanopatterned magnetic heterostructures, such as a model system of a Co/Pd multilayer coupled to Permalloy, the in-plane non-collinear spin texture of one layer can be imprinted into the out-of-plane magnetised material. We observe distinct spin textures, e.g. vortices, magnetic swirls with tunable opening angle, donut states and skyrmion core configurations. We show that applying a small magnetic field, a reliable switching between topologically distinct textures can be achieved at remanence.
We report a magnetofluidic device with integrated strong ferromagnetically-coupled and hysteresis-free spin valve sensors for dynamic monitoring of ferrofluid droplets in microfluidics. The strong ...ferromagnetic coupling between the free layer and the pinned layer of spin valve sensors is achieved by reducing the spacer thickness, while the hysteresis of the free layer is eliminated by the interplay between shape anisotropy and the strength of coupling. The increased ferromagnetic coupling field up to the remarkable 70 Oe, which is five-times larger than conventional solutions, brings key advantages for dynamic sensing, e.g., a larger biasing field giving rise to larger detection signals, facilitating the operation of devices without saturation of the sensors. Studies on the fundamental effects of an external magnetic field on the evolution of the shape of droplets, as enabled by the non-visual monitoring capability of the device, provides crucial information for future development of a magnetofluidic device for multiplexed assays.
Upconversion nanoparticles are a class of luminescent materials that convert longer-wavelength near-infrared photons into visible and ultraviolet emissions. They can respond to various external ...stimuli, which underpins many opportunities for developing the next generation of sensing technologies. In this perspective, the unique stimuli-responsive properties of upconverting nanoparticles are introduced, and their recent implementations in sensing are summarized. Promising material development strategies for enhancing the key sensing merits, including intrinsic sensitivity, biocompatibility and modality, are identified and discussed. The outlooks on future technological developments, novel sensing concepts, and applications of nanoscale upconversion sensors are provided.
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