Jing Zhang

Highly selective chemistries are required for fabrication and post-cross–linking modification of cell-encapsulating hydrogels used in tissue engineering applications. Isonitrile ligation reactions represent a promising class of bioorthogonal chemistries for engineering hydrogel-based cellular microenvironments. Isonitrile-based hydrogels are stable and cytocompatible, and enable precise chemical functionalization in the presence of live cells.

Abstract

Hydrogels are routinely used as scaffolds to mimic the extracellular matrix for tissue engineering. However, common strategies to covalently cross–link hydrogels employ reaction conditions with potential off-target biological reactivity. The limited number of suitable bioorthogonal chemistries for hydrogel cross–linking restricts how many material properties can be independently addressed to control cell fate. To expand the bioorthogonal toolkit available for hydrogel cross–linking, we identify isonitrile ligations as a promising class of reactions. Isonitriles are compact, stable, selective, and biocompatible moieties that react with chlorooxime (ChO), tetrazine (Tz), and azomethine imine (AMI) functional groups under physiological conditions. We demonstrate that all three ligation reactions can form hydrogels, with isonitrile-ChO ligation exhibiting optimal gelation properties. Synthetic poly(ethylene glycol) (PEG) hydrogels cross–linked by isonitrile-ChO ligation exhibit rapid gelation kinetics, elastic mechanical properties, stability under physiological conditions, and high biocompatibility. By combining ChO-functionalized multi-arm PEGs with isonitrile-functionalized engineered elastin-like proteins (ELPs), we demonstrate simultaneous control over network connectivity and adhesive ligand presentation, which in turn regulate cell spreading. These hydrogels enable the long-term culture of numerous human cell types relevant to regenerative medicine. Furthermore, we demonstrate that isonitrile-ChO ligation is orthogonal to common azide-alkyne cycloaddition, enabling independent, bioorthogonal functionalization of hydrogels containing live cells.

Breakthrough NIR emissions at 986 and 1540 nm are achieved via energy funnel and quantum cutting in Yb³⁺/Er³⁺-doped CsPbBr₃: PEACl quasi-2D perovskites. Atomic TEM shows Yb³⁺-Pb²⁺ substitution stabilizes lattices, PE modulation enhances phase distribution for PLQY = 170%. Transient absorption analyzes sensitization. NIR LEDs exhibit EQEs up to 9.32% and 1.96% at 986 and 1540 nm, respectively.

Abstract

Quasi-two-dimensional (quasi-2D) perovskites exhibit efficient visible-light emission, but have remained challenging for near-infrared (NIR) electroluminescence. Here, a breakthrough is reported in achieving NIR emissions at 986 and 1540 nm through quantum cutting in ytterbium/erbium (Yb³⁺/Er³⁺)-doped quasi-2D perovskite films. Atomic-scale transmission electron microscopy reveals that Yb³⁺ ions substitute Pb²⁺ sites, establishing robust halide coordination that stabilizes the lattice and enables efficient energy transfer. The synergistic combination of Yb³⁺ doping and phosphatidylethanolamine (PE) modulates perovskite domain phase distribution, driving the photoluminescence quantum yield (PLQY) to an exceptional 170%—a notable enhancement for NIR emitters. Transient absorption spectroscopy uncovers a cascaded energy transfer mechanism: photoexcited carriers in low-n-phases funnel into the n = ∞ phase, enabling sequential energy transfer to Yb³⁺ ions and subsequent NIR emission. NIR light-emitting diodes are fabricated with record-high external quantum efficiencies (EQEs) of 9.32% at 986 nm and 1.96% at 1540 nm. This work provides atomic-scale insights into lanthanide ion integration in perovskites and establishes a universal strategy for quantum-cutting sensitization in optoelectronic materials, paving the way for next-generation NIR optoelectronic technologies.

This study presents a novel class of luminescent nanothermometer, chromatic nanoswitcher (ChNS), designed for precise intracellular temperature monitoring. The phase transition-related optical properties of ChNS enable a high thermal sensitivity in the physical temperature range with a thermal response independent by fluctuations of other physiological factors like pH, viscosity or ionic strength. ChNS is successfully applied to achieve intracellular thermal monitoring of cellular metabolism.

Abstract

Accurate sensing of intracellular temperature is crucial for understanding and monitoring cell metabolism, serving as an initial step toward diagnosing conditions such as mitochondria-related diseases. However, thermal monitoring of cell metabolism is challenging due to the minimal temperature variations caused by intracellular metabolic activity (typically ≈1 °C) and by the risk of crosstalk in intracellular sensors. A novel type of intracellular thermal sensor is presented, based on silica nanocapsules filled with a thermo-responsive fluorescent medium. This medium undergoes a reversible phase transition from solid to liquid at temperatures ≈37 °C, inducing a chromatic switch that facilitates remote thermal sensing. The chromatic switchers exhibit a thermal sensitivity of ≈13% °C⁻¹ at 37 °C, one of the highest reported for intracellular thermal sensing. Notably, the thermal response is unaffected by external factors such as pH, ionic strength, and viscosity. Moreover, it is confirmed that the response of the sensors is not affected by the cellular activity, underscoring their reliability for cytoplasmic temperature measurements. The potential of these sensors is demonstrated by measuring intracellular heating during the metabolic switch from mitochondrial to glycolytic activity, showcasing their potential for real-time, precise thermal monitoring (<1 °C) of cell metabolism.

Ultrathin, skin-conformal sensor arrays based on Ag flake–decorated PEDOT:PSS composites enable high-resolution, spatially resolved temperature mapping across human skin. The optimized composite formulation exhibits high thermal sensitivity (−2.02% °C⁻¹), mechanical durability, and reliable environmental stability, offering a promising platform for wearable healthcare electronics and future multimodal physiological monitoring.

Abstract

Rapid and spatial temperature measurement on the skin is essential for detecting localized physiological anomalies, such as inflammation or circulatory issues, while providing insights into thermoregulation. Skin-conformal temperature sensors, with ultra-flexible designs, enable precise and comfortable measurements, supporting real-time monitoring, early diagnosis, and effective intervention. However, achieving rapid and spatial skin-conformal temperature sensor arrays that simultaneously maintain high sensitivity under extreme mechanical stresses remains a significant challenge. This work introduces a skin-conformal temperature sensor array based on a composite of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) and Ag flakes, fabricated on a 2-µm-thick parylene-C substrate. A simple mixing process achieves uniform dispersion of Ag flakes, enhancing electrical conductivity to 2.04 kS cm⁻¹. The sensor demonstrates a temperature coefficient of resistance of −2.02%/°C (30–50 °C), a resolution of 0.5 °C, and a rapid response time under 0.41 s per 5 °C change. It endures over 1000 cycles of 200% strain and performs reliably under 3 µm bending radii. Demonstrating high-resolution sensitivity and spatial temperature mapping through letter pattern recognition, the sensor shows promise for applications in body temperature monitoring, thermal imaging, and early diagnosis of temperature-related health conditions.

Surprisingly, a cell can bind to itself to make a self-adhesion, which engineered here to improve how cells attach to biomaterials. Nanoprinting are used to make 3D structures smaller than cells–called Self-Adhesion-Tunnels (SATs)–around which cells can wrap and bind to themselves. These self-adhesions improve cell attachment stability and offer a new approach for biomaterial design.

Abstract

A cell can bind to itself and form a self-adhesion that can be engineered and harnessed as a new way to adhere cells to engineered materials–a key challenge for biomaterials are demonstrated. Here, a 3D structure smaller is developed than a single cell, that a Self-Adhesion-Tunnel (SAT) is called, that causes cells to wrap around it and bind to themselves. This process is driven through the cadherin proteins that regulate cell-cell adhesion, and it is shown that many of the key elements of a normal cell-cell adhesion are found in self-adhesions. Size and shape of the SAT determine the efficiency of self-adhesion formation, and >90% efficient formation of self-adhesions are observed in both kidney and skin cells per SAT. Self-adhesions can persist for at least 24 hrs and act to stabilize the cell-material interface and reduce migration. Overall, this ability to co-opt the native cell-cell adhesion machinery in cells and use it as an attachment strategy can provide new approaches for soft-tissue implant integration and tissue engineering scaffolds where stable tissue-material interfaces are critical.

Nature Communications, Published online: 23 May 2025; doi:10.1038/s41467-025-60050-7

Controlling phase transitions in MoOx semiconductors is challenging. Here, the authors develop a lab-on-device system to modulate proton intercalation, achieving conductance modulation and enabling electrochemical memory and neural network applications.

Nature Physics, Published online: 22 May 2025; doi:10.1038/s41567-025-02920-x

Solid-state quantum devices can suffer from decoherence caused by fluctuating electron spins in the surrounding material. Operating in a regime where the electron spins become magnetically ordered produces substantially longer coherence times.

Underwater Metasurface

In article number 2420229, Yu-Gui Peng, Teng Ma, Hai-Rong Zheng, Xue-Feng Zhu, and co-workers present a general approach for designing an ultrathin ultrasonic metasurface with a high pixel array to achieve various high-resolution manifold holograms underwater in the far field, greatly enhancing the information capacity encoded in a single metasurface. Multifunctional meta-devices based on binary amplitude modulation, which can project holographic acoustic fields at different positions or frequencies on demand, provide more opportunities for exploring practical applications of ultrasonic metasurfaces in biomedical engineering.

By placing WSe₂/InSe vdWH onto the specifically designed gold nanoarray metastructure, interlayer exciton emission enhancement factor (EF) of up to 52 times and an anisotropic ratio (AR) of 23% are achieved simultaneously, which arise from the coupling of plasmonic resonance modes with the excitation field in the visible and aligns with the excitonic emission in the near-infrared at 1120 nm.

Abstract

2D van der Waals heterostructures (vdWH) serve as ideal platforms for studying interlayer excitons (IX) and developing excitonic devices. Typically, IX exhibit in-plane isotropy and weak oscillator strengths, limiting their application in high-performance and polarization-sensitive optoelectronics. In this work, through the coupling of plasmonic resonances to multilayer WSe₂/InSe vdWH, both anisotropy and enhancement of IX emissions are achieved thanks to the specifically designed metastructure, which couples plasmonic resonance modes with the excitation field in the visible and aligns with the excitonic emission in the near-infrared (NIR). By harnessing the significantly enhanced electromagnetic field generated by the anisotropic plasmonic resonance, a remarkable 52-fold increase is achieved in IX emission intensity, accompanied by an anisotropic ratio of 23%. Furthermore, by utilizing the polarization-sensitive and enhanced interlayer absorption, a NIR WSe₂/InSe photodetector is fabricated on the metastructure, achieving a linear polarization ratio of 5.2 along with an optimal photoresponsivity of 1.85 mA W⁻¹ at 1120 nm, one order of magnitude higher than the pristine WSe₂/InSe photodetector. This work provides a universal approach for introducing anisotropy into IX, while simultaneously enhancing the IX emission and interlayer absorption in 2D vdWH.

Contact electrification between cell culture vessels with different materials induces surface charge accumulation, generating electrostatic fields that influence cell behaviour. This study examines charge generation and its effects on cell growth and metabolism. The findings emphasize the importance of considering electrostatic effects in biotechnology research to optimize cell culture conditions.

Abstract

Since cells are extraordinarily sensitive, even slight variables can critically affect the reproducibility of cell culture outcomes. Therefore, despite significant investments of time and resources to mitigate the impact of unnecessary external factors such as biological and chemical impurities, inconsistencies in cell culture results still pose unavoidable errors, even under identical conditions. In this study, contact-induced electrostatic charges as an overlooked external factor that could influence cell culture outcomes, are proposed first. These experimental findings, which are derived from measuring the electrical output, surface potential, and electrostatic fields caused by these charges, confirm that substantial electrostatic charges can be generated and accumulated on the surface of cell culture vessels through contact with other materials. Subsequently, the influence of generated charges on cells by cultivating them on specially fabricated cell culture vessels, which can provide various electrostatic environments, is examined. The results clearly demonstrate that excessive electrostatic charges suppress cell proliferation and metabolic activity, while neutralizing these charges significantly enhances both cellular proliferation and adhesion. These results reveal that the quantity of electrostatic charges significantly affects cell proliferation and adhesion. Furthermore, the management of electrostatic charges could enhance cell growth and reduce errors in cell culture outcomes, thereby improving both cost and time efficiency.

This study demonstrates 2PP-printed microstructures combined with regions of unpolymerized resin, which can be subsequently UV-polymerized via 1PP. This approach enables complex refractive index distributions within a single material. Two types of photonic crystal fibers are fabricated, showing different properties and responses to UV-induced refractive index changes, including transitions between index-guiding and photonic bandgap guiding.

Abstract

A difference in refractive indices between polymers produced by two-photon polymerization (2PP) and one-photon polymerization (1PP) opens up a possibility for fabricating multi-refractive-index nanostructures. It significantly expands the design capabilities of 3D nanoprinting technologies based on 2PP-enabled direct laser writing (DLW). One key application is waveguide design, where the refractive index contrast between the core and the cladding materials determines light propagation properties. This study demonstrates the combination of 2PP and 1PP to fabricate photonic crystal fiber (PCF) segments, creating structures with a complex 3D refractive index distribution. Refractive index properties of commercially available IP-Dip and IP-S photoresins, commonly used in 2PP nanoprinting, are analyzed based on supplier data and previous research. Using these findings, PCF structures are designed to facilitate light propagation through either index-guiding (IG) or photonic bandgap (PBG) guiding mechanisms. The fabrication process is carried out using 2PP, exploiting the refractive index contrast between polymerized and unpolymerized resin regions. Subsequently, controlled UV exposure induces refractive index modifications in previously unpolymerized regions, enabling transitions between IG-to-PBG, PBG-to-IG, and IG-to-no guiding. This approach facilitates the fabrication of waveguides with tailored propagation properties, and by adjusting the PCF's transverse geometry and refractive index contrast, specific mode distributions can be achieved.

This review comprehensively summarizes the synthesis of large-area 2D transition metal dichalcogenides via chemical vapor deposition, detailing growth strategies, single-crystal growth mechanisms and scalable transfer methods for large-area transition metal dichalcogenides. It further highlights their applications in logic circuits, optoelectronics and displays.

Abstract

Transition metal dichalcogenides (TMDCs), with excellent merits such as atomic-layer thickness, tunable bandgaps, high carrier mobility and good compatibility with traditional semiconductor processes, are one of the promising candidates for the next generation of semiconductor channel materials, expected to overcome the physical limitations of conventional silicon-based materials and extend Moore's Law. Recognizing the vast potential of TMDCs in revolutionizing semiconductor technology, researchers are intensively exploring various preparation techniques for industrialization. Among these, chemical vapor deposition (CVD) has emerged as a frontrunner to synthesize high-quality and large-area TMDCs film. In this review, the focus is on the current progress in the growth of large-area TMDCs films via the CVD method. Insights into the preparation of large-area TMDCs, including growth strategies and growth mechanisms, are first presented. Second, the transfer approaches are summarized, covering wet and dry transfer methods for the large-area TMDCs. Third, their applications in logic circuits, optoelectronics and displays are explored. In the end, a summary and outlook are provided in terms of the current challenges and future research directions, inspiring further research and development efforts in this area.

Mxene-Based Neural Electrodes

In article number 2424236, Zhanhong Du and co-workers present a two-step spinning process with strain control to fabricate MXene/PEDOT-PSS neural electrodes. These electrodes exhibit outstanding electrical performance for neural recording and stimulation, enabling surface and in vivo recording, effective deep brain stimulation, and compatibility with magnetic resonance imaging.

Spatiotemporal thermoreflectance microscopy locally probes lateral thermal transport in ultrathin colloidal nanocrystal supercrystals. In stark contrast to typical materials, the thermal diffusivity is nearly constant with decreasing thickness from bulk to few-layers and remarkably is enhanced approaching the monolayer. This inverted thermal size effect suggests that ballistic heat carriers within the interstitial ligand play a role not previously revealed.

Abstract

Understanding the thermal properties of nanocrystal solids is important for their implementation. However, probing the intrinsic properties of monolayer to few-layer supercrystals where non-diffusive effects can emerge has remained elusive. Here, spatiotemporally resolved thermoreflectance microscopy and correlative atomic force microscopy are used to locally access lateral thermal transport in gold nanocrystal supercrystals with long polymer ligands from the monolayer up to eight layers. In contrast to the thermal size effect of typical thin film materials, it is demonstrated that above a few supercrystal layers the thermal diffusivity is nearly constant with increasing thickness. Notably, the mono-to-few layer range moreover experiences an inverted thickness dependence wherein the lateral thermal diffusivity increases when approaching the monolayer to a value 30–60% larger than the bulk. Simulations of quasi-ballistic thermal transport successfully model the experimental trend, indicating the need to account for the phonon mean free path in the ligand matrix and the geometry of scattering interfaces. Phonons responsible for heat transport within the nanocrystalline composite have mean free paths shorter than the thickness of single supercrystal layers. This leads to behavior distinct from typical thickness-dependent phonon–boundary scattering. These unusual behaviors present important considerations and opportunities for thermal management in applications of nanocrystal solids.

This review systematically examines the nanomechanical mechanisms of mussel-inspired molecular interactions, primarily investigated by direct force measurement techniques such as surface forces apparatus and atomic force microscopy. The macroscopic adhesive and self-healing performances of mussel-inspired functional materials, including coacervates, coatings, and hydrogels, are correlated with the underlying reversible and dynamic molecular interactions.

Abstract

The exceptional underwater adhesion and self-healing capabilities of mussels have fascinated researchers for over two decades. Extensive studies have shown that these remarkable properties arise from a series of reversible and dynamic molecular interactions involving mussel foot proteins. Inspired by these molecular interaction strategies, numerous functional materials exhibiting strong underwater adhesion and self-healing performance have been successfully developed. This review systematically explores the nanomechanical mechanisms of mussel-inspired molecular interactions, mainly revealed by direct force measurement techniques such as surface forces apparatus and atomic force microscopy. The development of functional materials, including coacervates, coatings, and hydrogels, with underwater adhesion and self-healing properties, is then summarized. Furthermore, the macroscopic material performances are correlated with the underlying molecular mechanisms, providing valuable insights for the rational design of next-generation mussel-inspired functional materials with enhanced underwater adhesion and self-healing properties.

In this work, an In³⁺ alloyed antimony halide hybrid (C₄H₁₂N₂)₅[(SbCl₅)₂(InCl₆)Cl₄] exhibiting high stability, large stokes shift, and near unity photoluminescence quantum yield is successfully prepared, which is an excellent yellow phosphor for applications such as WLED lighting and anti-counterfeiting.

Abstract

While metal doping strategies have proven effective in regulating the bandgap and enhancing the photophysical properties of hybrid metal halides, site-specific atom alloying by mixing metals of different elements offers a new route for material modification. Here an antimony halide hybrid material with the formula of (C₄H₁₂N₂)₅[(SbCl₅)₂(SbCl₆)Cl₄] (Py-SbCl) is shown with crystallographically independent alternating square pyramidal [SbCl₅] and octahedral [SbCl₆] sites sandwiched by organic layers. Interestingly, the octahedral site of the [SbCl₆] can be fully replaced by the In³⁺ ions, forming the alloyed compound (C₄H₁₂N₂)₅[(SbCl₅)₂(InCl₆)Cl₄] (Py-SbInCl). More importantly, the latter shows a near-unity photoluminescence quantum yield of 97%, which is ≈7 times of enhancement compared to the pristine Py-SbCl compound. This is mainly due to the much-enhanced Young's modulus, higher radiative decay rates and longer electron transient rates, presumably stemming from shorter In─Cl bond distances and higher dipole moments, as revealed by a cocktail study of X-ray single-crystal crystallography, density functional theory, femtosecond transient absorption spectroscopy and so on. In addition, it is shown that Py-SbInCl is an excellent yellow phosphor that can be used for white light-emitting diodes and other applications such as counterfeiting. Therefore, making site-specific alloying compounds may open a new design approach for functional bimetallic hybrid materials.

Nature Communications, Published online: 14 May 2025; doi:10.1038/s41467-025-59600-w

Tunable chiroptical structures are of extensive interest. Here, the authors show designs and experimental implementations of a programmable, scalable chiroptical heterostructure containing twisted aligned carbon nanotubes and phase change materials.

Nature Communications, Published online: 14 May 2025; doi:10.1038/s41467-025-59238-8

The authors present experimental evidence of three-dimensional superinsulation in a nanopatterned slab of NbTiN. In the electric Meissner state, they find polar nematic order arising from ferroelectric alignment of short electric strings excited by external electromagnetic fields.

The fabrication of patterned transition metal dichalcogenide (TMD)/graphene heterostructures via direct laser writing reveals new interface chemistry and enables efficient, customizable assembly. Selective laser irradiation of functionalized TMD/graphene triggers localized reactions, forming chemically modified interfaces. Experimental and theoretical analyses provide insights into laser-induced interface chemistry, enhancing patterning compatibility and advancing confined two-dimensional (2D)-space chemistry.

Abstract

Connecting two-dimensional (2D) material layers via interface linkers represents a new avenue for fabricating 2D heterostructures. Utilizing light to remotely modulate this interface function allows for seamless assembly and patterning in a single run. Here, an efficient method for fabricating patterned 2D heterostructures using direct laser writing is demonstrated, drawing a conceptual parallel to laser printing. In the approach, functionalized transition metal dichalcogenide (TMD) dispersions serve as inks, graphene as the substrate, and a Raman laser as the patterning tool. Unlike laser printing's electrostatic interactions, the method achieves patterned assembly through covalent bonding between TMDs and graphene. Selective Raman laser irradiation of functionalized TMD/graphene heterostructures triggers localized reactions, forming chemically modified domains exclusively in the laser-irradiated regions, as confirmed by Raman spectroscopy, Kelvin probe force microscopy (KPFM), and time-of-flight secondary ion mass spectrometry (ToF-SIMS). Experimental and theoretical analyses of the interface composition and structure provide new insights into laser-induced chemistry. The work demonstrates the potential for high-throughput assembly of customizable 2D heterostructures, with enhanced compatibility for subsequent patterning through photolabile linkers and photoinduced coupling. Additionally, the results provide deeper insights into chemistry within confined 2D spaces, offering a novel approach to nanoscale heterostructure engineering.

In this work we show that light-responsive adaptive organic matter can store and process information at the matter level, and emulate neuromorphic functionalities such as short term memory, long term memory and visual memory. Besides demonstrating that material dynamics can be exploited for spatio-temporal event detection and motion perception, we show that these adaptive photo-responsive organic systems can be exploited for hardware implementation of physical reservoir computing.

Abstract

Materials able to sense and respond to external stimuli by adapting their internal state to process and store information, represent promising candidates for implementing neuromorphic functionalities and brain-inspired computing paradigms. In this context, neuromorphic systems based on light-responsive materials enable the use of light as information carrier, allowing to emulate basic functions of the human retina. In this work it is demonstrated that optically-induced molecular dynamics in azopolymers can be exploited for neuromorphic-type of data processing in the analog domain and for computing at the matter level (i.e., in materia). Besides showing that azopolymers can be exploited for data storage, it is demonstrated that the adaptiveness of these materials enables the implementation of synaptic functionalities including short-term memory, long-term memory, and visual memory. Results show that azopolymers allow event detection and motion perception, enabling physical implementation of information processing schemes requiring real-time analysis of spatio-temporal inputs. Furthermore, it is shown that light-induced dynamics can be exploited for the in materia implementation of the unconventional computing paradigm denoted as reservoir computing. This work underscores the potential of azopolymers as promising materials for developing adaptive, intelligent photo-responsive systems that mimic some of the complex processing abilities of biological systems.

Rechargeable Deep-Tissue Implantable Devices

Implantable devices typically rely on batteries that require surgical replacement, leading to potential health risks and financial burdens. Ultrasound energy transfer presents a promising wireless alternative, though its efficiency remains a challenge. The proposed dielectric-ferroelectric-boosted ultrasound triboelectric nanogenerator is a thin, flexible, and biocompatible solution that enables efficient and stable power delivery, even in curved configurations. This innovation paves the way for noninvasive, sustainable wireless energy transfer in biomedical applications. More details can be found in article number 2419264 by Sunghoon Hur, Hyun-Cheol Song, and co-workers.

This study introduces a protein-based aqueous photoresist derived from chemically modified silk fibroin that employs an entirely water-based process for achieving high-resolution micropatterning (<1.2 µm) with excellent biocompatibility. The conjugation of biofunctional molecules to the photoresist further allows the efficient and high-throughput fabrication of multiplexed biofunctional micropatterns, with potential applications in biosynthesis, diagnostics, and biosensors.

Abstract

Photolithography is the most widely used micropatterning technique at the micro- and nanoscale in device fabrication. However, traditional photoresists used in photolithography are typically nonaqueous-based toxic substances that require harsh conditions for processing, limiting the development of biofunctional and biocompatible micropatterns. In this study, a protein-based aqueous photoresist derived from chemically modified silk fibroin named SAMA, capable of achieving high-resolution micropatterning (<1.2 µm) while retaining good biocompatibility, is presented. The entire fabrication process, including spin-coating, development, and lift-off, employs solely SAMA and water, eliminating the need for toxic reagents and elevated temperature. Notably, the SAMA photoresist allows covalent conjugation of biofunctional molecules, such as enzymes and nucleic acids, while preserving their bioactivity during micropatterning. This innovative approach enables the high-throughput generation of bioactive micropatterns for various applications such as biosynthesis, diagnostics, and biosensors.

Photolithography

Traditional photoresists used in photolithography are typically toxic, nonaqueous substances that require harsh processing conditions, which limits the development of biofunctional and biocompatible micropatterns. In article number 2411900, Xiaorui Zheng, Chengchen Guo, and colleagues introduce a protein-based aqueous photoresist derived from chemically modified silk fibroin. This photoresist employs an entirely water-based process to achieve high-resolution multiplexed micropatterning with designed functionalities, demonstrating significant potential in biomedical applications.

This document illustrates magnetic steganography. Magnetic graphics, including pixel art and QR codes, are produced using magnetic materials (such as Ni) and obscure behind patterns manufactured using non-magnetic materials (such as Au), which are unveiled through widefield quantum microscopy. Furthermore, manipulating the electron spin of NV with dual micrwave fields enhances imaging speed by a factor of three.

Abstract

Magnetic steganography using wide-field quantum microscopy based on diamond nitrogen-vacancy (NV) centers is experimentally demonstrated. The method offers magnetic imaging capable of revealing concealed information otherwise invisible with conventional optical measurements. For a proof-of-principle demonstration of magnetic steganography, micrometer structures designed as pixel arts, barcodes, and QR codes are fabricated using mixtures of magnetic and non-magnetic materials: Ni and Au. Three different imaging modes based on the changes in frequency, linewidth, and contrast of the NV's electron spin resonance are compared and find that the last mode offers the best quality for reconstructing hidden magnetic images. By simultaneous driving of the NV's qutrit states with two independent microwave fields, the imaging time is expedited by a factor of three. This work shows potential applications of quantum magnetic imaging in the field of image steganography.