A dynamic assembly-induced emissive system for advanced information encryption with time-dependent security

An ultrawide-range photochromic molecular fluorescence emitter

Photocontrollable luminescent molecular switches capable of changing emitting color have been regarded as the ideal integration between intelligent and luminescent materials. A remaining challenge is to combine good luminescence properties with wide range of wavelength transformation, especially when confined in a single molecular system that forms well-defined nanostructures. Here, we report a π-expanded photochromic molecular photoswitch, which allows for the comprehensive achievements including wide emission wavelength variation (240 nm wide, 400-640 nm), high photoisomerization extent (95%), and pure emission color (<100 nm of full width at half maximum). We take the advantageous mechanism of modulating self-assembly and intramolecular charge transfer in the synthesis and construction, and further realize the full color emission by simple photocontrol. Based on this, both photoactivated anti-counterfeiting function and self-erasing photowriting films are achieved of fluorescence. This work will provide insight into the design of intelligent optical materials.

Light-Driven, Dynamic Assembly of Micron-To-Centimeter Parts, Micromachines and Microbot Swarms

This work describes light-driven assembly of dynamic formations and functional particle swarms controlled by appropriately programmed light patterns. The system capitalizes on the use of a fluidic bed whose low thermal conductivity assures that light-generated heat remains "localized" and sets strong convective flows in the immediate vicinity of the particles being irradiated. In this way, even low-power laser light or light from a desktop slide projector can be used to organize dynamic formations of objects spanning four orders of magnitude in size (from microns to centimeters) and over nine orders of magnitude in terms of mass. These dynamic assemblies include open-lattice structures with individual particles performing intricate translational and/or rotational motions, density-gradient particle arrays, nested architectures of mechanical components (e.g., planetary gears), or swarms of light-actuated microbots controlling assembly of other objects.

Assembly-Induced Dynamic Structural Color in a Host-Guest System for Time-Dependent Anticounterfeiting and Double-Lock Encryption

Manipulation of periodic micro/nanostructures in polymer film is of great importance for academics and industrial applications in anticounterfeiting. However, with the increasing demand on information security, materials with time-dependent features are urgently required, especially the material where the same information can appear more than once on the time scale. Here, one concise strategy to realize time-dependent anticounterfeiting and "double-lock" information encryption based on a host-guest system is proposed, with one photoresponsive azopolymer as the host and one liquid-crystalline molecule as the guest. The system exhibits a tunable mass transport in pre-designed periodic micro/nanostructures by tailoring the process of cis-to-trans recovery of azo groups and assembly of mesogenic trans-isomers, resulting in a dynamic structural color in film. Taking advantage of this extraordinary feature, time-dependent dynamic anticounterfeiting has been achieved. More importantly, the time of each state's appearance in the whole process can be modulated by changing the host-guest ratio. Combining the manipulatable process of mass transport with the unique decoding method, the stored information in film can be decrypted correctly. This work provides an unprecedented dynamic approach for advanced anticounterfeiting technology with a higher level of security and high-end applications in information encryption.

Visual Quantitation of Dopamine-Inspired Fluorescent Adhesion with Orthogonal Phenanthrenequinone Photochemistry

Quantifying adhesion is crucial for understanding adhesion mechanisms and developing advanced dopamine-inspired materials and devices. However, achieving nondestructive and real-time quantitation of adhesion using optical spectra remains challenging. Here, we present a dopamine-inspired orthogonal phenanthrenequinone photochemistry strategy for the one-step adhesion and real-time visual quantitation of fluorescent spectra. This strategy utilizes phenanthrenequinone-mediated photochemistry to facilitate conjoined network formation in the adhesive through simultaneous photoclick cycloaddition and free-radical polymerization. The resulting hydrogel-like adhesive exhibits good mechanical performance, with a Young's modulus of 300 kPa, a toughness of 750 kJ m-3, and a fracture energy of 4500 J m-2. This adhesive, along with polycyclic aromatic phenanthrenequinones, shows strong adhesion (>100 kPa) and interfacial toughness thresholds (250 J m-2) on diverse surfaces─twice to triple as much as typical dopamine-contained adhesives. Importantly, such an adhesive demonstrates excellent fluorescent performance under UV irradiation, closely correlating with its adhesion strengths. Their fluorescence intensities remain constant after continuous stretching/releasing treatment and even in the dried state. Therefore, this dopamine-inspired orthogonal phenanthrenequinone photochemistry is readily available for real-time and nondestructive visual quantitation of adhesion performance under various conditions. Moreover, the adhesive precursor is chemically ultrastable for more than seven months and achieves adhesion on substrates within seconds upon blue light irradiation. As a proof-of-concept, we leverage the rapid and visual quantitation of adhesion and printability to create fluorescent patterns and structures, showcasing applications in information storage, adhesion prediction, and self-reporting properties. This general and straightforward strategy holds promise for rapidly preparing functional adhesive materials and designing high-performance wearable devices.

Supramolecular assembly activated single-molecule phosphorescence resonance energy transfer for near-infrared targeted cell imaging

Pure organic phosphorescence resonance energy transfer is a research hotspot. Herein, a single-molecule phosphorescence resonance energy transfer system with a large Stokes shift of 367 nm and near-infrared emission is constructed by guest molecule alkyl-bridged methoxy-tetraphenylethylene-phenylpyridines derivative, cucurbit[n]uril (n = 7, 8) and β-cyclodextrin modified hyaluronic acid. The high binding affinity of cucurbituril to guest molecules in various stoichiometric ratios not only regulates the topological morphology of supramolecular assembly but also induces different phosphorescence emissions. Varying from the spherical nanoparticles and nanorods for binary assemblies, three-dimensional nanoplate is obtained by the ternary co-assembly of guest with cucurbit[7]uril/cucurbit[8]uril, accompanying enhanced phosphorescence at 540 nm. Uncommonly, the secondary assembly of β-cyclodextrin modified hyaluronic acid and ternary assembly activates a single intramolecular phosphorescence resonance energy transfer process derived from phenyl pyridines unit to methoxy-tetraphenylethylene function group, enabling a near-infrared delayed fluorescence at 700 nm, which ultimately applied to mitochondrial targeted imaging for cancer cells.

High-Sensitive Spatiotemporal Distribution Imaging of Compression Stresses Based on Time-Evolutional Responsiveness

Mechanoresponsive materials have been studied to visualize and measure stresses in various fields. However, the high-sensitive and spatiotemporal imaging remain a challenging issue. In particular, the time evolutional responsiveness is not easily integrated in mechanoresponsive materials. In the present study, high-sensitive spatiotemporal imaging of weak compression stresses is achieved by time-evolutional controlled diffusion processes using conjugated polymer, capsule, and sponge. Stimuli-responsive polydiacetylene (PDA) is coated inside a sponge. A mechanoresponsive capsule is set on the top face of the sponge. When compression stresses in the range of 6.67-533 kPa are applied to the device, the blue color of PDA is changed to red by the diffusion of the interior liquid containing a guest polymer flowed out of the disrupted capsule. The applied strength (F/N), time (t/s), and impulse (F·t/N s) are visualized and quantified by the red-color intensity. When a guest metal ion is intercalated in the layered structure of PDA to tune the responsivity, the device visualizes the elapsed time (τ/min) after unloading the stresses. PDA, capsule, and sponge play the important roles to achieve the time evolutional responsiveness for the high-sensitive spatiotemporal distribution imaging through the controlled diffusion processes.

Silicon Vacancies Diamond/Silk/PVA Hierarchical Physical Unclonable Functions for Multi-Level Encryption

Physical unclonable functions (PUFs) have emerged as a promising encryption technology, utilizing intrinsic physical identifiers that offer enhanced security and tamper resistance. Multi-level PUFs boost system complexity, thereby improving system reliability and fault tolerance. However, crosstalk-free multi-level PUFs remain a persistent challenge. In this study, a hierarchical PUF system that harnesses the spontaneous phase separation of silk fibroin /PVA blend and the random distribution of silicon-vacancy diamonds within the blend is presented. The thermodynamic instability of phase separation and inherent unpredictability of diamond dispersion gives rise to intricate random patterns at two distinct scales, enabling time-efficient hierarchical authentication for cryptographic keys. These patterns are complementary yet independent, inherently resistant to replication and damage thus affording robust security and reliability to the proposed system. Furthermore, customized authentication algorithms are constructed: visual PUFs authentication utilizes neural network combined structural similarity index measure, while spectral PUFs authentication employs Hamming distance and cross-correlation bit operation. This hierarchical PUF system attains a high recognition rate without interscale crosstalk. Additionally, the coding capacity is exponentially enhanced using M-ary encoding to reinforce multi-level encryption. Hierarchical PUFs hold significant potential for immediate application, offering unprecedented data protection and cryptographic key authentication capabilities.

Multiple photofluorochromic luminogens via catalyst-free alkene oxidative cleavage photoreaction for dynamic 4D codes encryption

Controllable photofluorochromic systems with high contrast and multicolor in both solutions and solid states are ideal candidates for the development of dynamic artificial intelligence. However, it is still challenging to realize multiple photochromism within one single molecule, not to mention good controllability. Herein, we report an aggregation-induced emission luminogen TPE-2MO2NT that undergoes oxidation cleavage upon light irradiation and is accompanied by tunable multicolor emission from orange to blue with time-dependence. The photocleavage mechanism revealed that the self-generation of reactive oxidants driving the catalyst-free oxidative cleavage process. A comprehensive analysis of TPE-2MO2NT and other comparative molecules demonstrates that the TPE-2MO2NT molecular scaffold can be easily modified and extended. Further, the multicolor microenvironmental controllability of TPE-2MO2NT photoreaction within polymer matrices enables the fabrication of dynamic fluorescence images and 4D information codes, providing strategies for advanced controllable information encryption.

An acid-chromic luminescent lanthanide metallogel for time-dependent information encryption and anti-counterfeiting

Luminescent materials with dynamic color transformation demonstrate significant potential in advanced information encryption and anti-counterfeiting. In this study, we designed multi-color luminescent lanthanide metallogels featuring time-dependent color transformation. These materials are based on Förster resonance energy transfer (FRET) platforms, facilitating cascade energy transfer from the ligand 4,4',4''-[1,3,5-benzenetriyltris (carbonylimino)]trisbenzoic acid (H3L) to Tb3+ ions and subsequently to Sulforhodamine 101. The emission color of the gels can be readily adjusted by the introduction of HCl, transitioning from initial green, yellow, light red, and red hues to blue, violet, pink, and deep red, respectively. Importantly, the color change in these gels is time-dependent, controlled by the hydrolysis time of glucono-δ-lactone, which modulates the luminescence intensity of H3L, Tb3+, and Sulforhodamine 101. Exploiting these characteristics, we developed methods for information encryption utilizing 3D color codes and anti-counterfeiting flower patterns. These patterns undergo time-dependent transformations, generating a series of 3D codes and flower patterns that can only be recognized in a predetermined manner. These findings highlight the promising application of lanthanide metallogels in advanced information protection strategies.

Dual-Mode Hydrogels with Structural and Fluorescent Colors toward Multistage Secure Information Encryption

Constructing an anti-counterfeiting material with non-interference dual optical modes is an effective way to improve information security. However, it remains challenging to achieve multistage secure information encryption due to the limited stimulus responsiveness and color tunability of the current dual-mode materials. Herein, a dual-mode hydrogel with both independently tunable structural and fluorescent colors toward multistage information encryption, is reported. In this hydrogel system, the rigid lamellar structure of poly(dodecylglyceryl itaconate) (pDGI) formed by shear flow-induced self-assembly provides the restricted domains wherein monomers undergo polymerization to form a hydrogel network, producing structural color. The introduction of fluorescent monomer 6-acrylamidopicolinate (6APA) as a complexation site provides the possibility of fluorescent color formation. The hydrogel's angle-dependent structural color can be controlled by adjusting the crosslinking density and water content. Additionally, the fluorescence color can be modulated by adjusting the ratio of lanthanide ions. Information of dual-mode can be displayed separately in different channels and synergistically overlayed to read the ultimate message. Thus, a multistage information encryption system based on this hydrogel is devised through the programed decryption process. This strategy holds tremendous potential as a platform for encrypting and safeguarding valuable and authentic information in the field of anti-counterfeiting.

Dynamic Near-Infrared Circularly Polarized Luminescence Encoded by Transient Supramolecular Chiral Assemblies

Circularly polarized luminescence (CPL) is promising for applications in many fields. However, most systems involving CPL are within the visible range; near-infrared (NIR) CPL-active materials, especially those that exhibit high glum values and can be controlled spatially and temporally, are rare. Herein, dynamic NIR-CPL with a glum value of 2.5×10-2 was achieved through supramolecular coassembly and energy-transfer strategies. The chiral assemblies formed by the coassembly between adenosine triphosphate (ATP) and a pyrene derivative exhibited a red CPL signal (glum of 10-3). The further introduction of sulfo-cyanine5 resulted in a energy-transfer process, which not only led to the NIR CPL but also increased the glum value to 10-2. Temporal control of these chiral assemblies was realized by introducing alkaline phosphatase to fabricate a biomimetic enzyme-catalyzed network, allowing the dynamic NIR CPL signal to be turned on. Based on these enzyme-regulated temporally controllable dynamic CPL-active chiral assemblies, a multilevel information encryption system was further developed. This study provides a pioneering example for the construction of dynamic NIR CPL materials with the ability to perform temporal control via the supramolecular assembly strategy, which is expected to aid in the design of supramolecular complex systems that more closely resemble natural biological systems.

Regulation of Fluorescence and Self-assembly of a Salicylaldehyde Azine-Containing Amphiphile by Pillararene

Regulation of fluorescence and self-assembly of a salicylaldehyde azine-containing amphiphile by a water-soluble pillar[5]arene via host-guest recognition in water was realized. The fluorescence and the self-assembled aggregates of the bola-type amphiphile G can be tailored by adding different amounts of water-soluble pillar[5]arene (WP5). In addition, the emission property and self-assembly behavior of G and WP5 are responsive to pH conditions. Furthermore, the fluorescence emission property of G and the regulation by WP5 or pH conditions was applied as information encryption material, rewritable paper, and erasable ink. We believe that this fluorescence regulation strategy is promising for the construction of advanced fluorescent organic materials.

A sequential light-harvesting system with thermosensitive colorimetric emission in both aqueous solution and hydrogel

Inspired by natural photosynthetic systems that feature both sequential energy transfer and temperature response, we herein report an artificial thermosensitive sequential light-harvesting system (LHS) based on an amphiphilic molecule TPEO. It self-assembles into fluorescent nanoparticles in water and shows tunable LCST behavior. By loading ESY as the first acceptor and NiR as the second acceptor into the nanoparticles, an artificial LHS with two-step FRET was successfully constructed. Interestingly, the system exhibits thermosensitive colorimetric fluorescence in both aqueous solution and hydrogel by taking advantage of a combination of LCST and sequential FRET.

A time-multiplexed self-erasing nanopaper for water induced information transmission

The progressive presentation of multilevel information enhances the security level of information storage and transmission. Here, a time-multiplexed self-erasing nanopaper was developed by integrating cellulose nanofiber (CNF)-stabilized gold nanoclusters and CNF-modified long afterglow materials. The orange fluorescence of gold nanoclusters on nanopaper was regulated by the reversible swelling and shrinking of CNF induced by water solution, while the cyan fluorescence of micron-long afterglow remained stable and acted as the background signal. It was noteworthy that the fluorescence colour and intensity of the nanopaper could be freely adjusted between orange and cyan on the time scale. Therefore, the array information on the nanopaper could be encoded by a water solution, iterated variation as the step-by-step solvent volatilized on the time scale measured by the time of the afterglow duration. This work provides a new approach for constructing time-multiplexed self-erasing nanopaper for confidential information storage and transmission.

Spatially and Temporally Programmable Transparency Evolutions in Hydrogels Enabled by Metal Coordination toward Transient Anticounterfeiting

Hydrogels have emerged as promising candidates for anticounterfeiting materials, owing to their unique stimulus-responsive capabilities. To improve the security of encrypted information, efforts are devoted to constructing transient anticounterfeiting hydrogels with a dynamic information display. However, current studies to design such hydrogel materials inevitably include sophisticated chemistry, complex preparation processes, and particular experimental setups. Herein, a facile strategy is proposed to realize the transient anticounterfeiting by constructing bivalent metal (M2+)-coordination complexes in poly(acrylic acid) gels, where the cloud temperature (Tc) of the gels can be feasibly tuned by M2+ concentration. Therefore, the multi-Tc parts in the gel can be locally programmed by leveraging the spatially selective diffusion of M2+ with different concentrations. With the increase of temperature or the addition of a complexing agent, the transparency of the multi-Tc parts in the gel spontaneously evolves in natural light, enabling the transient information anticounterfeiting process. This work has provided a new strategy and mechanism to fabricate advanced anticounterfeiting hydrogel materials.

Viscoelasticity‐Controlled Relaxation in Wrinkling Surface for Multistage Time‐Resolved Optical Information Encryption

As counterfeit techniques continue to evolve, ensuring the security of conventional "static" encryption methods becomes increasingly challenging. Here, the viscoelasticity-controlled relaxation is introduced for the first time in a bilayer wrinkling system by regulating the density of hydrogen bond networks in polymer to construct a "dynamic" encryption material. The wrinkling surface can manipulate light during the dynamic relaxation process, exhibiting three stages with frosted glass, structural color, and mirror reflection. By regulating the viscoelasticity of skin layer through UV irradiation, the wavelength and the relaxation rate of the wrinkles can be controlled. As a result, dynamic wrinkling anti-counterfeiting patterns and time-resolved multistage information encryption are achieved. Crucially, the encryption material is developed as an anti-counterfeiting label for packing boxes in daily applications, allowing the encrypted information to be activated manually and identified by naked eyes, surpassing the existing time-resolved encryption materials in utilization potential. Besides, the dynamic hydrogen bond networks are extended to various dynamic interaction networks, demonstrating the versatility of the dynamic encryption strategy. This work not only provides an additional dimension for dynamic information encryption in daily practical use, but also offers theoretical guidance for the development of advanced optical anti-counterfeiting and smart display materials in the future.

Polarization-Dependent Thin Films with Biaxial Anisotropic Absorption Constructed by a Single Coating and Subsequent Topochemical Polymerization of Chromophores

For the construction of hierarchical superstructures with biaxial anisotropic absorption, a newly synthesized diacetylene-functionalized bipyridinium is self-assembled to use an electron-accepting host for capturing and arranging guests. The formation of the donor-acceptor complex triggers an intermolecular charge transfer, leading to chromophore activation. Polarization-dependent multichroic thin films are prepared through a sequential process of single-coating, self-assembly, and topochemical polymerization of host-guest chromophores. Molecular packing structures constructed in the single-layer optical thin film possess orthogonal absorption axes for two different wavelengths. By tuning the linear polarization angle, the color of the optical thin film can be intentionally controlled. This single-layered multichroic film provides a new pathway for the development of anticounterfeiting and multiplexing encryptions.

Molecular circuit for exponentiation based on the domain coding strategy

DNA strand displacement (DSD) is an efficient technology for constructing molecular circuits. However, system computing speed and the scale of logical gate circuits remain a huge challenge. In this paper, a new method of coding DNA domains is proposed to carry out logic computation. The structure of DNA strands is designed regularly, and the rules of domain coding are described. Based on this, multiple-input and one-output logic computing modules are built, which are the basic components forming digital circuits. If the module has n inputs, it can implement 2n logic functions, which reduces the difficulty of designing and simplifies the structure of molecular logic circuits. In order to verify the superiority of this method for developing large-scale complex circuits, the square root and exponentiation molecular circuits are built. Under the same experimental conditions, compared with the dual-track circuits, the simulation results show that the molecular circuits designed based on the domain coding strategy have faster response time, simpler circuit structure, and better parallelism and scalability. The method of forming digital circuits based on domain coding provides a more effective way to realize intricate molecular control systems and promotes the development of DNA computing.

Full-Color Circularly Polarized Luminescence of Supramolecular Polymers with Handedness Inversion Regulated by Anion and Temperature

Constructing full-color circularly polarized luminescence (CPL) materials with switchable handedness in the solid state is an appealing yet considerably challenging task, especially for supramolecular polymer films assembled from homochiral monomers. Herein, supramolecular polymers with full-color CPL and inverted handedness are realized through the coassembly of a homochiral cholesterol derivative (PVPCC), metal ions (Zn2+), and achiral fluorescent dyes. The obtained coassembled systems show anion-directed supramolecular chirality inversion by exchanging the anions of NO3-, ClO4-, BF4-, and Cl-. For instance, the negative CD and right-handed CPL are detected in the PVPCC/Zn(NO3)2 aggregates, which convert into positive CD and left-handed CPL after introducing Cl-, corresponding to the transformation from nanorods to nanofibers. Furthermore, the tunable CPL color and handedness inversion of the coassembly system of PVPCC/Zn(NO3)2 and achiral fluorescent dyes can be established by alternately changing the assembling temperature of 298 and 273 K. Importantly, the full-color CPL polymeric materials are then constructed by doping the PVPCC/Zn(NO3)2/dyes complexes into poly(methyl methacrylate) (PMMA) film, which maintains the handedness inversion and shows the enhanced CPL performance. The work not only deepens the understanding of chirality inversion in supramolecular chemistry but also helps to construct full-color CPL materials with switchable handedness from homochiral building blocks in materials science.

Stimulus-responsive polymer materials toward multi-mode and multi-level information anti-counterfeiting: recent advances and future challenges

Information storage and security is one of the perennial hot issues in society, while the further advancements of related chemical anti-counterfeiting systems remain a formidable challenge. As emerging anti-counterfeiting materials, stimulus-responsive polymers (SRPs) have attracted extensive attention due to their unique stimulus-responsiveness and charming discoloration performance. At the same time, single-channel decryption technology with low-security levels has been unable to effectively prevent information from being stolen or mimicked. As a result, it would be of great significance to develop SRPs with multi-mode and multi-level anti-counterfeiting characteristics. This study summarizes the latest achievements in advance anti-counterfeiting strategies based on SRPs, including multi-mode anti-counterfeiting (static information) and multi-level anti-counterfeiting (dynamic information). In addition, the promising applications of such materials in anti-counterfeiting labels, identification platforms, intelligent displays, and others are briefly reviewed. Finally, the challenges and opportunities in this emerging field are discussed. This review serves as a useful resource for manipulating SRP-based anti-counterfeiting materials and creating cutting-edge information security and encryption systems.

Living Materials Based Dynamic Information Encryption via Light-Inducible Bacterial Biosynthesis of Quantum Dots

Microbial biosynthesis, as an alternative method for producing quantum dots (QDs), has gained attention because it can be conducted under mild and environmentally friendly conditions, distinguishing it from conventional chemical and physical synthesis approaches. However, there is currently no method to selectively control this biosynthesis process in a subset of microbes within a population using external stimuli. In this study, we have attained precise and selective control over the microbial biosynthesis of QDs through the utilization of an optogenetically engineered Escherichia coli (E. coli). The recombinant E. coli is designed to express smCSE enzyme, under the regulation of eLightOn system, which can be activated by blue light. The smCSE enzymes use L-cysteine and Cd2+ as substrates to form CdS QDs. This system enables light-inducible bacterial biosynthesis of QDs in precise patterns within a hydrogel for information encryption. As the biosynthesis progresses, the optical characteristics of the QDs change, allowing living materials containing the recombinant E. coli to display time-dependent patterns that self-destruct after reading. Compared to static encryption using fluorescent QD inks, dynamic information encryption based on living materials offers enhanced security.

Light and Humidity Dual-Responsive Anti-Counterfeiting Films Based on Hydrogen-Bonded Cholesteric Liquid Crystal Polymers with Spiropyran

There is still significant room for improvement when combining structural color with fluorescence patterns in dual anti-counterfeiting and dynamic anti-counterfeiting labels. In this study, we achieved significant breakthroughs under dual anti-counterfeiting conditions by using the structural color properties of the hydrogen-bonded cholesteric liquid crystal (HBCLC) and combining them with the fluorescence dye spiropyran (SP) to create anti-counterfeiting patterns. The anti-counterfeiting label can only display storage information after meeting the conditions of humidity and ultraviolet light (UV) and has the functions of dynamic encryption and repeated reading. We adjusted the center of the reflection band of the HBCLC film to transition from red to infrared under 40-90% relative humidity (RH) conditions and used it as a background film to draw anti-counterfeiting patterns with SP. Since these fluorescence dyes can switch between merocyanine (MC) (red) and SP (colorless) under UV and visible light conditions, when combined with the HBCLC, orthogonal dynamic encryption was achieved. Additionally, with the adsorption of SP, the reflection band of HBCLC films under the same humidity range increased from around 160 nm to around 260 nm, greatly improving the sensitivity to humidity changes. Furthermore, under UV conditions, it can still emit red fluorescence, demonstrating a polymorphic encryption feature, which greatly increased the complexity of the anti-counterfeiting pattern with significant significance to dynamic anti-counterfeiting and information storage.

Excitation wavelength-dependent multi-coloured and white-light emissive pyrene-based hydrazones: suppression of Kasha's rule

Multi-coloured and white-light emissions from pyrene-based hydrazones are described. They exhibit excitation wavelength-dependent emissions in solution due to the suppression of Kasha's rule. Interestingly, in dimethylformamide, 1-3 emit light that covers all the regions of primary colours as a function of excitation wavelength, and 1 and 2 emit white light (λex = 420 nm) in isopropanol.

Photoswitchable and Reversible Fluorescent Eutectogels for Conformal Information Encryption

Smart fluorescent materials that can respond to environmental stimuli are of great importance in the fields of information encryption and anti-counterfeiting. However, traditional fluorescent materials usually face problems such as lack of tunable fluorescence and insufficient surface-adaptive adhesion, hindering their practical applications. Herein, inspired by the glowing sucker octopus, we present a novel strategy to fabricate a reversible fluorescent eutectogel with high transparency, adhesive and self-healing performance for conformal information encryption and anti-counterfeiting. Using anthracene as luminescent unit, the eutectogel exhibits photoswitchable fluorescence and can therefore be reversibly written/erased with patterns by non-contact stimulation. Additionally, different from mechanically irreversible adhesion via glue, the eutectogel can adhere to various irregular substrates over a wide temperature range (-20 to 65 °C) and conformally deform more than 1000 times without peeling off. Furthermore, by exploiting surface-adaptive adhesion, high transparency and good stretchability of the eutectogel, dual encryption can be achieved under UV and stretching conditions to further improve the security level. This study should provide a promising strategy for the future development of advanced intelligent anti-counterfeiting materials.

A Rule for Response Sensitivity of Structural-Color Photonic Colloids

To mimic natural photonic crystals having color regulation capacities dynamically responsive to the surrounding environment, periodic assembly structures have been widely constructed with response materials. Beyond monocomponent materials with stimulus responses, binary and multiphase systems generally offer extended color space and complex functionality. Constructing a rule for predicting response sensitivity can provide great benefits for the tailored design of intelligently responsive photonic materials. Here, we elucidate mathematical relationships between the response sensitivity of dynamically structural-color changes and the location distances of photonic co-phases in three-dimensional Hansen space that can empirically express the strength of their interaction forces, including dispersion force, polarity force, and hydrogen bonding. Such an empirical rule is proven to be applicable for some typical alcohols, acetone, and acetic acid regardless of their molecular structures, as verified by angle resolution spectroscopy, in situ infrared spectroscopy, and molecular simulation. The theoretical method we demonstrate provides rational access to custom-designed responsive structural coloration.

Dynamic Color-Switching of Hydrogel Micropillar Array under Ethanol Vapor for Optical Encryption

Responsive structural colors from artificially engineered micro/nanostructures are critical to the development of anti-counterfeiting, optical encryption, and intelligent display. Herein, the responsive structural color of hydrogel micropillar array is demonstrated under the external stimulus of ethanol vapor. Micropillar arrays with full color are fabricated via femtosecond laser direct writing by controlling the height and diameter of the micropillars according to the FDTD simulation. Color-switching of the micropillar arrays is achieved in <1 s due to the formation of liquid film among micropillars. More importantly, the structural color blueshift of the micropillar arrays is sensitive to the micropillar diameter, instead of the micropillar height. The micropillar array with a diameter of 772 nm takes 400 ms to complete blueshift under ethanol vapor, while that with a diameter of 522 nm blueshifts at 2400 ms. Microscale patterns are realized by employing the size-dependent color-switching of designed micropillar arrays under ethanol vapor. Moreover, Morse code and directional blueshift of structural colors are realized in the micropillar arrays. The advantages of controllable color-switching of the hydrogel micropillar array would be prospective in the areas of optical encryption, dynamic display, and anti-counterfeiting.

A General Strategy for Developing Ultrasensitive "Transistor-Like" Thermochromic Fluorescent Materials for Multilevel Information Encryption

Thermochromic fluorescent materials (TFMs) exhibit great potential in information encryption applications but are limited by low thermosensitivity, poor color tunability, and a wide temperature-responsive range. Herein, a novel strategy for constructing highly sensitive TFMs with tunable emission (450-650 nm) toward multilevel information encryption is proposed, which employs polarity-sensitive fluorophores with donor-acceptor-donor (D-A-D) type structures as emitters and long-chain alkanes as thermosensitive loading matrixes. The structure-function relationships between the performance of TFMs and the structures of both fluorescent emitters and phase-change molecules are systematically studied. Benefiting from the above design, the obtained TFMs exhibit over 9500-fold fluorescence enhancement toward the temperature change, as well as ultrahigh relative temperature sensitivity up to 80% K-1 , which are first confirmed. Thanks to the superior transducing performance, the above-prepared TFMs can be further developed as information-storage platforms within a relatively narrow interval of temperature variation, including temperature-dominated multicolored information display and multilevel information encryption. This work will not only provide a novel perspective for designing superior TFMs for information encryption but also bring inspiration to the design and preparation of other response-switching-type fluorescent probes with ultrahigh conversion efficiency.

Super Adhesive Fluorescent Materials for Encrypted Messages, Underwater Leak Repair, and Their Potential Application in Fluorescent Tattoos

Achieving high-performance luminescence for underwater bonding remains a significant challenge in materials science. This study addresses this issue by synthesizing a luminescent material based on an aggregation-induced emission (AIE) monomer and copolymerizing it with lipoic acid (LA) to create an AIE supramolecular polymer. The resulting copolymer exhibits strong fluorescence under ultraviolet (UV) irradiation at 365 nm due to the AIE of TPEE and enables underwater adhesion. The P(LA-TPEE) polymer demonstrates potential for digital encryption and decryption of quick response (QR) codes underwater. Furthermore, it can dissolve well in anhydrous ethanol, producing an environment-friendly and super waterproof adhesive. Most notably, the P(LA-TPEE) solution can be sprayed on human skin, creating an invisible tattoo that only became visible under UV light due to the hydrogen bond (H-bond) and π-π structures. This smart tattoo can be quickly wiped away with alcohol, avoiding the painful and harmful process of tattoo removal. It can also be repeatedly applied to draw the preferred tattoo pattern. This AIE supramolecular polymer shows great potential in underwater adhesion and repair, underwater message encryption, and non-toxic and painless invisible tattooing. Overall, this study provides a valuable approach for material design in the future.

A transient vesicular glue for amplification and temporal regulation of biocatalytic reaction networks

Regulation of enzyme activity and biocatalytic cascades on compartmentalized cellular components is key to the adaptation of cellular processes such as signal transduction and metabolism in response to varying external conditions. Synthetic molecular glues have enabled enzyme inhibition and regulation of protein-protein interactions. So far, all the molecular glue systems based on covalent interactions operated under steady-state conditions. To emulate dynamic biological processes under dissipative conditions, we introduce herein a transient supramolecular glue with a controllable lifetime. The transient system uses multivalent supramolecular interactions between guanidinium group-bearing surfactants and adenosine triphosphate (ATP), resulting in bilayer vesicle structures. Unlike the conventional chemical agents for dissipative assemblies, ATP here plays the dual role of providing a structural component for the assembly as well as presenting active functional groups to "glue" enzymes on the surface. While gluing of the enzymes on the vesicles achieves augmented catalysis, oscillation of ATP concentration allows temporal control of the catalytic activities similar to the dissipative cellular nanoreactors. We further demonstrate temporal upregulation and control of complex biocatalytic reaction networks on the vesicles. Altogether, the temporal activation of biocatalytic cascades on the dissipative vesicular glue presents an adaptable and dynamic system emulating heterogeneous cellular processes, opening up avenues for effective protocell construction and therapeutic interventions.

Lanthanide Metal-Organic Framework Isomers with Novel Water-Boosting Lanthanide Luminescence Behaviors

Lanthanide metal-organic frameworks (Ln-MOFs) with exceptional optical performance and structural diversity offer a unique platform for the development of luminescent materials. However, Ln-MOFs often suffer from luminescence quenching by high-vibrating oscillators, especially in aqueous solution. Thus, multiple strategies have been adopted to improve the luminescence of Ln3+. Anomalous research about water-induced lanthanide luminescence enhancement of Ln-MOFs is in the primary stage. Here, two Eu-based metal-organic framework (Eu-MOF) isomers named QXBA-Eu-1 and QXBA-Eu-2 were constructed by using the same ligand under different solvent thermal conditions, which exhibited distinctive water- and methanol-boosting emission behaviors. As for QXBA-Eu-1, water and methanol molecules replaced the free N,N-dimethylacetamide (DMA) molecules in the framework, repressed the rotation or libration suppression of the QXBA linker, and formed hydrogen bonds with the coordinated water molecules, which suppressed the O-H high-energy vibrations, reduced nonradiative transitions, stabilized the T1 state, and facilitated the intersystem crossing (ISC) process. For QXBA-Eu-2, water molecules tended to replace the coordinated DMA ligands, which altered the S1 and T1 energy levels of the ligand and facilitated the ligand-to-metal energy transfer (LMET) process and strengthened the luminescence of Eu3+. Importantly, free solvent molecules and the hydroxylation of Eu3+ centers also restrained the rotation or libration of the QXBA linker, by which the nonradiative transition was further inhibited and the lanthanide luminescence enhanced. Thus, this work not only opened an unprecedented path to enhance lanthanide luminescence in aqueous solution but also expanded its application scope.

High-Temperature, Reversible, and Robust Thermochromic Fluorescence Based on Rb2 MnBr4 (H2 O)2 for Anti-Counterfeiting

Thermochromic fluorescent materials (TFMs) characterized by noticeable emission color variation with temperature have attracted pervasive attention for their frontier application in stimulus-response and optical encryption technologies. However, existing TFMs typically suffer from weak PL reversibility as well as limited mild operating temperature and severe temperature PL quenching. PL switching under extreme conditions such as high temperature will undoubtedly improve encryption security, while it is still challenging for present TFMs. In this work, high-temperature thermochromic fluorescence up to 473 K and robust structural and optical reversibility of 80 cycles are observed in Rb2 MnBr4 (H2 O)2 and related crystals, which is seldom reported for PL changes at such a high temperature. Temperature-driven nonluminous, red and green light emission states can be achieved at specific temperatures and the modulation mechanism is verified by in situ optical and structural measurements and single particle transition. By virtue of this unique feature, a multicolor anti-counterfeiting label based on a broad temperature gradient and multidimensional information encryption applications are demonstrated. This work opens a window for the design of inorganic materials with multi-PL change and the development of advanced encryption strategies with extreme stimuli source.

Solvent-Directed Hierarchical Self-Assembly of Tetraphenylpyrazine-Cholesterol with Amplified Circularly Polarized Luminescence

It is important to identify the effect of assembly and aggregation on the chirality transfer and energy transmission in supramolecular polymer system, since the unordered aggregation is insufficient to promote luminescence enhancement and chirality transfer, even causing the negative effect. Another key issue is to identify the solvent effect on hierarchically chiral self-assembly. Herein, we designed an AIE-core based building block, tetraphenylpyrazine-cholesterol (TPP-Chol), to explore how the solvent component influences chirality transfer and energy transmission of its aggregates and/or assemblies. Interestingly, the hierarchical assembly behavior was realized in the mixture of MeOH/CHCl3 highly dependent on the MeOH content. During the solvent-directed hierarchical assembly, the morphologic transformations, such as nanoribbons with a width of 150 nm, twisted nanoribbons with helical pitch of 420 nm, nanoribbon clusters, and microflowers with an average diameter of 5.5 μm, were realized with obvious chirality amplification for both circular dichroism (CD) and circularly polarized luminescence (CPL) measurements. The hierarchical assembly of TPP-Chol was also demonstrated by a time-dependent CD test. The work points out the complexity and dynamic of hierarchically chiral self-assembly regulated by the solvent effect, which would be helpful for the development of supramolecular materials with enhanced CPL performance and dynamic chirality.

Bio-Inspired Electro-Thermal-Hygro Responsive Rewritable Systems with Temporal/Spatial Control for Environment-Interactive Information Display

Utilization of rewritable luminescent materials for secure information storage and delivery has long been envisaged to reduce the cost and environmental wastes. However, it remains challenging to realize a temporally/spatially controlled display of the written information, which is crucial for secure information encryption. Here, inspired by bioelectricity-triggered skin pattern switching in cephalopods, an ideal rewritable system consisting of conductive graphene film and carbon dots (CDs) gel with blue-to-red fluorescence-color changes via water-triggered CDs aggregation and re-dispersion is presented. Its rewritability is guaranteed by using water ink to write on the CDs-gel and employing Joule heat of graphene film to evaporate water. Due to the highly controlled electrical stimulus, temporally/spatially controlled display is achieved, enabling on-demand delivery and duration time regulation of the written information. Furthermore, new-concept environment-interactive rewritable system is obtained by integrating sensitive acoustic/optical sensors and multichannel electronic time-delay devices. This work opens unprecedented avenues of rewritable systems and expands potential uses for information encryption/delivery.

Photo-triggered full-color circularly polarized luminescence based on photonic capsules for multilevel information encryption

Materials with phototunable full-color circularly polarized luminescence (CPL) have a large storage density, high-security level, and enormous prospects in the field of information encryption and decryption. In this work, device-friendly solid films with color tunability are prepared by constructing Förster resonance energy transfer (FRET) platforms with chiral donors and achiral molecular switches in liquid crystal photonic capsules (LCPCs). These LCPCs exhibit photoswitchable CPL from initial blue emission to RGB trichromatic signals under UV irradiation due to the synergistic effect of energy and chirality transfer and show strong time dependence because of the different FRET efficiencies at each time node. Based on these phototunable CPL and time response characteristics, the concept of multilevel data encryption by using LCPC films is demonstrated.

Multimodal dynamic and unclonable anti-counterfeiting using robust diamond microparticles on heterogeneous substrate

The growing prevalence of counterfeit products worldwide poses serious threats to economic security and human health. Developing advanced anti-counterfeiting materials with physical unclonable functions offers an attractive defense strategy. Here, we report multimodal, dynamic and unclonable anti-counterfeiting labels based on diamond microparticles containing silicon-vacancy centers. These chaotic microparticles are heterogeneously grown on silicon substrate by chemical vapor deposition, facilitating low-cost scalable fabrication. The intrinsically unclonable functions are introduced by the randomized features of each particle. The highly stable signals of photoluminescence from silicon-vacancy centers and light scattering from diamond microparticles can enable high-capacity optical encoding. Moreover, time-dependent encoding is achieved by modulating photoluminescence signals of silicon-vacancy centers via air oxidation. Exploiting the robustness of diamond, the developed labels exhibit ultrahigh stability in extreme application scenarios, including harsh chemical environments, high temperature, mechanical abrasion, and ultraviolet irradiation. Hence, our proposed system can be practically applied immediately as anti-counterfeiting labels in diverse fields.

Photoinduced Radical Persistent Luminescence in Semialiphatic Polyimide System with Temperature and Humidity Resistance

Organic persistent luminescence (pL) systems with photoresponsive dynamic features have valuable applications in the fields of data encryption, anticounterfeiting, and bioimaging. Photoinduced radical luminescent materials have a unique luminous mechanism with the potential to achieve dynamic pL. It is extremely challenging to obtain radical pL under ambient conditions; on account of it, it is unstable in air. Herein, a new semialiphatic polyimide-based polymer (A0) is developed, which can achieve dynamic pL through reversible conversion of radical under photoexcitation. A "joint-donor-spacer-acceptor" molecular design strategy is applied to effectively modulate the intramolecular charge-transfer and charge-transfer complex interactions, resulting in effective protection of the radical generated under photoirradiation. Meanwhile, polyimide-based polymers of A1-A4 are obtained by doping different amine-containing fluorescent dyes to modulate the dynamic afterglow color from green to red via the triplet to singlet Förster resonance energy-transfer pathway. Notably, benefiting from the structural characteristics of the polyimide-based polymer, A0-A4 have excellent processability, thermal stability, and mechanical properties and can be applied directly in extreme environments such as high temperatures and humidity.

Intelligent Colorimetric Indicators for Quality Monitoring and Multilevel Anticounterfeiting with Kinetics-Tunable Fluorescence

The spoilage and forgery of perishable products such as food, drugs, and vaccines cause serious health hazards and economic loss every year. Developing highly efficient and convenient time-temperature indicators (TTIs) to realize quality monitoring and anticounterfeiting simultaneously is urgent but remains a challenge. To this end, a kind of colorimetric fluorescent TTI, based on CsPbBr₃@SiO₂ nanoparticles with tunable quenching kinetics, is developed. The kinetics rate of the CsPbBr₃-based TTIs is easily regulated by adjusting temperature, concentration of the nanoparticles, and addition of salts, stemming from the cation exchange effect, common-ion effect, and structural damage by water. Typically, when combined with europium complexes, the developed TTIs show an irreversible dynamic change in fluorescent colors from green to red upon increasing temperature and time. Furthermore, a locking encryption system with multiple logics is also realized by combining TTIs with different kinetics. The correct information only appears at specific ranges of time and temperature under UV light and is irreversibly self-erased afterward. The simple and low-cost composition and the ingenious design of kinetics-tunable fluorescence in this work stimulate more insights and inspiration toward intelligent TTIs, especially for high-security anticounterfeiting and quality monitoring, which is really conducive to ensuring food and medicine safety.

Heat-Resistant and Color-Changing Luminescent Polysulfone for Information Encryption and Fire Alarming

An intrinsic difficulty with thermally responsive photoluminescent materials is that high temperatures usually destroy luminance due to the notorious thermal quenching effect. Limited by the vulnerable chemical structure and soft skeleton, most of the existing photoluminescent responsive materials fail to indicate or work at a surging temperature over 100 °C, thus limiting application in display and alarming in harsh conditions. Herein, enlightened by chameleon's adaptive nature to external stimulus, we introduce a topologically optimized electron donor-acceptor (DA) structure and supramolecular interactions of lanthanide ions into the polymer backbone. The emission color determined by the DA structure is stable at high temperatures, and metal-ligand interaction phosphorescence is temperature-adjustable. Owing to the excellent reproducibility and heat resistance of composite films, the sensors can be bent into different three-dimensional structures and adhered to metal surfaces as flexible thermometers with superior display resolution. The polymer composite film could be directly applied as a photoluminescent quick response (QR) code, with patterns simultaneously variable to a temperature from 30 to 150 °C free of manual operation. More importantly, the polymeric composite could be in-situ-oxidized to a "sulfone" structure with an enhanced glass transition temperature of 297-304 °C. The heat- and flame-resistant characteristics of the oxidized films give rise to the application of fire alarming devices since it can locate the fire source and respond exactly depending on the distance from the fire. The unique display, encryption, and alarming functions of the polymeric composite studied in this work bring forward a new concept of developing a great information security and disaster monitoring system with the application of temperature-responsive materials.

Orthogonal Photochemistry toward Direct Encryption of a 3D-Printed Hydrogel

Encryption technologies are essential for information security and product anti-counterfeiting, but they are typically restricted to planar surfaces. Encryption on complex 3D objects offers great potential to further improve security. However, it is rarely achieved owing to the lack of encoding strategies for nonplanar surfaces. Here, an approach is reported to directly encrypt on a 3D-printed object employing orthogonal photochemistry. In this system, visible light photochemistry is used for 3D printing of a hydrogel, and ultraviolet light is subsequently employed to activate its geometrically complex surface through the dissociation of ortho-nitrobenzyl ester units in a spatioselective manner for information coding. This approach offers a new way for more reliable encryption, and the underlying orthogonal photochemistry can be extended toward functional modification of 3D-printed products beyond information protection.

Proton transfer network with luminescence display controls OFF/ON catalysis that generates a high-speed slider-on-deck

A three-component network for OFF/ON catalysis was built from a protonated nanoswitch and a luminophore. Its activation by addition of silver(i) triggered the proton-catalyzed formation of a biped and the assembly of a fast slider-on-deck (k ₂₉₈ = 540 kHz).

Dendritic Quaternary-Encoded Oligourethanes for Data Encryption

The use of sequence-defined digital polymers for data storage and encryption has received increasing attention due to their precision structures similar to natural biomacromolecules (e.g., DNA) but increased stability. However, the rapid development of sequencing techniques raises the concern of information leakage. Herein, dendritic quaternary-encoded oligourethanes bearing a photoresponsive trigger, self-immolative backbones, and a mass spectrometry tag of PEG dendron have been developed for data encryption. Although the sequence information in linear analogs can be readily deciphered by mass spectrometry, sequencing of dendritic oligourethanes cannot be achieved by either primary MS or tandem MS/MS owing to the unique spatial conformation. Intriguingly, the fragmentation pathways of a quaternary dendrimer under MS/MS conditions can be converted to 2772-bit 2D matrices with ≈1.98×10⁸⁷ permutations, serving as high-strength encryption keys for highly reliable data encryption.

A Dynamic Supramolecular H-bonding Network with Orthogonally Tunable Clusteroluminescence

Enabling dynamically tunable emissive systems offers opportunities for constructing smart materials. Clusteroluminescence, as unconventional luminescence, has attracted increasing attention in both fundamental and applied sciences. Herein, we report a supramolecular poly(disulfides) network with tunable clusteroluminescence. The reticular H-bonds synergize the rigidity and mobility of dynamic networks, and endow the resulting materials with mechanical adaptivity and robustness, simultaneously enabling efficient clusteroluminescence and phosphorescence at 77 K. Orthogonally tunable luminescence are achieved in two manners, i.e., slow backbone disulfide exchange and fast side-chain metal coordination. Further exploration of the reprocessability and chemical closed-loop recycling of intrinsic dynamic networks for sustainable materials is feasible. We foresee that the synergistic strategy of dynamic chemistry offers a novel pathway and potential opportunities for smart emissive materials.

Supramolecular Polymers with Photoswitchable Multistate Fluorescence for Anti-Counterfeiting and Encryption

Photoswitchable fluorescent materials are desirable for many applications because their emission signals can be easily modulated on demand. In this study, novel photoswitchable multistate fluorescent supramolecular polymers (PMFSPs) were prepared via host-guest interactions under a facile ultrasonication strategy. In the system, photochromic fluorescent diarylethylene monomer (SDTE, donor) and adamantane-containing monomer (BAC) were covalently combined into the backbone of the guest polymer (P1) via radical copolymerization. Meanwhile, the host moiety (CDSP, acceptor) was synthesized by covalent incorporation of photochromic spiropyran dye (SPCOOH) with β-cyclodextrin. By adjusting the stimulation wavelength and utilizing photoinduced fluorescence resonance energy transfer (FRET), the supramolecular polymers can undergo reversible tristate fluorescence switching among none, red, and green. In addition, due to the high contrast, rapid photoresponsiveness and prominent photoreversibility of the prepared PMFSPs, we demonstrated that they have great potential in advanced anti-counterfeiting and multilevel information encryption.

Dynamic Timing Control of Molecular Photoluminescent Systems

Dynamic control of molecular photoluminescence offers chemical solutions to designing functional emissive materials. Although stimuli-switchable molecular luminescent systems are well established, how to encode these dynamic emissive systems with a "timing" feature, that is, time-dependent luminescent properties, remains challenging. This Concept aims to summarize the design principles of dynamic timing molecular photoluminescent systems by discussing the state-of-the-art of this topic and the shaping of fabrication strategies at both the molecular and supramolecular levels. An outlook and perspectives are given to outline the future opportunities and challenges in the rational design and potential applications of these smart emissive systems.

Multicolor emission based on a N, N'-Disubstituted dihydrodibenzo [a, c] phenazine crown ether macrocycle

Dynamic fluorophore 9,14-diphenyl-9,14-dihydrodibenzo[a,c]phenazine (DPAC) affords a new platform to produce diverse emission outputs. In this paper, a novel DPAC-containing crown ether macrocycle D-6 is synthesized and characterized. Host-guest interactions of D-6 with different ammonium guests produced a variety of fluorescence with hypsochromic shifts up to 130 nm, which are found to be affected by choice of solvent or guest and host/guest stoichiometry. Formation of supramolecular complexes were confirmed by UV-vis titration, ¹H NMR and HRMS spectroscopy.

AIEgen-Enabled Multicolor Visualization for the Formation of Supramolecular Polymer Networks

Extensive reports on the use of supramolecular polymer networks (SPNs) in self-healing materials, controlled release system and degradable products have led more researchers to tap their potential owing to the unique properties. Yet, the attendant efforts in the visualization through conventional luminescence methods during the formation of SPNs have been met with limited success. Herein, we designed a special type of SPNs prepared by PPMU polymer chains containing pyrene benzohydrazonate (PBHZ) molecules as AIEgens for the multicolor visualization with naked eyes. The complete detection of the formation process of the networks relied on the PBHZ molecules with aggregation-induced ratiometric emission (AIRE) effect, which enabled the fluorescence of the polymer networks transits from blue to cyan, and then to green with the increasing crosslinking degree derived from the hydrogen bonds between 2-ureido-4-pyrimidone (UPy) units of the polymer chains. Additionally, we certificated the stimuli-responsiveness of the obtained SPNs, and the fluorescence change, as well as observing the morphology transition. The AIEgen-enabled multicolor visualization of the formation of SPNs may provide better understanding of the details of the crosslinking interactions in the microstructural evolution, giving more inspiration for the multifunctional products based on SPNs.