Solution‐pH‐Modulated Rectification of Ionic Current in Highly Ordered Nanochannel Arrays Patterned with Chemical Functional Groups at Designed Positions

A new ionic current rectification device responsive to a broad range of pH stimuli is established using highly ordered nanochannels of porous anodic alumina membrane with abrupt surface charge discontinuity. The asymmetric surface charge distribution is achieved by patterning the nanochannels with surface amine functional groups at designed positions using a two‐step anodization process. Due to the protonation/deprotonation of the patterned amine and the remaining intrinsic hydroxyl groups upon solution pH variation, the nanochannel‐array‐based device is able to regulate ion transport selectivity and has ionic current rectification properties. The rectification ratio of the device is mainly determined by the nanochannel size, and the rectification ratio is less sensitive to the patterned length of the amine groups when the nanochannels size is defined. Thus, the isoelectric point of nanochannels can be easily estimated to be the pH value with a unit rectification ratio. The present ionic device is promising for biosensing, molecular transport and separation, and drug delivery in confined environments.     

Bioinspired Self‐Gating Nanofluidic Devices for Autonomous and Periodic Ion Transport and Cargo Release

The biochemical oscillatory reaction induced self‐gating process of biological ion channels is essential to life processes, characterized as autonomous, continuous, and periodic. However, few synthetic nanochannel systems can achieve such excellent self‐gating property. Their gating properties work greatly depending on the frequent addition of reactants or the supply of external stimuli. Herein, a novel bioinspired self‐gating nanofluidic device that can transport mass in a continuous and periodic manner is reported. This self‐gating device is constructed by using a fully closed‐system pH oscillator to control the gating processes of the artificial proton‐gated nanochannels. With cyclic oscillation of protons inside the nanochannel induced by the oscillatory chemical reactions of the pH oscillator, surface charge density and polarity of the nanochannels can be self‐regulated, resulting in an autonomous and periodic switching of the nanochannel conductance between high and low states as well as the selectivity between cation selective and anion selective states. Moreover, by using Rhodamine B and Ruthenium(II) compound as the cationic cargoes, periodic release of these charged molecules is also observed. Therefore, this work opens up a new avenue to build self‐gating nanofluidic devices, which may not only act as ion oscillators, but potentially find applications in controlled‐release fields as well.     

Bio‐Inspired All‐Organic Soft Actuator Based on a π–π Stacked 3D Ionic Network Membrane and Ultra‐Fast Solution Processing

Next generation electronic products, such as wearable electronics, flexible displays, and smart mobile phones, will require the use of unprecedented electroactive soft actuators for haptic and stimuli‐responsive devices and space‐saving bio‐mimetic actuation. Here, a bio‐inspired all‐organic soft actuator with a π–π stacked and 3D ionic networked membrane based on naphthalene‐tetracarboxylic dianhydride (Ntda) and sulfonated polyimide block copolymers (SPI) is presented, utilizing an ultra‐fast solution process. The π–π stacked and self‐assembled 3D ionic networked membrane with continuous and interconnected ion transport nanochannels is synthesized by introducing simple and strong atomic level regio‐specific interactions of hydrophilic and hydrophobic SPI co‐blocks with cations and anions in the ionic liquid. Furthermore, a facile and ultrafast all‐solution process involving solvent blending, dry casting, and solvent dropping is developed to produce electro‐active soft actuators with highly conductive polyethylenedioxythiophene (PEDOT):polystyrenesulfonate (PSS) electrodes. Ionic conductivity and ion exchange capacity of the π–π stacked Ntda‐SPI membrane can be increased up to 3.1 times and 3.4 times of conventional SPI, respectively, resulting in a 3.2 times larger bending actuation. The developed bio‐inspired soft actuator is a good candidate for satisfying the tight requirements of next generation soft electronic devices due to its key benefits such as low operating voltage and comparatively large strains, as well as quick response and facile processability.     

Synthetic Asymmetric‐Shaped Nanodevices with Symmetric pH‐Gating Characteristics

Synthetic stimuli‐gated nanodevices displaying intelligent ion transport properties similar to those observed in biological ion channels have attracted increasing interests for their wide potential applications in biosensors, nanofluidics, and energy conversions. Here, bioinspired asymmetric shaped nanodevices are reported that can exhibit symmetric and linear pH‐gating ion transport features based on polyelectrolyte‐asymmetric‐functionalized asymmetric hourglass‐shaped nanochannels. The pH‐responsive polymer brushes grafted on the inner channel surface are acted as a gate that open and close in response to external pH changing to linearly and symmetrically regulate transmembrane ionic currents of the channel. A complete experimental characterization of the pH‐dependent ion transport behaviors of the nanodevice and a comprehensive discussion of the experimental results in terms of theoretical simulation are also presented. Both experimental and theoretical data shown in this work demonstrate the feasibility of using the asymmetric chemical modification method to achieve symmetric pH gating behaviors inside the asymmetric nanochannels, and lay the foundation to build diverse stimuli‐gated artificial asymmetric shaped ion channels with symmetric gating ion transport features.     

Organic/Inorganic Hybrid Nanochannels Based on Polypyrrole‐Embedded Alumina Nanopore Arrays: pH‐ and Light‐Modulated Ion Transport

Inspired by the asymmetric structure and responsive ion transport in biological ion channels, organic/inorganic hybrid artificial nanochannels exhibiting pH‐modulated ion rectification and light‐regulated ion flux have been constructed by introducing conductive polymer into porous nanochannels. The hybrid nanochannels are achieved by partially modifying alumina (Al₂O₃) nanopore arrays with polypyrrole (PPy) layer using electrochemical polymerization, which results in an asymmetric component distribution. The protonation and deprotonation of Al₂O₃ and PPy upon pH variation break the surface charge continuity, which contributes to the pH‐tunable ion rectification. The ionic current rectification ratio is affected substantially by the pH value of electrolyte and the pore size of nanochannels. Furthermore, the holes (positive charges) in PPy layer induced by the cooperative effect of light and protons are used to regulate the ionic flux through the nanochannels, which results in a light‐responsive ion current. The magnitude of responsive ionic current could be amplified by optimizing this cooperation. This new type of stimuli‐responsive PPy/Al₂O₃ hybrid nanochannels features advantages of unique optical and electric properties from conducting PPy and high mechanical performance from porous Al₂O₃ membrane, which provide a platform for creating smart nanochannels system.     

Engineered Smart Gating Nanochannels for High Performance in Formaldehyde Detection and Removal

Bioinspired nanochannels for smart mass transport control have shown great potential for various applications in nanofluids, biosensing, and separation. Here, a nanochannel‐based smart responsive platform exhibiting high formaldehyde (HCHO) sensitivity is designed and successfully fabricated by functionalizing the inner pore surface with ethylenediamine (EDA). By employing the nucleophilic addition reaction between HCHO and EDA immobilized on the nanochannels, the artificial nanochannels can switch from an open state to a closed state with the increase in HCHO. This is because the surface charge density and the wettability of the nanochannels change along with the HCHO immobilization. Meanwhile, the EDA‐functionalized platform can hold a large amount of HCHO due to the abundant nanochannels of the membrane, so it presents a significant ability to remove HCHO in complex matrices. Also, the cultivation of mesenchymal stem cells in media containing HCHO can achieve excellent vitality in the presence of the EDA‐functionalized nanochannels materials. This work paves an avenue for designing and developing bioinspired nanochannel based platform for harmful compounds detection and removal.     

Multi-Control of Ion Transport in a Field-Effect Iontronic Device based on Sandwich-Structured Nanochannels

Biomimetic smart nanochannels can regulate ion transport behavior responsive to the external stimuli, having huge potential in nanofluidic devices, sensors and energy conversion. Field-effect nanofluidic diodes or transistors based on electric-responsive nanochannels are emerging owing to their advantages such as non-invasiveness, in situ, real time, and high efficiency. However, simultaneously realizing the voltage-control of the ion conductance and ion current rectification (ICR) properties is still a big challenge. Here, a field-effect iontronic device is developed based on ionomer/anodic aluminum oxide/conducting polymer sandwich-structured nanochannel to realize the multi-control of ion transport behaviors including ion conductance, ICR magnitude, and ICR direction by modulating the surface charge, wettability, and morphology of the nanochannel. The electroactive conducting polymer carries tunable surface charges responsive to the electric stimuli, leading to the regulation of ICR values. The complex three-segment structures lead to the reverse of ICR direction by reconfiguring the charge distribution along with the whole channel. The switching wettability between hydrophilic and hydrophobic results in the regulation of ion conductance. Furthermore, the field-effect iontronic device functions in a wide salinity range especially in hypersaline environment, due to the salinity-adaptive properties of the membrane. A new route is provided for designing more functional field-effect nanofluidic devices.     

A Photon‐Fueled Gate‐Like Delivery System Using i‐Motif DNA Functionalized Mesoporous Silica Nanoparticles

A novel photon‐fueled gate‐like mesoporous silica nanoparticles (MSN)‐based delivery system is reported. In this system, the malachite green carbinol base (MGCB) is immobilized on the nanochannel wall of MSN as a light‐induced hydroxide ion emitter and i‐motif DNA is grafted on the surface of MSN as a cap. Photoirradiation with 365 nm wavelength UV light makes MGCB molecules dissociate into malachite green (MG) cations and OH^? ions, which induce the i‐motif DNA to unfold into the single‐stranded form due to the increase of the pH in the solution. Therefore, the pores are uncapped and the entrapped guest molecules are released. After the light is turned off, the MG cations recombine with the OH^? ions and return to the MGCB forms. The pH value thus decreases and the single‐stranded DNA switches back to i‐motif structure to cap the pore again. Because of the photon‐fueled MGCB‐dependent DNA conformation changes, the i‐motif DNA‐gated switch can be easily operated by turning the light on or off. Importantly, the opening/closing protocol is highly reversible and a partial cargo release can be easily achieved at will. This proof‐of‐concept may promote the application of DNA in the controlled release and can also provide a way to design various photon‐fueled controlled‐release systems using a combination of some photoirradiated pH‐jump systems and other kinds of pH‐sensitive linkers.     

DNA‐Au Nanomachine Equipped with i‐Motif and G‐Quadruplex for Triple Combinatorial Anti‐Tumor Therapy

In the present study, the design, construction, and operation of a functional DNA‐decorated dynamic gold (Au) nanomachine as a therapeutic agent for triple combinatorial anti‐cancer therapy are revealed. Taking advantage of the intrinsic optical properties of Au nanoparticles, which depend on their size, a cytosine rich i‐motif sequence is employed for intracellular pH‐sensitive duplex dissociation and subsequent aggregation of the DNA‐Au nanomachine, enabling anticancer drug release and photothermal ablation upon irradiation with infrared light. Moreover, another functional DNA sequence, a G‐quadruplex, is exploited for the stable loading and intracellular delivery of a photosensitizer to achieve effective photodynamic therapy under red light illumination. The G‐quadruplex‐assisted enhanced reactive oxygen species generation, pH‐responsive dynamic aggregation behavior, consequent drug release, and the photothermal effect are investigated. Furthermore, the combinatorial chemo, photodynamic, and photothermal therapeutic effects of the functional DNA‐decorated Au nanomachines are evaluated in vitro and in vivo using a triple negative breast cancer model.     

Tumor Microenvironment Responsive Drug‐Dye‐Peptide Nanoassembly for Enhanced Tumor‐Targeting,Penetration, and Photo‐Chemo‐Immunotherapy

Nanomedicine constructed by therapeutics has unique and irreplaceable advantages in biomedical applications, especially in drug delivery for cancer therapy. The strategy, however, used to construct the therapeutics‐based nanomedicines with tumor microenvironmental factor responsiveness is still sophisticated. In this study, an easy‐operating procedure is used to construct a therapeutics‐based nanosystem with active tumor‐targeting, enhanced penetration, and stimuli‐responsive drug release behavior as well as programmed cell death‐1/programmed cell death‐ligand 1 (PD‐1/PD‐L1) blockading mediated immunomodulation to enhance tumor immunotherapy. The matrix metalloproteinase‐2 responsive peptide with the existence of Lyp‐1 sequence contributes to the success of active tumor‐targeting and the enhancement of the penetration of the nanoparticles in tumor tissue. The obtained nanosystem strikingly inhibits the primary tumor growth in the first 24 h (more than 97.5% of tumor cells are inhibited), and total inhibition can be achieved with the combination of photothermal therapy. IR820, which is served as the carrier for the therapeutics, is used as a photosensitizer for photothermal therapy. The progress and aggression of distal tumor has further been alleviated by a d ‐peptide which is an antagonist for PD‐1/PD‐L1 blockage. Therefore, a therapeutics‐constructed multifunctional nanosystem is provided to realize a combinational therapeutic strategy to enhance the therapeutic outcome.     

Long‐Term Oxygen Storage Nanosystem for Near‐Infrared Light‐Triggered Oxygen Supplies to Antagonize Hypoxia‐Induced Therapeutic Resistance in Nasopharyngeal Carcinoma

O₂‐delivering nanosystems have been used to antagonize hypoxia‐induced tumor therapeutic resistance. However, short‐time oxygen storage is still a bottleneck for these O₂‐delivering nanosystems, which results in a decrease in blood circulation time and accumulation of oxygen in tumors, thus reducing the tumor therapeutic efficacy. Herein, a long‐term oxygen storage nanosystem (O₂‐PIr@Si@PDA) is designed to overcome hypoxia for the treatment of nasopharyngeal carcinoma. This nanosystem is constructed by using perfluorooctyl bromide (PFOB) core as the oxygen carrier, functionalized with an oxygen sensitive probe (Ir(III) complex) and subsequently enclosed with an ultrathin‐walled silica shell. Due to the silica shell, this nanosystem can store oxygen for longer than 7 days. The oxygen in the O₂‐PIr@Si@PDA nanosystem can be released quickly with the temperature‐responsive rupture of the silicon shell under near‐infrared (NIR) irradiation. The oxygen storage and release can be self‐monitored using the Ir(III) complex with its luminescence effect. As expected, this multifunctional nanosystem in combination with NIR irradiation not only inhibits tumor growth by alleviating hypoxia, but also enhances the effect of oxygen‐sensitized radiotherapy against nasopharyngeal carcinoma. Taken together, this study offers a novel strategy for designing long‐term oxygen storing nanosystem to relieve tumor hypoxia, thus improving the precise cancer therapeutic efficacy.     

Tunable Nanochannels along Graphene Oxide/Polymer Core–Shell Nanosheets to Enhance Proton Conductivity

Simultaneous manipulation of topological and chemical structures to induce ionic nanochannel formation within solid electrolytes is a crucial but challenging task for the rational design of high‐performance electrochemical devices including proton exchange membrane fuel cell. Herein, a novel generic approach is presented for the construction of tunable ion‐conducting nanochannels via direct assembly of graphene oxide (GO)/poly(phosphonic acid) core–shell nanosheets prepared by surface‐initiated precipitation polymerization. Using this simple and rapid approach to engineer GO/polymer nanosheets at the molecular‐level, ordered and continuous nanochannels with interconnected hydrogen‐bonded networks having a favorable water environment can be created. The resulting membranes exhibit proton conductivities up to 32 mS cm^?1 at 51% relative humidity, surpassing state‐of‐the‐art Nafion membrane and all previously reported GO‐based materials.     

Bio‐Inspired Nanospiky Metal Particles Enable Thin,Flexible, and Thermo‐Responsive Polymer Nanocomposites for Thermal Regulation

Safety issues remain a major obstacle toward large‐scale applications of high‐energy lithium‐ion batteries. Embedding thermo‐responsive polymer switching materials (TRPS) into batteries is a potential strategy to prevent thermal runaway, which is a major cause of battery failures. Here, thin, flexible, highly responsive polymer nanocomposites enabled by bio‐inspired nanospiky metal (Ni) particles are reported. These unique Ni particles are synthesized by a simple aqueous reaction at gram‐scale with controlled surface morphology and composition to optimize electrical properties of the nanocomposites. The Ni particles provide TRPS films with a high room‐temperature conductivity of up to 300 S cm^?1. Such TRPS composite films also have a high rate (<1 s) of resistance switching within a narrow temperature range, good reversibility upon on/off switching, and a tunable switching temperature (T_s; 75 to 170 °C) that can be achieved by tailing their compositions. The small size (≈500 nm) of Ni particles enables ready fabrication of thin and flexible TPRS films with thickness approaching 5 µm or less. These features suggest the great potential of using this new type of responsive polymer composite for more effective battery thermal regulation without sacrificing cell performance.     

Multifunctional Graphene Oxide‐based Triple Stimuli‐Responsive Nanotheranostics

Construction of multifunctional stimuli‐responsive nanosystems intelligently responsive to inner physiological and/or external irradiations based on nanobiotechnology can enable the on‐demand drug release and improved diagnostic imaging to mitigate the side‐effects of anticancer drugs and enhance the diagnostic/therapeutic outcome simultaneously. Here, a triple‐functional stimuli‐responsive nanosystem based on the co‐integration of superparamagnetic Fe₃O₄ and paramagnetic MnO_x nanoparticles (NPs) onto exfoliated graphene oxide (GO) nanosheets by a novel and efficient double redox strategy (DRS) is reported. Aromatic anticancer drug molecules can interact with GO nanosheets through supramolecular π stacking to achieve high drug loading capacity and pH‐responsive drug releasing performance. The integrated MnO_x NPs can disintegrate in mild acidic and reduction environment to realize the highly efficient pH‐responsive and reduction‐triggered T₁‐weighted magnetic resonance imaging (MRI). Superparamagnetic Fe₃O₄ NPs can not only function as the T₂‐weighted contrast agents for MRI, but also response to the external magnetic field for magnetic hyperthermia against cancer. Importantly, the constructed biocompatible GO‐based nanoplatform can inhibit the metastasis of cancer cells by downregulating the expression of metastasis‐related proteins, and anticancer drug‐loaded carrier can significantly reverse the multidrug resistance (MDR) of cancer cells.     

Light‐Gating Titania/Alumina Heterogeneous Nanochannels with Regulatable Ion Rectification Characteristic

Bioinspired artificial nanochannels exhibiting ion transport properties similar to biological ion channels have been attracting some attention for biosensors, separation technologies, and nanofluidic diodes. Herein, an easily available artificial heterogeneous nanochannel shows both ion gating and ion rectification characteristics when irradiated by ultraviolet light. The fabrication of heterogeneous nanochannels includes the coating of an anatase TiO₂ porous layer on an alumina porous supporter, followed by a chemical modification with octadecyltrimethoxysilane (OTS) molecules. The irreversible decomposition of OTS molecules by TiO₂ photocatalysis under ultraviolet light results in a change of surface wettability and an asymmetric distribution of surface negative charges simultaneously, which contributes to the ion gating and ion rectification. The asymmetric distribution of negative charges in the TiO₂ porous layer can be controlled by the irradiation time of ultraviolet light, which regulates the ion rectification characteristic.     

Ionotronics Based on Horizontally Aligned Carbon Nanotubes

Controlled ion transport through ion channels of cell membranes regulates signal transduction processes in biological systems and has also inspired the thriving development of ionic electronics (ionotronics or iontronics) and biocomputing. However, for constructing highly integrated ionic electronic circuits, the integration of natural membrane‐spanning ion channel proteins or artificial nanomembrane‐based ionic diodes into planar chips is still challenging due to the vertically arranged architecture of conventional nanomembrane‐based artificial ionic diodes. Here, a new design of ionic diode is reported, which allows chip‐scale integration of ionotronics, based on horizontally aligned nanochannels made from multiwalled carbon nanotubes (MWCNTs). The rectification of ion transport through the MWCNT nanochannels is enabled by decoration of oppositely charged polyelectrolytes on the channel entrances. Advanced ionic electronic circuits including ionic logic gates, ionic current rectifiers, and ionic bipolar junction transistors (IBJT) are demonstrated on planar nanofluidic chips by stacking a series of ionic diodes fabricated from the same bundles of MWCNTs. The horizontal arrangement and facile chip‐scale fabrication of the MWCNT ionic diodes may enable new designs of complex but monolithic ionotronic systems. The MWCNT ionic diode may also prove to be an excellent platform for investigation of electrokinetic ion transport in 1D carbon materials.     

Positively K+‐Responsive Membranes with Functional Gates Driven by Host–Guest Molecular Recognition

A novel positively K⁺‐responsive membrane with functional gates driven by host‐guest molecular recognition is prepared by grafting poly(N‐isopropylacrylamide‐co‐acryloylamidobenzo‐15‐crown‐5) (poly(NIPAM‐co‐AAB₁₅C₅)) copolymer chains in the pores of porous nylon‐6 membranes with a two‐step method combining plasma‐induced pore‐filling grafting polymerization and chemical modification. Due to the cooperative interaction of host‐guest complexation and phase transition of the poly(NIPAM‐co‐AAB₁₅C₅), the grafted gates in the membrane pores could spontaneously switch from “closed” state to “open” state by recognizing K⁺ ions in the environment and vice versa; while other ions (e.g., Na⁺, Ca²⁺ or Mg²⁺) can not trigger such an ion‐responsive switching function. The positively K⁺‐responsive gating action of the membrane is rapid, reversible, and reproducible. The proposed K⁺‐responsive gating membrane provide a new mode of behavior for ion‐recognizable “smart” or “intelligent” membrane actuators, which is highly attractive for controlled release, chemical/biomedical separations, tissue engineering, sensors, etc.     

A Universal,Label‐Free,and Sensitive Optical Enzyme‐Sensing System for Nuclease and Methyltransferase Activity Based on Light Scattering of Carbon Nanotubes

A label‐free, enzyme‐responsive nanosystem that uses a DNA/single‐walled carbon nanotube (SWNT) assembly as the substrate is demonstrated for the sensitive, universal detection of restriction and nonrestriction endonucleases as well as methyltransferases in a homogeneous solution on the basis of light scattering (LS) of carbon nanotubes. This protocol is based on the different binding affinities of SWNTs to single‐ and double‐stranded DNA. This difference can lead to different LS signals that can be used for the detection of nuclease cleavage activity. The assay only requires a label‐free oligonucleotide probe, significantly reducing the typical cost. The LS technique and the use of a nuclease‐specific oligonucleotide probe impart extraordinarily high sensitivity and selectivity. This light scattering assay is universal and label‐free with a detection limit of 5 × 10^?6 U μL^?1 for S1 nuclease, 1 × 10^?4 U μL^?1 for EcoRI endonuclease, and 1 × 10^?2 U μL^?1 for EcoRI methylase. In principle, this assay can be used to detect any kind of nuclease by simply changing the DNA sequences of the specific probe.     

Stimuli‐Responsive Donor–Acceptor and DNA‐Crosslinked Hydrogels: Application as Shape‐Memory and Self‐Healing Materials

Carboxymethyl cellulose (CMC) chains are functionalized with self‐complementary nucleic acid tethers and electron donor or electron acceptor functionalities. The polymer chains crosslinked by the self‐complementary duplex nucleic acids and the donor–acceptor complexes as bridging units, yield a stiff stimuli‐responsive hydrogel. Upon the oxidation of the electron donor units, the donor–acceptor bridging units are separated, leading to a hydrogel of lower stiffness. By the cyclic oxidation and reduction of the donor units, the hydrogel is reversibly transformed across low and high stiffness states. The controlled stiffness properties of the hydrogel are used to develop shape‐memory hydrogels. In addition, CMC hydrogels crosslinked by donor–acceptor complexes and K⁺‐stabilized G‐quadruplexes reveal stimuli‐responsive properties that exhibit dually triggered stiffness functions. While the hydrogel bridged by the two crosslinking motifs reveals high stiffness, the redox‐stimulated separation of the donor–acceptor complexes or the crown‐ether‐stimulated separation of the G‐quadruplex bridges yields two alternative hydrogels exhibiting low stiffness states. The control over the stiffness properties of the dually triggered hydrogel is used to develop shape‐memory hydrogels, where the donor–acceptor units or G‐quadruplex bridges act as “memories”, and to develop triggered self‐healing process of the hydrogel.     

Stimuli‐Responsive DNA‐Gated Nanoscale Porous Carbon Derived from ZIF‐8

Stimuli‐responsive nanoscale porous carbon derived from ZIF‐8 (NCZIF) gated by DNA capping units is reported. The NCZIF is first obtained by calcination of nano‐ZIF‐8 crystals under an inert atmosphere. It is further conjugated with amine‐modified single‐stranded DNA after carboxylation (DNA/NCZIF). The guest molecules are sealed in the pore of NCZIF by the formation of a DNA duplex structure on the surface of NCZIF. As proof of principle, two systems that can be, respectively, used for controlled drug delivery and biosensing are introduced. In the first system, the drug model (rhodamine 6G, Rh6G) is locked in the NCZIF by the DNA capping units composed of rich‐G sequences and its complementary DNA strand. The in vitro cellular experiments reveal that DNA/NCZIF has good biocompatibility and can controllably release Rh6G upon the K⁺‐stimuli in cells. In the second system, the signal probe (methylene blue, MB) is locked in the NCZIF and then released after the unlocking of the pores triggered by the dissociation of the aptamer‐hybrid capping units. The MB‐loaded DNA/NCZIF can linearly respond to target molecules in the range from 1 × 10^?9 to 10 × 10^?6 m and has good specificity.