Adjusting the Linear Range of Au-MOF Fluorescent Probes for Real-Time Analyzing Intracellular GSH in Living Cells

Metal-organic frameworks as candidates for tumor sonodynamic therapy: Designable structures for targeted multifunctional transformation

Sonodynamic therapy (SDT), utilizing ultrasound (US) as the trigger, has gained popularity recently as a therapeutic approach with significant potential for treating various diseases. Metal-organic frameworks (MOFs), characterized by structural flexibility, are prominently emerging in the SDT realm as an innovative type of sonosensitizer, offering functional tunability and biocompatibility. However, due to the inherent limitations of MOFs, such as low reactivity to reactive oxygen species and challenges posed by the complex tumor microenvironment, MOF-based sonosensitizers with singular functions are unable to demonstrate the desired therapeutic efficacy and may pose risks of toxicity, limiting their biological applications to superficial tissues. MOFs generally possess distinctive crystalline structures and properties, and their controlled coordination environments provide a flexible platform for exploring structure-effect relationships and guiding the design and development of MOF-based nanomaterials to unlock their broader potential in biological fields. The primary focus of this paper is to summarize cases involving the modification of different MOF materials and the innovative strategies developed for various complex conditions. The paper outlines the diverse application areas of functionalized MOF-based sonosensitizers in tumor synergistic therapies, highlighting the extensive prospects of SDT. Additionally, challenges confronting SDT are briefly summarized to stimulate increased scientific interest in the practical application of MOFs and the successful clinical translation of SDT. Through these discussions, we strive to foster advancements that lead to early-stage clinical benefits for patients. STATEMENT OF SIGNIFICANCE: 1. An overview for the progresses in SDT explored from a novel and fundamental perspective. 2. Different modification strategies to improve the MOFs-mediated SDT efficacy are provided. 3. Guidelines for the design of multifunctional MOFs-based sonosensitizers are offered. 4. Powerful tumor ablation potential is reflected in SDT-led synergistic therapies. 5. Future challenges in the field of MOFs-based SDT in clinical translation are suggested.

Covalent organic framework-MnO2 nanoparticle composites for shape-selective sensing of bithiols

Covalent organic frameworks (COFs) for detecting biological macromolecules in water or biological environments are generally challenging. In this work, a composite material IEP-MnO₂ is obtained by combining manganese dioxide (MnO₂) nanocrystals and a fluorescent COF (IEP), which is synthesized by using 2,4,6-tris(4-aminophenyl)-s-triazine and 2,5-dimethoxyterephthalaldehyde. By the addition of biothiols, such as glutathione, cysteine or homocysteine with different sizes, the fluorescence emission spectra of IEP-MnO₂ changed ("turn-on" or "turn-off") via different mechanisms. The fluorescence emission of IEP-MnO₂ increased in the presence of GSH by the elimination of the FRET (Förster resonance energy transfer) effect between MnO₂ and IEP. Surprisingly, due to the formation of a hydrogen bond between Cys/Hcy and IEP, the fluorescence quenching for IEP-MnO₂ + Cys/Hcy may be explained via the photoelectron transfer (PET) process, which endows IEP-MnO₂ with specificity in distinguishing the detection of GSH and Cys/Hcy compared to other MnO₂ complex materials. Therefore, IEP-MnO₂ was used to detect GSH and Cys in human whole blood and serum, respectively. The limit of detection for GSH in whole blood and Cys in human serum was calculated to be 25.58 μM and 4.43 μM, which indicates that IEP-MnO₂ can be used to investigate some diseases related to GSH and Cys concentration. Moreover, the research expands the application of covalent organic frameworks in the fluorescence sensing field.

In-situ bio-assembled specific Au NCs-Aptamer-Pyro conjugates nanoprobe for tumor imaging and mitochondria-targeted photodynamic therapy

Mitochondrion has emerged as a promising drug target for photodynamic therapy (PDT), due to its significant role in supporting life activities and being reactive oxygen species (ROS)-sensitive. Herein, we establish a new strategy that in-situ bio-synthesized Au NCs combine with mitochondria-targeted aptamer-Pyro conjugates (ApPCs) for specific tumor imaging and PDT. The prepared ApPCs can serve as template for the in-situ bio-synthesis of Au NCs, thereby facilitating the generation of Au NCs-ApPCs assemblies in unique tumor microenvironment. Compared with highly negatively charged ApPCs, bio-synthesized nanoscale Au NCs-ApPCs assemblies are conducive to cell uptake, which consequently benefits the delivery of ApPCs. After dissociated from Au NCs-ApPCs, internalized ApPCs can selectively accumulate in mitochondria and generate excess ROS to disrupt the mitochondrial membrane upon irradiation, thus inducing efficient cell killing. In vitro assays demonstrated that the fluorescent Au NCs-ApPCs assemblies could be specifically produced in cancerous cells, indicating the specific tumor imaging ability, while intracellular ApPCs co-localized well with mitochondria. CCK-8 results revealed over 80% cell death after PDT. In vivo study showed that fluorescent Au NCs-ApPCs assemblies were exclusively generated in tumor and achieved long-term retention; tumor growth was significantly inhibited after 15-day PDT treatment. All these evidences suggest that in-situ bio-synthesized Au NCs-ApPCs assembly is a potent mitochondria-targeted nanoprobe to boost the PDT efficacy of cancers.

How to get maximum structure information from anisotropic displacement parameters obtained by three-dimensional electron diffraction: an experimental study on metal-organic frameworks

Three-dimensional electron diffraction (3D ED) has been used for ab initio structure determination of various types of nanocrystals, such as metal-organic frameworks (MOFs), zeolites, metal oxides and organic crystals. These crystals are often obtained as polycrystalline powders, which are too small for single-crystal X-ray diffraction (SCXRD). While it is now possible to obtain accurate atomic positions of nanocrystals by adopting kinematical refinement against 3D ED data, most new structures are refined with isotropic displacement parameters (U _eq), which limits the detection of possible structure disorders and atomic motions. Anisotropic displacement parameters (ADPs, U^ij ) obtained by anisotropic structure refinement, on the other hand, provide information about the average displacements of atoms from their mean positions in a crystal, which can provide insights with respect to displacive disorder and flexibility. Although ADPs have been obtained from some 3D ED studies of MOFs, they are seldom mentioned or discussed in detail. We report here a detailed study and interpretation of structure models refined anisotropically against 3D ED data. Three MOF samples with different structural complexity and symmetry, namely ZIF-EC1, MIL-140C and Ga(OH)(1,4-ndc) (1,4-ndcH₂ is naphthalene-1,4-dicarboxylic acid), were chosen for the studies. We compare the ADPs refined against individual data sets and how they are affected by different data-merging strategies. Based on our results and analysis, we propose strategies for obtaining accurate structure models with interpretable ADPs based on kinematical refinement against 3D ED data. The ADPs of the obtained structure models provide clear and unambiguous information about linker motions in the MOFs.

Silver nanoparticles combined with amino-functionalized UiO-66 for sensitive detection of glutathione

Herein, a fluorescent nanosensor has been constructed for detection of glutathione (GSH) based on NH₂-UiO-66 and AgNPs. The NH₂-UiO-66 was synthesized where 2-amino-terephthalic acid as the organic ligand and Zr⁴⁺ as the center metal ions. The AgNPs can enhance the fluorescence of NH₂-UiO-66 based on metal enhanced fluorescence (MEF) effect. Moreover, in the present of GSH, the fluorescence of NH₂-UiO-66@AgNPs was quenched via electrostatic interaction and Ag-S reaction. The present sensing strategy shows good linear relation with the concentration of GSH in the range of 0.2-1.0 μM and 1.0-30 μM, and the limit of detection is 79 nM. Furthermore, our fluorescent nanosensor was utilized to detect GSH in human serum with a recovery of 96.8-102.5%. The results indicated that NH₂-UiO-66@AgNPs is successfully applied for high sensitive and selective detection of GSH in human serum.

A sensitive fluorescence "turn on" nanosensor for glutathione detection based on Ce-MOF and gold nanoparticles

Glutathione (GSH) as an essential biothiol maintains redox homeostasis in human body, the aberrant level of it has been related to various diseases. In this work, we constructed a facile and environment-friendly strategy by using Ce based metal-organic frameworks and gold nanoparticles (AuNPs) for detection of GSH. The fluorescence intensity of the Ce-MOF was quenched by AuNPs, which is ascribed to the existence of fluorescence resonance energy transfer (FRET) and electrostatic interaction between Ce-MOFs and AuNPS. Because of the formation of Au-SH between AuNPs and GSH, the addition GSH induced the Ce-MOF/AuNPs and prevented the occurrence of FRET and electrostatic interaction between Ce-MOFs and AuNPS, which futher recovered the fluorescence of Ce-MOF. Under the optimized conditions, this "turn-on" sensing process revealed a high selectivity toward GSH and displayed good linearity in range of 0.2-32.5 μM with low detection limit of 58 nM. In addition, the practicability of the strategy was testified through analyzing GSH in real human serum samples.

Fluorescence-Raman dual-mode quantitative detection and imaging of small-molecule thiols in cell apoptosis with DNA-modified gold nanoflowers

The monitoring of small-molecule thiols (especially glutathione) has attracted widespread attention due to their involvement in numerous physiological processes in living organisms and cells. In this work, a dual-mode nanosensor was designed to detect small-molecule thiols, which is based on the "on-off" switch of fluorescence resonance energy transfer (FRET) and surface-enhanced Raman scattering (SERS). Briefly, DNA was modified by Cy5 (signal probe) and disulfide bonds (recognition element). Gold nanoflowers (AuNFs) were used as the fluorescence-quenching and SERS-enhancing substrate. However, small-molecule thiols can cleave disulfide bonds and release short Cy5-labeled chains, causing the recovery of the fluorescence signal and a decrease of the SERS signal. The nanosensor showed a sensitive response to small-molecule thiols represented by GSH, with a linear range of 0.01-3 mM and a detection limit of 913 nM. In addition, it competed with other related biological interferences and presented good stability and better selectivity towards small-molecule thiols. Most importantly, the developed nanosensor had been successfully applied to in situ imaging and quantitative monitoring of the concentration of small-molecule thiols which changed during T-2 toxin-induced apoptosis in HeLa cells. Meanwhile, nanosensors are also versatile with their potential applications and can be easily extended to the detection and imaging of other human cell lines. The proposed method combines the dual advantages of fluorescence and SERS, which has broad prospects for in situ studies of physiological processes involving small-molecule thiols in biological systems.

19F NMR Allows to Investigate the Fate of Platinum(IV) Prodrugs in Physiological Conditions

Pt(IV) prodrugs can overcome resistance and side effects of conventional Pt(II) anticancer therapies. By 19 F-labeling of a Pt(IV) prodrug (Pt-FBA, FBA = p -fluorobenzoate), the activation under physiological conditions could be investigated. It is found that, unlike single-electron reductants, multi-electron agents can efficiently promote the two electrons reduction of Pt(IV) to Pt(II). Moreover, the activation of Pt-FBA in cell lysate is highly dependent upon the type of cancer cells. When administered to E. coli , Pt-FBA is reduced intracellularly and free FBA can shuttle out of the cell. Interestingly, the reduction rate greatly increases by inducing metallothionein overexpression and is lowered by addition of Zn(II) ions. Finally, when injected into mice, Pt-FBA undergoes fast reduction in the bloodstream accompanied by metabolic degradation of FBA; nevertheless, unreduced Pt-FBA can accumulate to detectable levels in liver and kidneys. The proposed 19 F-NMR approach has the advantage of avoiding the interference of all background signals.

Design of a ratiometric fluorescence sensor based on metal organic frameworks and Ru(bpy)32+-doped silica composites for 17β-Estradiol detection

17β-Estradiol (E2), an important endocrine disrupting compound, could be quantitatively detected by fluorescence resonance energy transfer (FRET) aptasensor, designed in this paper. Metal organic frameworks have large specific surface area and easily modifiable groups, which are helpful for the construction of aptasensor. Specifically, streptavidin was immobilized on the synthesized MIL-53-NH₂ by covalent bonding, and further linked with the biotin modified E2 aptamer (apt) through specific bonding between avidin and biotin to obtain the FRET donor probe (MIL-53-apt). Meanwhile, complementary DNA (cDNA) modified Ru(bpy)₃²⁺-doped silica nanoparticles (RuSiO₂-cDNA) were prepared through covalent bonding. They acted as the FRET acceptor probe, since its absorption spectrum showed large overlap with the emission spectrum of MIL-53-apt. In the presence of E2, aptamer modified donor probes tended to bind with E2, owing to their higher selectivity and affinity. Therefore, the optimal distance between FRET pairs was broken, resulting in the fluorescence emission recovery of donor and the fluorescence emission of acceptor decreased. Under optimal conditions, this proposed aptasensor displayed sensitive detection of E2 ranging from 0.5 to 1000 nM with a detection limit of 0.2 nM. Furthermore, the sensor provides a promising method for rapid and sensitive detection of other small biological molecules.

Linker-Eliminated Nano Metal-Organic Framework Fluorescent Probe for Highly Selective and Sensitive Phosphate Ratiometric Detection in Water and Body Fluids

Phosphate is an important anion in both the aquatic environment and biological systems. The search for a selective and sensitive phosphate ratiometric fluorescent probe to quantify the phosphate level in water samples and body fluids is of great significance for the protection of the ecological environment and human health. Here, a porphyrin-based nano metal-organic framework (NMOF), PCN-224, was successfully exploited as a simple but highly sensitive and selective single-component ratiometric fluorescent probe with accurate composition and measurable structure for the quantitative determination of phosphate, based on the interesting double-emission fluorescence of the porphyrin ligand itself. Compared with other zirconium-based NMOF probes for phosphate, the reduced number of connections for ZrO clusters with the ligand in PCN-224 obtained by a linker-elimination strategy simultaneously provides more active recognition sites for phosphate, which effectively improves the sensitivity of the zirconium-based NMOF probes. The detection limit of the probe is only 54 nM. Additionally, the accuracy of the ratiometric detection based on this probe was further proved by the detection of phosphate in human serum and drinking water.

Application of Various Metal-Organic Frameworks (MOFs) as Catalysts for Air and Water Pollution Environmental Remediation

The use of metal-organic frameworks (MOFs) to solve problems, like environmental pollution, disease, and toxicity, has received more attention and led to the rapid development of nanotechnology. In this review, we discuss the basis of the metal-organic framework as well as its application by suggesting an alternative of the present problem as catalysts. In the case of filtration, we have developed a method for preparing the membrane by electrospinning while using an eco-friendly polymer. The MOFs were usable in the environmental part of catalytic activity and may provide a great material as a catalyst to other areas in the near future.

A white-light-emitting lanthanide metal–organic framework for luminescence turn-off sensing of MnO4− and turn-on sensing of folic acid and construction of a “turn-on plus” system

A white-light-emitting lanthanide MOF shows recyclable and dual-responsive sensing for MnO₄⁻ and folic acid in an aqueous system with high selectivity and sensitivity.

A visible and near-infrared dual-fluorescent probe for discrimination between Cys/Hcy and GSH and its application in bioimaging

The probe Cy2 showed high sensitivity and excellent selectivity with a distinct fluorescence off-on response to GSH with NIR emission and Cys/Hcy with green emission, respectively.

Endogenous Cys-Assisted GSH@AgNCs-rGO Nanoprobe for Real-Time Monitoring of Dynamic Change in GSH Levels Regulated by Natural Drug

Glutathione (GSH) levels are closely related to the homeostasis of redox state which directly affects human disease occurrence by regulating cell apoptosis. Hence, real-time monitoring of dynamic changes in intracellular GSH levels is urgently needed for disease early diagnosis and evaluation of therapy efficiency. In this study, an endogenous cysteine (Cys)-assisted detection system based on GSH@AgNCs and reduced graphene oxide (rGO) with high sensitivity and specificity was developed for GSH detection. Compared with GSH, GSH@AgNCs with weaker affinity and bonding force was quite easier to extrude from the rGO surface when competing against GSH, leading to the obvious change in fluorescence signal. This phenomenon was termed as "a crowding out effect". Furthermore, the presence of Cys can improve GSH assay sensitivity by enhancing the quenching efficiency of rGO on the GSH@AgNCs. In vitro assay indicated that the efficiency of fluorescence recovery was positively related with GSH concentration in the range from 0 to 10 mM. In addition, the method was employed for real-time monitoring of the dynamic changes in GSH levels regulated by natural drugs. The imaging results showed that the natural compound 3 (C3) can downregulate GSH levels in HepG2 cells, which was accompanied by reactive oxygen species (ROS) release and apoptosis induction. Finally, the method was used to monitor the change of GSH levels in serum samples with chronic hepatitis B (CHB) infection. The results demonstrated that the occurrence and development of CHB may be positively correlated with GSH levels to some extent. Overall, the above results demonstrate the potential application of this new nanosystem in anticancer natural drug screening and clinical assay regarding GSH levels.

Nonvolatile Electrical Bistability Behaviors Observed in Au/Ag Nanoparticle-Embedded MOFs and Switching Mechanisms

Electrically bistable devices play an important role in the next generation of information materials. Plasmonic noble metal nanoparticles (Au and Ag NPs) with diameters <6 nm were embedded into 3-D Cd-based metal-organic framework (MOF) matrixes via the photoreduction method to generate Au (Ag) NPs@MOF composites. Electrical bistability measurements on the sandwiched ITO/NPs@MOF/silver devices indicate that two switchable conductivity states with nonvolatile memory behaviors can be observed. The ITO/Au NP@2/Ag device with neutral matrix possesses the highest ON/OFF current ratio of 10⁴, which can be attributed to its higher electron tunneling efficiency because of the better dispersity of Au NPs in the MOF matrix. A mechanism regarding the electric-field-induced charge-transfer process assisted by conformational change in the active layer was proposed.

Intracellular Imaging of Glutathione with MnO2 Nanosheet@Ru(bpy)32+-UiO-66 Nanocomposites

Fluorescent detection of glutathione (GSH) in the living system has attracted much attention, but current fluorescent probes are usually exposed to the exterior environment, leading to photobleaching and premature leakage and subsequently limiting the sensitivity and photostability. Herein, luminescent metal-organic frameworks [Ru(bpy)₃²⁺ encapsulated in UiO-66] coated with manganese dioxide nanosheets [MnO₂ NS@Ru(bpy)₃²⁺-UiO-66] were prepared by an in situ growth method and further explored to construct a GSH-switched fluorescent sensing platform. Because of the splendid fluorescence quenching ability, special probe leakage blocking role and distinguished recognition of the MnO₂ NS, and the improved fluorescence of Ru(bpy)₃²⁺ by UiO-66, a low background, highly sensitive and selective detection of GSH with a low limit of detection as 0.28 μM was realized. At the same time, the preparation of MnO₂ NS@Ru(bpy)₃²⁺-UiO-66 nanocomposites is simple and less toxic, and there was no notable loss of cell survivability after being exposed to MnO₂ NS@Ru(bpy)₃²⁺-UiO-66 below the concentrations of 120 μg mL^-1 for 24 h. Consequently, the results coming from this effort suggest that the new sensing platform will have a great potential in the detection of GSH in living cells.

A Cd-MOF as a fluorescent probe for highly selective, sensitive and stable detection of antibiotics in water

Recently, the pollution and damage caused by antibiotics in water have aroused serious concerns. In this situation, it is extremely important to develop a highly effective approach to detect antibiotics in water. In this contribution, we built a Cd-MOF material with stable fluorescence properties, using bbi = 1,4-bis(2-methyl-imidazol-1-yl)butane and H2L = 1,2-phenylenediacetic acid as organic ligands and Cd(NO3)2·4H2O as the metal node. The highly selective response of this MOF probe to ceftriaxone sodium (an antibiotic) can reach up to the ppb level in water, along with a fast response time, acid and alkali resistance, and anti-interference ability.

Discriminative Detection of Glutathione in Cell Lysates Based on Oxidase-Like Activity of Magnetic Nanoporous Graphene

As the most abundant intracellular biothiol, glutathione (GSH) plays a central role in many cellular functions and has been proved to be associated with numerous clinical diseases. Nevertheless, it is still a challenge to detect GSH over other mercaptoamino acids owing to their similar structures and activities. In this paper, magnetic nanoporous graphene (MNPG) nanocomposites were prepared for the first time through partial combustion of graphene oxide (GO) and ferric chloride. Due to the combination of porous graphene and magnetic nanoparticles, the MNPG nanocomposites exhibited large specific surface area, fast mass, and electron transport kinetics, resulting in remarkable oxidase mimic activity and easy separation. On the basis of the inhibition effect of GSH on the MNPG-catalyzed oxidation of thiamine, a novel and simple method for fluorescence determination of GSH was established. The sensor displayed a good linear response in the range of 0.2-20 μM toward GSH with a limit of detection of 0.05 μM. High sensitivity and selectivity facilitated its practical application for discriminative detection of GSH levels in PC12 cell lysates. The presented assay will be a simple and powerful tool to monitor intracellular GSH levels for biomedical diagnosis. Furthermore, the MNPG nanocomposites will provide insights to construct nanoporous graphene-based hybrids and push forward the advancement of porous graphene for wide applications.

Biocompatible Au@Ag nanorod@ZIF-8 core-shell nanoparticles for surface-enhanced Raman scattering imaging and drug delivery

A surface-enhanced Raman scattering (SERS) imaging probe and drug carrier based on zeolitic imidazolate framework (ZIF-8)-coated Au@Ag core-shell nanorod has been developed. Strong Raman signal is generated by a reporter molecule of 4-aminothiophenol (4-ATP) adsorbed on Au@Ag core-shell nanorod, endowing the probe with function of SERS imaging. Further coating of ZIF-8 on Au@Ag core-shell nanorod offered high loading capacity for anti-cancer drugs, doxorubicin (DOX), as well as improved the stability and biocompatibility of the SERS tag due to the protection of ZIF-8 shell. After immobilization of folic acid onto the Au@Ag NRs^4-ATP@ZIF-8, the SERS probes were successfully applied to the targeted SERS imaging of HeLa, MCF-7, LNCaP, QGY-7703, HCT116 and MDA-MB-231 cells with low cytotoxicity, and further applied to the image of tumor tissue of human colon cancer. In vitro cell cytotoxicity confirmed that DOX-loaded SERS probes had potential therapeutic effect compared with the free drug. All of these original results contribute to develop potential biocompatible nanosystem integrating diagnosis and therapy.

Rotational Dynamics of Linkers in Metal⁻Organic Frameworks

Among the numerous fascinating properties of metal⁻organic frameworks (MOFs), their rotational dynamics is perhaps one of the most intriguing, with clear consequences for adsorption and separation of molecules, as well as for optical and mechanical properties. A closer look at the rotational mobility in MOF linkers reveals that it is not only a considerably widespread phenomenon, but also a fairly diverse one. Still, the impact of these dynamics is often understated. In this review, we address the various mechanisms of linker rotation reported in the growing collection of literature, followed by a highlight of the methods currently used in their study, and we conclude with the impacts that such dynamics have on existing and future applications.

Metal coordination-functionalized Au–Ag bimetal SERS nanoprobe for sensitive detection of glutathione

Neocuproine-Cu functionalized Au–Ag nanoparticles as nanoprobe for detection of glutathione based on the SERS spectra changing from Neocuproine-Cu^II to Neocuproine-Cu^I.

Ratiometric fluorescent nanosensors for ultra-sensitive detection of mercury ions based on AuNCs/MOFs

Ratiometric fluorescent nanosensors were developed to detect mercury ions (Hg²⁺) using enhanced dual emissions from glutathione stabilized gold nanoclusters/indium-based metal–organic frameworks modified with cysteine (AuNCs/MIL-68(In)-NH₂/Cys).

A metal–organic framework constructed by a viologen-derived ligand: photochromism and discernible detection of volatile amine vapors

A Co(ii)-MOF based on a viologen-derived ligand was obtained: the Co(ii) compound exhibits photochromism, and allows the visual and differentiable detection of different volatile alkylamines.

AuNPs-PCL nanocomposite accelerated abdominal wound healing through photothermal effect and improving cell adhesion

Accelerating wound healing with modified biomaterial has been an attracting field in both material science and medicine. Enhanced cell adhesion could be acquired by improving surface hydrophilicity, which contributes to accelerating wound healing. Chemical reaction has been used for surface modification, but this study used a simple and nontoxic method to improve the hydrophilicity. Polycaprolactone (PCL) scaffold has been regarded as promising material for wound healing while its surface is hydrophobic. Our study demonstrated enhanced hydrophilicity of PCL with AuNPs coating. AuNPs has good biocompatibility and excellent photothermal effect. The coating of AuNPs not only improved the cell adhesion, but also gave PCL the ability to inhibit the growth of bacteria. Animal study showed that the nanocomposites decreased lymphocytes and neutrophils, increased neovascularization and accelerated the abdominal wound healing, which was attributed to improved hydrophilicity and the antibacterial ability. In conclusion, we demonstrated that the nanocomposite could be used as a potential scaffold for cell adhesion and wound healing, and the role of AuNPs was highlighted as a kind of outstanding supplement.

GSH-Activated Light-Up Near-Infrared Fluorescent Probe with High Affinity to αvβ3 Integrin for Precise Early Tumor Identification

The development of tumor-associated, stimuli-driven, turn-on near-infrared (NIR) fluorophores requires urgent attention because of their potential in selective and precise tumor diagnosis. Herein, we describe a NIR fluorescent probe (CyA-cRGD) comprised of a fluorescence reporting unit (a cyanine dye) linked with a GSH-responsive unit (nitroazo aryl ether group) and a tumor-targeting unit (cRGD). The NIR fluorescence of CyA-cRGD with sensitive and selective response to GSH can act as a direct off-on signal reporter for GSH monitoring. Notably, CyA-cRGD possesses improved biocompatibility compared with CyA, which is highly desirable for in vivo fluorescence tracking of cancer. Confocal fluorescence imaging confirmed the tumor-targeting capability and GSH detection ability of CyA-cRGD in tumor cells, normal cells, and coincubated tumor /normal cells and in the three-dimensional multicellular tumor spheroid. Furthermore, it was validated that CyA-cRGD could detect tumor precisely in GSH and integrin α_vβ ₃ high-expressed tumor-bearing mouse models. Importantly, it was confirmed that CyA-cRGD possessed high efficiency for early-stage tumor imaging in mouse models with tumor cells implanted within 72 h. This method provided significant advances toward more in-depth understanding and exploration of tumor imaging, which may potentially be applied for clinical early tumor diagnosis.

Luminescent Hybrid Membrane-Based Logic Device: From Enantioselective Discrimination to Read-Only Memory for Information Processing

Logic circuit device and molecular computer are idealized binary tools that implement manifold signal transformation and operation and is a basic component of integrated circuits and is widely used in computer, computerized numerical control, and communication fields. By combining the advantages of synthetic feasibility and enantioselective luminescent recognition, a logic device based on the lanthanide functional membrane has been constructed to effectively recognize the enantiomer and judge the enantiomer excess of the chair drug mixture. In addition, it would be interesting if such a logic circuit could be assembled into a loop circuit to realize intelligent control of the electronic component. Read-only memory arrays built by the logic circuit are also actualized, which can be converted and stored in binary strings. This work provides an active and universal approach to modulate a luminescent device and logic circuit based on a chemical sensor, with promising application for intelligent control, information processing, and human-machine interaction.