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This study demonstrates that the therapeutic efficacy of inorganic nanomaterials can be optimized by employing different thermal treatment atmospheres.

Current therapeutic strategies for Alzheimer's disease (AD) mainly focus on inhibition of aberrant amyloid-β peptide (Aβ) aggregation. However, these strategies cannot repair the side symptoms (e.g., high neuronal oxidative stress) triggered by Aβ accumulation and thus show limited effects on suppressing Aβ-induced neuronal apoptosis. Herein, we develop a stepwise metal-phenolic coordination approach for the rational design of a neuroprotection enhancer, K8@Fe-Rh/Pda NPs, in which rhein and polydopamine are effectively coupled to enhance the treatment of AD in APPswe/PSEN1dE9 transgenic (APP/PS1) mice. We discover that the polydopamine inhibits the aggregation of Aβ oligomers, and rhein helps repair damage to neurons triggered by Aβ aggregation. Based on molecular docking, we demonstrate that the polydopamine has a strong interaction with Aβ monomers/fibrils through its multiple recognition sites (e.g., catechol groups, imine groups, and indolic/catecholic π-systems), thereby reducing Aβ burden. Further investigation of the antioxidant mechanisms suggests that K8@Fe-Rh/Pda NPs promote the mitochondrial biogenesis via activating the sirtuin 1 (SIRT1)/peroxisome proliferator-activated receptor gamma coactivator 1-alpha pathway. This finally inhibits neuronal apoptosis. Moreover, an intravenous injection of these nanoparticles potently improves the cognitive function in APP/PS1 mice without adverse effects. Overall, our work provides a promising approach to develop advanced nanomaterials for multi-target treatment of AD.

Antibacterial nanoagents with broad-spectrum antibacterial activities have emerged as an evolution of antibiotics. However, their bacteria-capturing capability and bacteria-killing efficiency remain insufficient for commercial implementation. Inspired by the hunting behavior of spiders, here, a novel spiderweb-like nanoagent based on silver-adenine nanowires is designed to achieve high-efficiency capture and killing of bacteria. By virtue of the initiative bacteria-capturing functionality, this spiderweb-like nanoagent could effectively attract and trap bacteria through electrostatic interaction and its reticular morphology feature. Furthermore, its synergetic antibacterial mechanism combining physical membranolysis with reactive oxygen species (ROS) release allows such nanoagent to harvest a promoted bactericidal activity. Importantly, the woundplast employing the spiderweb-like nanoagent exhibits a superior antibacterial efficacy against drug-resistant Gram-negative Escherichia coli and Gram-positive methicillin-resistant Staphylococcus aureus compared with commercially available woundplasts. This work may pave a new way for rational design of new generation bactericidal agents facing the future super-bacteria booming.

Mitochondria-targeted synergistic therapy, including photothermal (PTT) and photodynamic therapy (PDT), has aroused wide attention due to the high sensitivity to reactive oxygen species (ROS) and heat shock of mitochondria. However, most of the developed nanosystems for the combinatorial functions require the integration of different components, such as photosensitizers and mitochondria-targeted molecules. Consequently, it indispensably requires sophisticated design and complex synthetic procedures. In this work, a well-designed Bi2S3-based nanoneedle, that localizes to mitochondria and produces extra ROS with inherent photothermal effect, was reported by doping of Fe (denoted as FeBS). The engineered intrinsic characteristics certify the capacity of such "one-for-all" nanosystems without additional molecules. The lipophilicity and surface positive charge are demonstrated as crucial factors for specifical mitochondria targeting. Significantly, Fe doping overcomes the disadvantage of the narrow band gap of Bi2S3 to prevent the fast recombination of electron-hole, hence resulting in the generation of ROS for PDT. The "one-for-all" nanoparticles integrate with mitochondria-targeting and synergistic effect of PDT and PTT, thus exhibit enhanced therapeutic effect and inhibit the growth of tumors observably. This strategy may open a new direction in designing the mitochondria-targeted materials and broadening the properties of inorganic semiconductor materials for satisfactory therapeutic outcomes.

The antioxidant system of tumor cells severely impairs reactive oxygen species (ROS)-mediated tumor therapy. Despite extensive attempts to attenuate the antioxidant capacity by eliminating ROS scavengers such as glutathione (GSH), nicotinamide adenine dinucleotide phosphate (NADPH) over-expressed in the tumor microenvironment can regenerate GSH from glutathione disulfide (GSSG), hence weakening ROS-induced oxidative damage. Therefore, engineering a nanoplatform capable of depleting both NADPH and GSH is extremely significant for improving ROS-mediated tumor treatment. Herein, a synergetic antioxidant inhibition strategy is proposed to attenuate intracellular antioxidant capacity for hypoxic tumor therapy. In this context, both porous Prussian blue nanoparticles (PPB NPs) and cisplatin prodrug [cis-Pt (IV)] in the nanoplatform can oxidize GSH to directly reduce GSH levels, while PPB NPs also enable NADPH depletion by peroxidase-mimicking to impair GSH regeneration. Furthermore, PPB NPs with catalase-mimicking activity catalyze H

Mitigating cellular resistance, which could enhance the sensitivity of tumor cells to treatment, is a promising approach for obtaining better therapeutic outcomes. However, the present designs of materials generally disregard this point, or only focus on a single specific resistance. Herein, a strategy based on a series of cascade reactions aiming to suppress multiple cellular resistances is designed by integrating photothermal and chemotherapy into a mitochondria targeted nanosystem (AuBPs@TD). The intelligent nanosystem is fabricated by modifying gold nanobipyramids (AuBPs) with triphenylphosphonium (TPP) functionalized dichloroacetic acid (DCA). TPP serves as a "navigation system" and facilitates the location of AuBPs@TD in the mitochondria. Moreover, the released DCA promoted by the photothermal effect of AuBPs, as the mitochondrial kinase inhibitor, could inhibit glycolysis, and lead to a repressed expression of heat shock protein 90, which is the main resistance protein in cancer cells against photothermal therapy (PTT). Thus, the photothermal antitumor effect can be significantly improved. For the other cascade passage, the hyperthermal atmosphere depresses the expression of P-glycoprotein, a protein associated with drug resistance, and consequently prevents DCA molecules from being expelled in return. Furthermore, the retained DCA molecules elevate the concentration of intracellular hydrogen peroxide, and due to the peroxidase-like activity of AuBPs, increased intracellular reactive oxygen species could be obtained to accelerate apoptosis. As a result, these cascade reactions lead to significant inhibition of cellular resistance and greatly improve the therapeutic performance. This work paves a new way for suppressing cellular resistance to achieve the desired therapeutic effect.

Theranostic nanoprobes can potentially integrate imaging and therapeutic capabilities into a single platform, offering a new personalized cancer diagnostic tool. However, there is a growing concern that their clinical application is not safe, particularly due to metal-containing elements, such as the gadolinium used in magnetic resonance imaging (MRI). We demonstrate for the first time that the photothermal melting of the DNA duplex helix was a reliable and versatile strategy that enables the on-demand degradation of the gadolinium-containing MRI reporter gene from polydopamine (PDA)-based theranostic nanoprobes. The combination of chemotherapy (doxorubicin) and photothermal therapy, which leads to the enhanced anti-tumor effect. In vivo MRI tracking reveals that renal filtration was able to rapidly clear the free gadolinium-containing MRI reporter from the mice body. This results in a decrease in the long-term toxic effect of theranostic MRI nanoprobes. Our findings may pave the way to address toxicity issues of the theranostic nanoprobes.

Biosensors is an advanced detection and monitoring device for the development of biotechnology, and is also a rapid and microanalytical device at the molecular level. Demands for high sensitivity, high flexibility, good biocompatibility, easy chemical modification and low cost offer incentive for exploring new materials to develop the next-generation biosensors. With the vigorous development of organic electronics, the performances of organic devices have been effectively improved, leading to organic semiconductor materials with low cost, good flexibility, easy chemical modification and good biocompatibility for biosensors. Biosensors based on organic field-effect transistors (OFETs) have become one of the most advanced biosensor platforms because of their inherent ability to amplify received signals. Furthermore, OFET-based biosensors have been widely used in the detection of DNA, protein, cell, glucose and other biological substances due to its high sensitivity, fast analysis speed, label-free detection, small size and simple operation. This mini review briefly discusses the organic small molecule semiconductor materials, device configurations, basic principles and application fields of OFETs-based biosensors.

Micelles as nanocarriers not only offer new opportunities for early diagnosis and treatment of malignant cancers but also encounter numerous barriers in the path of efficient delivery of drugs to diseased areas in the body. To address these issues, we developed a pH/GSH responsive nano-prodrug micelle (NLG919/PGA-Cys-PPA@Gd) with a high drug-loading ratio and controlled drug release performance for MRI-guided tumor photodynamic therapy (PDT) and immune synergistic therapy. Under normal conditions, theranostic nanomicelles remained stable and in a photo-quenched state. Upon accumulation in the tumor site, however, the micelles demonstrated tumor microenvironment (TME) triggered photoactive formed-PPA (a photosensitizer) and NLG919 (an indoleamine 2,3-dioxygenase (IDO) inhibitor) release because the amide bonds of PGA-Cys-PPA and the disulfide linkage of Cys were sensitive to pH and GSH, respectively. More importantly, these micelles could avoid the undesired PPA leakage in blood circulation due to the conjugation between PPA and polymers. Furthermore, the obtained micelles could also enhance the contrast of

Wearable sensor industry is on the rise, because it can achieve real-time monitoring, intervention and prediction functions in the field of personal health management. To date, although remarkable progress has been made and laboratory-based theoretical researches have also been confirmed, there are still only a handful of sensors that have been commercialized or clinically available due to the immaturity of technologies. Here, we make an up-to-date Review of wearable and biodegradable sensors. First, we introduce the basic concepts and transduction mechanisms of four physical sensors based on piezoresistive, capacitive, piezoelectric and triboelectric effects. Then, we survey the latest research advances in terms of wearable and biodegradable sensors, focusing our attention on material option, structure design and application exploration. In particular, the implantable sensors made from biocompatible and biodegradable materials are emphasized, which may become the mainstream research direction of green electronic products. Finally, we debate the current challenges and future trends of wearable and biodegradable sensors.

The performance of water purification by adsorption method has been limited owing to the fact that most of current available adsorbents fail to achieve satisfactory removal performance for organic micropollutants. Herein, we report the design and synthesis of novel porous polymeric adsorbent built from β-cyclodextrin (β-CD), in which β-CD molecules are arranged in an ordered bis (β-CD) tubular assemblies. The induction of bis (β-CD) units renders them high adsorption affinity toward bisphenols (bisphenol A and its analogues bisphenol B, bisphenol F and bisphenol S), the typical endocrine disruptors, via the formation of stable host-guest inclusion complexes in aquatic systems. In combination with their high porosity (Brunauer-Emmett-Teller (BET) surface area of 150 m2·g−1), abundant β-CD content and fast sorption kinetics, the obtained adsorbent outperforms commercial water purifier in elimination of bisphenol micropollutants from potable water. Our work may open a new avenue for designing highly efficient adsorbents for removal of organic micropollutants from aquatic systems.

Room temperature phosphorescence (RTP) materials have been widely noticed due to their superior optical properties in the past decade. Herein, we report the Si-assisted N, P co-doped RTP carbonized polymer dots (CPDs), prepared by one-step microwave assisted heating of 3-(2-Aminoethylamino)propyldimethoxymethylsilane and phosphoric acid aqueous solution. The obtained CPDs exhibit bright RTP with an absolute photoluminescence quantum yield 34.17%, absolute phosphorescence quantum yield 11.42% and long lifetime of 1.42 s, which lasts for about 16 s to the naked eyes. We apply the obtained CPDs into information encryption and Polyethyleneterephthalate (PET) film graphic anti-counterfeiting with facile way. Additionally, we make more efforts to realize aqueous RTP CPDs composite. The obtained aqueous CPDs composite exhibits bright aqueous RTP with absolute photoluminescence quantum yield (QY) of 12.61%, absolute phosphorescence quantum yield (QY) of 5.08% and RTP lifetime of 1.46 s, which lasts for about 10 s to the naked eyes. The RTP CPDs composite is nontoxic and biocompatible. These brilliant characteristics allow CPDs composite to be applicable in biological imaging. Thisstudy affords a new RTP material which can be easily prepared and used for information encryption, graphic anti-counterfeiting and biological imaging.

Perusing redox nanozymes capable of disrupting cellular homeostasis offers new opportunities to develop cancer-specific therapy, but remains challenging, because most artificial enzymes lack enzyme-like scale and configuration. Herein, for the first time, we leverage a defect engineering strategy to develop a simple yet efficient redox nanozyme by constructing enzyme-mimicking active centers and investigated its formation and catalysis mechanism thoroughly. Specifically, the partial Fe doping in MoOx (donated as Fe-MoOv) was demonstrated to activate structure reconstruction with abundant defect site generation, including Fe substitution and oxygen vacancy (OV) defects, which significantly enable the binding capacity and catalytic activity of Fe-MoOv nanozymes in a synergetic fashion. More intriguingly, plenty of delocalized electrons appear due to Fe-facilitated band structure reconstruction, directly contributing to the remarkable surface plasmon resonance effect in the near-infrared (NIR) region. Under NIR-II laser irradiation, the designed Fe-MoOv nanozymes are able to induce substantial disruption of redox and metabolism homeostasis in the tumor region via enzyme-mimicking cascade reactions, thus significantly augmenting therapeutic effects. This study that takes advantage of defect engineering offers new insights into developing high-efficiency redox nanozymes.

Tumor hypoxia severely limits the therapeutic effects of photodynamic therapy (PDT). Although many methods for oxygen generation exist, substantial safety concerns, spatiotenporal uncontrollability, limited efficacy and complicated procedures have compromised their practical application. Here, we demonstrate the feasibility of a biocompatiable all-in-one organic semiconductor to provide a photoxidation catalysis mechanism of action to combat these challenges. A one-step and facile method is developed to produce gram-level C5N2 nanoparticles (NPs)-based organic semiconductor. Under 650 nm laser irradiation, the semiconductor split water to generate O2 and simultaneously produced singlet oxygen (1O2), revealing that the photocatalyst for O2 evolution and the photosensitizer (PS) for 1O2 generation could be synchronously achieved in one organic semiconductor. Furthermore, the inherent nucleus targeting capacity endows it with direct and efficient DNA photocleavage. These findings pave the way for developing organic semiconductor-based cancer therapeutic agents.

Intracellular targeting has the same potential as tissue targeting to increase therapy efficacy, especially for drugs that are toxic to DNA. By adjusting intracellular traffic, we developed a novel direct-nucleus-delivery platform based on C5 N2 nanoparticles (NPs). Supramolecular interactions of C5 N2 NPs with the cell membrane enhanced cell uptake; abundant edge amino groups promoted fast and effective rupture of early endosomes; and the appropriate size of the NPs was also crucial for size-dependent nuclear entry. As a proof of concept, the platform was not only suitable for the effective delivery of molecular drugs/dyes (doxorubicin, hydroxycamptothecine, and propidium iodide) and MnO2 nanoparticles to the nucleus, but was also photoresponsive for nucleus-targeting photothermal therapy (PTT) and photodynamic therapy (PDT) to further greatly increase anticancer efficacy. This strategy might open the door to a new generation of nuclear-targeted enhanced anticancer therapy.

Appropriate disposal of radioactive iodine in spent nuclear fuel reprocessing represents an acknowledged challenging topic. Currently, most solid sorbents for radioactive iodine treatment are suffering from the risk of fire and explosion due to the presence of nitrogen oxides in the exhaust stream. Herein, we reported for the first time the use of porous hexagonal boron nitride (porous BN) to capture radioactive iodine and further studied its practicability and iodine-removal performance. A series of tests, such as flammability, acid leaching durability and so on, revealed the excellent thermal stability, acid-resistance, anti-oxidation activity and hydrophobic properties of porous BN. It should be highlighted that porous BN exhibits outstanding flame-retardant ability, which is superior to that of well-studied MOF and POP iodine-removal materials. These merits will enormously reduce the risk of fire and explosion in the exhaust stream and endow this material with great potential in practical radioactive waste reprocessing. Benefiting from the porous properties and Lewis acid–base interaction, porous BN demonstrated 213 wt% adsorption capacity for iodine vapor, which is a considerably high value among inorganic materials. The iodine removal performance of porous BN was further demonstrated by a column test under simulated reprocessing. Combining its superb physicochemical properties with iodine removal capacity, porous BN is thereby a promising iodine sorbent for safe and effective radioactive iodine capture in practical applications.

Effectively capturing volatile radioiodine produced during the spent nuclear fuel reprocessing is an efficient way of the safe utilization of nuclear power. However, all the existing capture methods fail to immobilize radioiodine reliably due to the weak binding interaction between radioiodine and adsorbent, resulting in unstable binding sites and further iodine liberation. Herein, we report a pioneering approach to overcome this challenge by synthesizing a melamine-based polymer (MFP) with high binding energy to I3− species instead of the conventional I2 molecules. Both experimental and theoretical results confirmed that the iodine atoms of I3− strongly interact with MFP via synergistic hydrogen bonds. According to this, the highest binding energy to radioiodine was achieved (Gibbs free energy: −260.38 kcal mol−1, which was about four times stronger than that of the widely used Ag–I ion bond), enabling effective enrichment of volatile iodine without any iodine escape. The extraordinary energy not only allowed the MFP to capture iodine steadily and durably, but also afforded ultrahigh adsorption capacity (637 wt%, in iodine vapor). More interestingly, we found that the MFP showed promising results for removing NO2, which coexisted with iodine in the off-gas stream. To the best of our knowledge, this is the first attempt to remove both radioiodine and NO2. Last but not least, the MFP also exhibited satisfactory practical applications under simulated spent nuclear fuel reprocessing conditions.

Nanotheranostic agents that can simultaneously provide real-time tracking and accurate treatment at tumor sites are playing an increasingly important role in medicine. Herein, a novel polypyrrole (PPy)-based theranostic agent containing double rare-earth elements (PPy@BSA-Gd/Dy NPs) was successfully synthesized via an integrated strategy combining biomineralization and oxidation polymerization. The obtained PPy@BSA-Gd/Dy NPs with a diameter of approximately 59.48 ± 6.12 nm exhibited excellent solubility, long-term stability, superior biocompatibility, and negligible toxicity. Importantly, due to its intrinsic paramagnetic and strong X-ray attenuation ability, this agent demonstrated brilliant imaging performance in both T1/T2-weighted magnetic resonance imaging (MRI) and X-ray computed tomography (CT) imaging in vitro and vivo. Additionally, with an excellent photothermal conversion efficiency (26.61%) upon irradiation by an 808 nm laser, this theranostic agent showed significant photothermal cytotoxicity against HeLa cells and 4T1 cells in vitro and antitumor efficacy through intravenous injection in vivo. Meanwhile, biodistribution and blood circulation were also used to explore its fate in vivo. In summary, this study highlighted the versatility and practicability of PPy@BSA-Gd/Dy NPs and also suggested that the agent may be a promising candidate for T1/T2-weighted MRI/CT tri-modal imaging guided photothermal cancer therapy.

Severe side effects and poor therapeutic efficacy are the main drawbacks of current anticancer drugs. These problems can be mitigated by targeting, but the targeting efficacy of current drugs is poor and urgently needs improvement. Taking this into consideration, this Review first summarizes the current targeting strategies for cancer therapy in terms of cancer tissue and organelles. Then, we analyse the systematic targeting of anticancer drugs and conclude that a typical journey for a targeted drug administered by intravenous injection is a CTIO cascade of at least four steps. Furthermore, to ensure high overall targeting efficacy, the properties of a targeting drug needed in each step are further analysed, and some guidelines for structure optimization to obtain effective targeting drugs are offered. Finally, some viewpoints highlighting the crucial problems and potential challenges of future research on targeted cancer therapy are presented. This review could actively promote the development of precision medicine against cancer.

X-ray computed tomography (CT) is one of the most widely used imaging modalities in the clinic. Current commercialized CT contrast agents are mainly small iodinated molecules. These contrast agents suffer from drawbacks such as short circulation times in vivo . Recent advance highlight the importance of nano-sized CT imaging probes that exhibit good biocompatibility and long circulation time. Most importantly, their surface features enable the design of multifunctional imaging probes. This review provides a comprehensive introduction to recent development of nano-sized CT imaging probes and some future directions are presented.

The anticancer drug doxorubicin (DOX) is locked in the mesoporous silica nanoparticle by coating FeIII-TA polymer, and its burst release can be achieved under acidic environment, along with the decreased longitudinal relaxivity. This nanoplatform shows great potential to monitoring the drug delivery process and the fate of the nanocarrier.

The direct monitoring of trace water in real time during electrochemical cycles is of vital importance because water impurities are one of the causes of reduced lifetimes and capacity fading in Li-ion batteries. However, the most common Karl-Fischer titration lacks the ability to perform real-time monitoring of trace water while the battery is operating. Here, we demonstrate the use of nanosized coordination polymers as a sensing platform for the rapid and highly sensitive detection of water molecules, which gives a distinguishable turn-on fluorescence (FL) response toward water with a quantifiable detection range from 0 to 1.2% v/v, offering a novel opportunity to monitor trace water during electrochemical cycles. To demonstrate the practical value of our platform, we designed an in situ measurement system using nanosized coordination polymers as an electrolyte additive. Within the platform, the findings indicate that trace water is indeed generated during the first discharge process, in which the FL intensity shows a linear increase over time along with the gradual formation of water. We believe that this strategy provides new insights into the in situ monitoring of complex electrochemical processes, and it may help to pave the way for the development of new operando analytical techniques for lithium-ion batteries.

Carbon nanotubes-supported non-precious metal nanoparticles emerge as promising catalyst candidate for fuel cell. Although it is well known that carbon nanotubes can influence the catalytic activity of transition metal nanoparticles, insights into whether the unrolling of carbon nanotubes can be exploited to enhance the oxygen reduction performance are lacking. Herein we demonstrate the transformation from FeS/Fe3C nanoparticles coupled S, N dual doped carbon nanotubes (FeS/Fe3C@S, N-C) to nanosheets can yield the improved oxygen reduction performance. Under a glucose protective strategy, the walls of FeS/Fe3C@S, N-C nanotubes were unrolled and extended, creating FeS/Fe3C nanoparticles coupled S, N dual doped carbon nanosheets (FeS/Fe3C@S, N-C g(50)) with larger surface area and higher doping level, which allowed for the exposure of sufficient accessible active sites. Consequently, FeS/Fe3C@S,N-C g(50) exhibited an onset potential of 0.938 V, together with low peroxide yield, good selectivity and durability. Our investigations showed that the carbon matrix with an opened structure and abundant accessible active sites is critical to the electrocatalysts. Furthermore, the synergetic effect of the S, N dual doped carbon nanosheets and FeS/Fe3C nanoparticles contributed to the enhanced oxygen reduction activity. We expect the presented structure–activity relationship can provide guidance for future design of advanced electrocatalysts.

Early detection of ovarian cancer, the most lethal type of gynecologic cancer, can dramatically improve the efficacy of available treatment strategies. However, few screening tools exist for rapidly and effectively diagnosing ovarian cancer in early stages. Here, we present a facile "lock-key" strategy, based on rapid, specific detection of plasma lysophosphatidic acid (LPA, an early stage biomarker) with polydiacetylenes (PDAs)-based probe, for the early diagnosis of ovarian cancer. This strategy relies on specifically inserting LPA "key" into the PDAs "lock" through the synergistic electrostatic and hydrophobic interactions between them, leading to conformation transition of the PDA backbone with a concomitant blue-to-red color change. The detailed mechanism underlying the high selectivity of PDAs toward LPA is revealed by comprehensive theoretical calculation and experiments. Moreover, the level of LPA can be quantified in plasma samples from both mouse xenograft tumor models and patients with ovarian cancer. Impressively, this approach can be introduced into a portable point-of-care device to successfully distinguish the blood samples of patients with ovarian cancer from those of healthy people, with 100% accuracy. This work provides a valuable portable tool for early diagnosis of ovarian cancer and thus holds a great promise to dramatically improve the overall survival.

Titanium nitride, an alternative plasmonic material to gold with unique physiochemical properties, has been widely used in microelectronics, biomedical devices and food-contact applications. However, its potential application in the area of biomedicine has not been effectively explored. With the spectral match of their plasmon resonance band and the biological transparency window as well as good biocompatibility, titanium nitride nanoparticles (TiN NPs) are promising photoabsorbing agents for photothermal therapy (PTT) and photoacoustic imaging. Nevertheless, the photothermal performance of TiN NPs has not been investigated until now. Here, we presented the investigation of employing TiN NPs as photoabsorbing agents for in vivo photoacoustic tomography (PAT) imaging-guided photothermal cancer therapy. Our experimental results showed that TiN NPs could strongly absorb the NIR light and provided up to 48% photothermal conversion efficiency. After PEGylation, the resultant nanoparticles demonstrated improved physiological stability and extensive blood retention. Following intravenously administration, they could simultaneously enhance the photoacoustic signals of the tumor region and destroy tumors in the tumor-bearing mouse model by taking advantage of the photothermal effect of the TiN NPs. Our findings highlighted the great potential of plasmonic TiN NPs in detection and treatment of cancer.

Accelerating the rate-limiting oxygen reduction reaction (ORR) at the cathode remains the foremost issue for the commercialization of fuel cells. Transition metal–nitrogen–carbon (M–N/C, M = Fe, Co, etc.) nanostructures are the most promising class of non-precious metal catalysts (NPMCs) with satisfactory activities and stabilities in practical fuel cell applications. However, the long-debated nature of the active sites and the elusive structure-performance correlation impede further developments of M–N/C materials. In this review, we present recent endeavors to elucidate the actual structures of active sites by adopting a variety of physicochemical techniques that may provide a profound mechanistic understanding of M–N/C catalysts. Then, we focus on the spectacular progress in structural optimization strategies for M–N/C materials with tailored precursor architectures and modified synthetic routes for controlling the structural uniformity and maximizing the number of active sites in catalytic materials. The recognition of the right active centers and site-specific engineering of the nanostructures provides future directions for designing advantageous M–N/C catalysts.

Nanotechnology-mediated antioxidative therapy is emerging as a novel strategy for treating a myriad of important diseases through scavenging excessive reactive oxygen and nitrogen species (RONS), a mechanism critical in disease development and progression. However, similar to antioxidative enzymes, currently studied nano-antioxidants have demonstrated scavenging activity to specific RONS, and sufficient antioxidative effects against multiple RONS generated in diseases remain elusive. Here we propose to develop bioinspired melanin nanoparticles (MeNPs) for more potent and safer antioxidative therapy. While melanin is known to function as a potential radical scavenger, its antioxidative mechanisms are far from clear and its applications for the treatment of RONS-associated diseases have yet to be well explored. In this study, we provide for the first time exhaustive characterization of the activities of MeNPs against multiple RONS including O2•−, H2O2, •OH, •NO, and ONOO−, the main toxic RONS generated in diseases. The potential of MeNPs for antioxidative therapy has also been evaluated in vitro and in a rat model of ischemic stroke. In addition to the broad defense against these RONS, MeNPs can also attenuate the RONS-triggered inflammatory responses through suppressing the expression of inflammatory mediators and cytokines. In vivo results further demonstrate that these unique multi-antioxidative, anti-inflammatory and biocompatible features of MeNPs contribute to their effective protection of ischemic brains with negligible side effects.

Inorganic layered ion-exchangers have received extensive attention in the field of environmental remediation due to their high chemical, thermal and radiolytic stability, large surface areas, and excellent ion exchange capacities. These materials have been widely investigated as adsorbents for decontamination of toxic metal pollutants, such as heavy metals and nuclear waste related metal ions in aquatic systems. In this review, we describe the most important inorganic layered ion-exchangers including layered double hydroxides, layered metal oxides, and layered metal sulfides in terms of their structural features and ion exchange properties as well as potential applications in remediation of metal polluted aquatic systems. Furthermore, the future challenges and outlooks for these materials are also discussed.

Biodegradable polymeric nanomaterials can be directly broken down by intracellular processes, offering a desirable way to solve toxicity issues for cancer diagnosis and treatment. Among them, aliphatic polycarbonates are approved for application in biological fields by the United States Food and Drug Administration (FDA), however, high hydrophobicity, deficient functionality and improper degradation offer significant room for improvement in these materials. Methods: To achieve progress in this direction, herein, we demonstrate that CO2-based amphiphilic polycarbonates (APC) with improved hydrophilicity and processability can be used as a reliable and efficient platform for tumor imaging. To better investigate their potential, we devised a convenient strategy through conjugation of APC with gadolinium (Gd). Results: The resulting polymeric micelles (APC-DTPA/Gd) exhibit excellent magnetic resonance imaging performance, simultaneously enabling real-time visualization of bioaccumulation and decomposition of polymeric micelles in vivo. Importantly, these micelles can be degraded to renally cleared products within a reasonable timescale without evidence of toxicity. Conclusion: Our findings may help the development of CO2-based amphiphilic polycarbonate for cancer diagnosis and treatment, accompanied by their low-toxicity degradation pathway.

Intracellular targeting has the same potential as tissue targeting to increase therapy efficacy, especially for drugs that are toxic to DNA. By adjusting intracellular traffic, we developed a novel direct-nucleus-delivery platform based on C

Nanoagents achieving photodynamic therapy (PDT) and photothermal therapy (PTT) combination treatment with improved therapeutic effect are highly desirable. However, the incorporation of both PDT and PTT into a single nanoagent often requires multistep fabrication process. Herein, we report that photoactive porphyrin ligands have been successfully introduced into Zn-TCPP structure to construct the nanoagents that possesses photodynamic performance and photothermal performance simultaneously. Such a nanoagent enables the generation of single oxygen and heat under laser irradiation. Additionally, it exhibits satisfactory biocompatibility and high light toxicity against cancer cells. The current work provides a feasible approach to introduce both PDT and PTT into a single nanoplatform.

Nuclear power plants are expanding rapidly around the world to meet the growing energy demands. The effective capture of volatile radioiodine is an important area of research that is associated with the reprocessing of used nuclear fuel. However, the construction of high-performance adsorbents depends largely on an in-depth comprehension of the underlying binding mechanism at the gas-solid interface. Recently, a growing number of studies have demonstrated the pivotal role of optimizing the interface properties and binding sites, thereby regulating the interaction between the host (adsorbent) and guest (iodine) molecules. In this review, we first introduce the present understanding of the main mechanism for removing volatile radioiodine, and give more detailed descriptions of the capture pathways of specified adsorbents. Then, we discuss nanointerface engineering in materials, which have been conducted in various studies, and review the result of recent studies. Finally, nanointerface engineering based on the adjustment of host-guest interactions are summarized, and future research directions are presented.

Molybdenum disulphide (MoS2) has been an attractive target for investigations in the fields of catalysis, sensing, energy storage, electronics, and optoelectronics. However, its potential application in the important area of environmental cleanup has not yet been effectively explored. With an intrinsically sulfur-rich characteristic and unique 2D structure, MoS2 should be capable of mercury capture and removal. However, successful attempts to apply MoS2 to mercury removal are quite rare, presumably because the vast majority of sulfur atoms are located inside the bulk of MoS2 and are therefore inaccessible for mercury ions. Here, the first experimental evidence that MoS2 nanosheets with widened interlayer spacing are capable of mercury capture, with an extremely high mercury uptake capacity closely matching the theoretically predicted value (2506 mg g−1) and the largest distribution coefficient value (3.53 × 108 mL g−1) is provided. Remarkably, a single treatment of industrial wastewater (polyvinyl chloride industry) with this modified MoS2 could efficiently reduce the mercury concentration (126 p.p.b.) below U.S. Environmental Protection Agency limits for drinking water standards. The findings open up the possibility of expanding the applications of transition metal dichalcogenides in environmental remediation.

Achieving high-resolution imaging of bone-cracks and even monitoring them in live organisms are of great significance for understanding their extreme biological effects but remain quite challenging, especially for adopting commercial imaging systems. Herein, we explore the use of the clinical gemstone spectral computed tomography (GSCT) technique as a powerful tool for targeted imaging of bone-cracks in rats via intramuscularly administrating crack-targeted ytterbium-based contrast agents (CAs). Material density images of GSCT reveal that bone-cracks targeted with CAs can be successfully differentiated from healthy bone based on their different X-ray attenuation characteristics, giving GSCT a distinct advantage over conventional CT. More importantly, the superior imaging capability of GSCT allows us to real-time monitor the targeting and accumulation of CAs toward bone-crack in vivo. These results highlight that clinical GSCT, combined with ytterbium-based CAs, provides a promising opportunity for understanding bone-related diseases in the future.

In this work, a novel multiplex electrochemiluminescence (ECL) DNA sensor has been developed for determination of hepatitis B virus (HBV) and hepatitis C virus (HCV) based on multicolor CdTe quantum dots (CdTe QDs) and Au nanoparticles (Au NPs). The electrochemically synthesized graphene nanosheets (GNs) were selected as conducting bridge to anchor CdTe QDs551-capture DNA(HBV) and CdTe QDs607-capture DNA(HCV) on the glassy carbon electrode (GCE). Then, different concentrations of target DNA(HBV) and target DNA(HCV) were introduced to hybrid with complementary CdTe QDs-capture DNA. Au NPs-probe DNA(HBV) and Au NPs-probe DNA(HCV) were modified to the above composite film via hybrid with the unreacted complementary CdTe QDs-capture DNA. Au NPs could quench the electrochemiluminescence (ECL) intensity of CdTe QDs due to the inner filter effect. Therefore, the determination of target DNA(HBV) and target DNA(HCV) could be achieved by monitoring the ECL DNA sensor based on Au NPs-probe DNA/target DNA/CdTe QDs-capture DNA/GNs/GCE composite film. Under the optimum conditions, the ECL intensity of CdTe QDs551 and CdTe QDs607 and the concentration of target DNA(HBV) and target DNA(HCV) have good linear relationship in the range of 0.0005-0.5 nmol L(-1) and 0.001-1.0 nmol L(-1) respectively, and the limit of detection were 0.082 pmol L(-1) and 0.34 pmol L(-1) respectively (S/N = 3). The DNA sensor showed good sensitivity, selectivity, reproducibility and acceptable stability. The proposed DNA sensor has been employed for the determination of target DNA(HBV) and target DNA(HCV) in human serum samples with satisfactory results.

Despite the progress in the design and synthesis of theranostic agents, limitations on efficiency and safety offer significant room for improvement in these agents. Inspired by the natural binding ability of polydopamine nanospheres (PDAs) with iron ion, a simple and versatile synthesis strategy is developed to prepare biodegradable coordination polymer (CP) encapsulated PDAs nanocomplex (PDAs@CPx, x = 3, 6, 9). We found that the PDAs@CP3 can serve as a T1/T2 dual mode contrast agent (DMCA) for magnetic resonance imaging (MRI), which possesses high longitudinal (r1 = 7.524 mM(-1) s(-1)) and transverse (r2 = 45.92 mM(-1) s(-1)) relaxivities. In this system, benefitting from the high photothermal conversion efficiency derived from PDAs, DOX loaded PDAs@CP3 nanocomplex is able to not only destroy the tumor directly by heat, but also stimulate the chemotherapy by enabling NIR-responsive on demand delivery of DOX. To the best of our knowledge, this is the first example exploring the potential of PDAs@CPx nanocomplex for T1/T2 dual mode MRI-guided chemo-photothermal synergistic therapy. This work extends the currently available theranostic agents, and opens up new avenues to rationally design the high-performance T1/T2 DMCA.

In this paper, we designed a novel near-infrared aptamer-mediated fluorescence “turn off–on” nanosensor for highly sensitive and selective detection of kanamycin based on CuInS2 quantum dots (QDs)@graphene oxide (GO) nanocomposites. The carboxy groups on the surface of CuInS2 QDs (modified with mercaptopropionic acid) were conjugated with amino terminal kanamycin-binding Ky2 aptamer to form the Ky2-CuInS2 QDs in the presence of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide. Then, the Ky2-CuInS2 QDs were facilely immobilized on the surface of GO through π–π stacking interaction between the nucleobases and GO, which caused the fluorescence of Ky2-CuInS2 QDs “turned off”. In the presence of kanamycin, the Ky2-CuInS2 QDs desorb from the surface of GO and bind to kanamycin with high affinity and specificity. As a result, the quenched fluorescence “turned on”. Under the optimum conditions, there was a good linear relationship between I/I0 (I and I0 were the fluorescence intensity of Ky2-CuInS2 QDs@GO in the presence and absence of kanamycin, respectively) and kanamycin concentration in the range of 0.3–45 nmol L−1 (0.174–26.1 μg L−1), with the detection limit of 0.12 nmol L−1 (0.070 μg L−1). The present nanosensor was utilized to detect kanamycin in the human serum, urine and milk samples with satisfactory results.

Developing non-precious metal electrocatalysts (NPMCs) for the oxygen reduction reaction (ORR) is of paramount importance for commercial implementation of several clean energy techniques (e.g. proton exchange membrane fuel cells). However, limited understanding of the ORR catalytic mechanism of NPMCs greatly hinders the progress in the precise fabrication of NPMCs at the molecular or atomic level. Recently, an increasing number of studies have demonstrated the crucial role of a carbon matrix in exposing, stabilizing, and activating the catalytic sites, thus providing a platform to identify the nature of NPMCs. Herein, the unique structural effects of a carbon matrix in NPMCs are first reviewed to inspire the development of more advanced NPMCs for the ORR.

Enhancing the catalytic activity of non-precious metal catalysts (NPMCs) for oxygen reduction reaction (ORR) requires determination of active centers and a better understanding of the structure–activity relationship. However, key technical challenges in controlling the structural uniformity of NPMCs and maximizing the number of exposed active sites make this goal hard to achieve. Here, inspired by the facile self-assembly strategy for DNA metallization, we have fabricated Co–adenine nanocomposite spheres (Co–A NSs) with uniform structures and well-recognized Co–N4 configuration. Direct pyrolysis of Co–A NSs leads to the formation of monodisperse rambutan-like Co–N/C composites with high porosity and degree of graphitization, as well as homogeneous and high-density Co–N active sites, which endow them with excellent ORR catalytic activity in both base and acid conditions. With Co–N/C as the cathode catalyst, the assembled alkaline direct methanol fuel cell (ADMFC) generates extremely high open-circuit voltage (0.80 V) and unprecedentedly high maximum output power density (40.1 mW cm−2), which is successfully utilized to illuminate a light-emitting diode (LED) lantern. Moreover, the easily controlled structure of Co–N/C catalysts enables us to further reveal their structure–activity relationship, which may provide guidance for future design of advanced electrocatalysts.

The serious health risk of sunscreens is mainly attributed to the self-induced damages. Not merely spontaneously generate deleterious reactive oxygen species (ROS), sunscreens also can penetrate through the skin and enter the body, resulting in a series of detrimental effects. Although numerous attempts have been made to remove these risks, safety hazards from sunscreens have not been fully overcome yet. Mainly because almost all of the currently proposed strategies are limited to address only one issue-either the restriction of self-generated ROS or improvement of retention. Here, we integrate the two issues as a whole, enabling us to develop a novel dual-protective sunscreen nanoparticles (DSNPs) to combat the above inherent defects of sunscreens at the same time. The antioxidants-wrapped sunscreen cores are encapsulated into aldehyde-functionalized outer silica shell, which can not only drastically scavenge self-generated ROS, but also achieve strong attachment with the skin surface. We validate the ultra-high efficiency of this dual-protective strategy through a series of in vitro and in vivo experimentations. Specifically, the DSNPs achieve the most efficient scavenging efficiencies of self-generated ROS and are efficiently prevented from entering the body. This dual-protective sunscreen opens a new dimension for the rational design of next-generation sunscreen with minimal side effects.

The failure of complete tumor resection during cancer surgery is a leading cause of lethal recurrence and metastasis. However, achieving accurate delineation of tumor margins intraoperatively remains extremely difficult because the infiltrated nature of a tumor usually gives an obscure margin and spreading microtumors. Recent studies show that surface-enhanced Raman scattering (SERS) has the potential to depict precisely the actual tumor extent with high sensitivity, specificity, and spatial resolution; thus providing a promising platform to improve the therapeutic efficiency. In this review, we discuss the recent progress in the use of SERS spectroscopy for intraoperative image-guided resection. We highlight key successes in the development of SERS tags and give insights into the design mechanism of rational SERS tags. We also discuss how to improve the performance of intraoperative navigation based on SERS and explore the challenges and future opportunities for the development of a more effective SERS-based platform. Graphical abstract ᅟ.

The lack of point-and-shoot detection methods of alcoholic beverages (ABs) available for ordinary people is a common cause of the overflow of various counterfeit ABs. Here, we, for the first time, provide a point-and-shoot identification for ABs via a smartphone. Using density functional theory, we find the binding ability of an ethylenediamine-functionalized polydiacetylene (P4) can reach a desirable trade-off among organic molecules in ABs. We therefore construct a versatile array consisting of P4 with different concentrations, which is able to generate unique color response patterns toward different ABs. The color response patterns are further analyzed by a custom-designed image processing algorithm based on machine learning. Finally, the identification of ABs can be achieved by capturing and analyzing the color pattern using an imaging recognition programmer on a smartphone, and the entire process is as fast as quick response (QR) code scanning. Our point-and-shoot strategy makes the identification of ABs accessible to every mobile phone user.

X-ray computed tomography (CT) has been widely used as a powerful diagnostic tool in clinics because it can provide high-resolution 3D tomography of the anatomic structure based on the distinctive X-ray absorptions between different tissues. Currently, CT contrast agents are mainly small iodinated molecules, which suffer from drawbacks such as short bloodretention time, nonspecific in vivo biodistribution, and renal toxicity. Utilization of nanoparticles as potential CT contrast agents to overcome the aforementioned issues has advanced rapidly. In this mini review, we introduce current research efforts in the development of nanoparticulate CT contrast agents and discuss the challenges for additional breakthroughs in this field.

Lanthanide-based multimodal probes with high sensitivity, simple synthesis strategy, and good biocompatibility promise new applications for clinical diagnosis. However, today's challenge is not only to develop high-performance multimodal probes for more accurate and reliable diagnosis, but also to understand the fate of these probes in vivo. In this context, a novel PEGylated Dy-doped NaGdF4 nanoprobe (PEG-NaGdF4:Dy) was designed and fabricated as a T1/T2-weighted MRI/CT imaging agent. This nanoprobe has a distinct longitudinal relaxivity (r1 = 5.17 mM(-1) s(-1)), relatively high transverse relaxivity (r2 = 10.64 mM(-1) s(-1)), and exhibits strong X-ray attenuation properties (44.70 HU L g(-1)) in vitro. Furthermore, T1/T2-weighted MRI/CT imaging in vivo confirmed that this PEG-NaGdF4:Dy nanoprobe could lead to a significant contrast enhancement effect on liver, spleen and kidney at 24 h post injection. The MTT assay, histological analysis, and biodistribution investigation demonstrated that this multifunctional nanoprobe possessed relatively low cytotoxicity, negligible tissue damage and could be completely excreted out of the body of mice as time prolonged. Therefore, the present PEG-NaGdF4:Dy nanoprobe has the potential for the development of multifunctional T1/T2-weighted MRI/CT imaging to provide more comprehensive and accurate diagnosis information.

Operando fluorescence spectroscopy provides an effective platform for the direct monitoring of trace water in an operating Li-ion battery, with the assistance of nanosized coordination polymers as fluorescent probes., The direct monitoring of trace water in real time during electrochemical cycles is of vital importance because water impurities are one of the causes of reduced lifetimes and capacity fading in Li-ion batteries. However, the most common Karl-Fischer titration lacks the ability to perform real-time monitoring of trace water while the battery is operating. Here, we demonstrate the use of nanosized coordination polymers as a sensing platform for the rapid and highly sensitive detection of water molecules, which gives a distinguishable turn-on fluorescence (FL) response toward water with a quantifiable detection range from 0 to 1.2% v/v, offering a novel opportunity to monitor trace water during electrochemical cycles. To demonstrate the practical value of our platform, we designed an in situ measurement system using nanosized coordination polymers as an electrolyte additive. Within the platform, the findings indicate that trace water is indeed generated during the first discharge process, in which the FL intensity shows a linear increase over time along with the gradual formation of water. We believe that this strategy provides new insights into the in situ monitoring of complex electrochemical processes, and it may help to pave the way for the development of new operando analytical techniques for lithium-ion batteries.

Nitrogen-doped species (NDs) are theoretically accepted as a determinant of the catalytic activity of metal-free N-doped carbon (NC) catalysts for oxygen reduction reaction (ORR). However, direct relationships between ND type and ORR activity have been difficult to extract because the complexity of carbon matrix impairs efforts to expose specific NDs. Herein, we demonstrate the fabrication of a 3D hierarchically porous NC catalyst with micro-, meso-, and macroporosity in one structure, in which sufficient exposure and availability of inner-pore catalytic sites can be achieved due to its super-high surface area (2191 cm(2) g(-1) ) and interconnected pore system. More importantly, in-situ formation of graphitic-N species (GNs) on the surface of NC stimulated by KOH activation enables us to experimentally reveal the catalytic nature of GNs for ORR, which is of great significance for the design and development of advanced metal-free NC electrocatalysts.