Novel Ag3PO4/ZnWO4-modified graphite felt electrode for photoelectrocatalytic removal of harmful algae: Performance and mechanism.

A novel Ag3PO4/ZnWO4-modified graphite felt electrode (AZW@GF) was prepared by drop coating method and applied to photoelectrocatalytic removal of harmful algae. Results showed that approximately 99.21% of chlorophyll a and 91.57% of Microcystin-LR (MCLR) were degraded by the AZW@GF-Pt photoelectrocatalytic system under the optimal operating conditions with a rate constant of 0.02617 min-1 and 0.01416 min-1, respectively. The calculated synergistic coefficient of photoelectrocatalytic algal removal and MC-LR degradation by the AZW@GF-Pt system was both larger than 1.9. In addition, the experiments of quenching experiments and electron spin resonance (ESR) revealed that the photoelectrocatalytic reaction mainly generated •OH and •O2- for algal removal and MC-LR degradation. Furthermore, the potential pathway for photoelectrocatalytic degradation of MC-LR was proposed. Finally, the photoelectrocatalytic cycle algae removal experiments were carried out on AZW@GF electrode, which was found to maintain the algae removal efficiency at about 91% after three cycles of use, indicating that the photoelectrocatalysis of AZW@GF electrode is an effective emergency algae removal technology.

Layer-by-layer assembled graphitic carbon nitride membranes for water treatment.

Meeting societal demand for potable water supply remains one of the prioritized challenges faced in the modern era. The anthropogenic intervention has led to a dire situation threatening ecological balance and human health. There is an inevitable need for the development of new technologies and innovations in existing technologies for water treatment. Photocatalytic Membrane technology, encompassing the merits of membrane filtration and photocatalytic degradation has evolved as a potential and reliable technology for sustainable water treatment. Innovations in photocatalytic materials and membrane fabrication techniques can lead to the goal of commercialization of membrane water treatment technology. Herein, we demonstrate the potential of graphitic carbon nitride (g-C3N4) and its functionalized analog as photocatalytic membranes for sustainable water treatment. g-C3N4 and Tetracarboxyphenylporphyrin sensitized g-C3N4 (g-C3N4/TCPP) was introduced onto commercial nylon membrane surface via a layer-by-layer (LBL) assembly method using chitosan and sodium salt of polystyrene sulphonic acid as polyelectrolytes. The fabricated membranes were characterized to ensure the integration of the photocatalysts. The performance of the membranes for water treatment was assessed by selecting some common dyes as model pollutants. The modified membranes exhibited excellent flux recovery and could afford high rejection rates upon irradiation indicating the prospects for sustainable filtration.

Covalent RGD-graphene-phthalocyanine nanocomposite for fluorescence imaging-guided dual active/passive tumor-targeted combinatorial phototherapy.

Poor tumor selectivity, low stability and quenched fluorescence are the main challenges to be overcome for nanomedicine, and are mainly caused by the dissociation of the nanostructure and aggregation of chromophores in the biological environment. Herein, covalently connected nanoparticles RGD-graphene-phthalocyanine (RGD-GO-SiPc) were constructed based on RGD peptide, silicon phthalocyanine (SiPc) and graphene oxide (GO) via a conjugation reaction for fluorescence imaging-guided cancer-targeted combinatorial phototherapy. The prepared RGD-GO-SiPc exhibited supreme biological stability, high-contrast fluorescence imaging, significantly enhanced NIR absorption, high photothermal conversion efficiency (25.6%), greatly improved cancer-targeting capability, and synergistic photodynamic (PDT) and photothermal therapy (PTT) efficacy along with low toxicity. Both in vitro and in vivo biological studies showed that RGD-GO-SiPc is a kind of promising multifunctional nanomedicine for fluorescence imaging-guided combined photothermal and photodynamic therapy with dual active/passive tumor-targeting properties.

Injectable and self-healing nanocomposite hydrogel loading needle-like nano-hydroxyapatite and graphene oxide for synergistic tumour proliferation inhibition and photothermal therapy.

Non-chemotherapeutic tumour treatment has received extensive attention due to its having fewer side effects as compared to chemotherapy. However, nanomaterials-based non-chemotherapy still faces limitations such as poor targeting and low retention. Therefore, a Schiff base cross-linked hydrogel was designed and prepared using aldehyde-modified polyethylene glycol (PEG) and carboxymethyl chitosan (CMC). This hydrogel has good injectable and self-healing properties and can carry graphene oxide (GO) as a photothermal agent and needle-like nano-hydroxyapatite (HAP) as a tumour inhibitor. Combined with tumour proliferation inhibition therapy and photothermal therapy, the nanocomposite hydrogel system can avoid the side effects of chemotherapy and improve the accuracy of tumour treatment. The PEG-CMC/HAP/GO nanocomposite hydrogel system has a porous structure, good injectability and self-healing properties to meet the mechanical requirements. In vitro cell characterization showed that GO is phototoxic to tumour cells, HAP can inhibit the proliferation of tumour cells, the nanocomposite hydrogel remained in the tumour site, and the encapsulated GO and HAP did not transfer to the normal site and cause cell damage. In the in vivo investigation, the breast cancer tumour-bearing mice, the model animals for tumour treatment, were treated with an intratumoral injection of the PEG-CMC/HAP/GO nanocomposite hydrogel. This functional self-healing hydrogel loaded with GO and HAP effectively inhibited tumour cell proliferation and realized the synergistic effect of photothermal therapy, which is expected to become a new effective treatment approach for tumours.

3D-Printed Multifunctional Polyetheretherketone Bone Scaffold for Multimodal Treatment of Osteosarcoma and Osteomyelitis.

In this work, we developed the first 3D-printed polyetheretherketone (PEEK)-based bone scaffold with multi-functions targeting challenging bone diseases such as osteosarcoma and osteomyelitis. A 3D-printed PEEK/graphene nanocomposite scaffold was deposited with a drug-laden (antibiotics and/or anti-cancer drugs) hydroxyapatite coating. The graphene nanosheets within the scaffold served as effective photothermal agents that endowed the scaffold with on-demand photothermal conversion function under near-infrared laser irradiation. The bioactive hydroxyapatite coating significantly boosted the stem cell proliferation in vitro and promoted new bone growth in vivo. The presence of antibiotics and anti-cancer drugs enabled eradication of drug-resistant bacteria and ablation of osteosarcoma cancer cells, the treatment efficacy of which can be further enhanced by on-demand laser-induced heating. The promising results demonstrate the strong potential of our multi-functional scaffold in applications such as bone defect repair and multimodal treatment of osteosarcoma and osteomyelitis.

Near-Infrared Light-Triggered Unfolding Microneedle Patch for Minimally Invasive Treatment of Myocardial Ischemia.

It is hard to achieve safe, effective, and minimally invasive therapies on myocardial infarction (MI) via conventional treatments. To address this challenge, a vascular endothelial growth factor (VEGF)-loaded and near-infrared (NIR)-triggered self-unfolding graphene oxide (GO)-poly(vinyl alcohol) (PVA) microneedle (MN) patch was designed and fabricated to treat MI through a minimally invasive surgery (MIS). The folded MN patch can be easily placed into the chest cavity through a small cut (4 mm) and quickly recover to its original shape with 10 s of irradiation of NIR light (1.5 W/cm2, beam diameter = 0.5 cm), thanks to its excellent shape memory effect and fast shape recovery ability. Meanwhile, the unfolded MN patch can be readily punctured into the heart and wrap the heart tightly, thanks to its sufficient mechanical strength and adjustable morphological structure, thus ensuring a high fixation strength to withstand the high-frequency pulsation of the heart. In addition, the prepared MN patch has low cytotoxicity and controllable and sustainable release of VEGF. More importantly, the MN patch can effectively promote neovascularization, reduce myocardial fibrosis, and restore cardiac function, which indicates its promising application prospects in MIS.

Triformyl cholic acid and folic acid functionalized magnetic graphene oxide nanocomposites: Multiple-targeted dual-modal synergistic chemotherapy/photothermal therapy for liver cancer.

Photo-chemotherapy (PCT) reveals great potential in hepatocellular carcinoma (HCC) treatment, therefore the construct of smart PCT nano-agents with high photothermal conversion efficiency and accurate drug delivery is of great significant. Herein, a novel hybrid nanomaterial MGO-TCA-FA has been designed and constructed by grafting the triformyl cholic acid (TCA) and folic acid (FA) on the surface of Fe3O4 modified graphene oxide (MGO). The doxorubicin hydrochloride (DOX) as a model drug could be effectively loaded on the MGO-TCA-FA via hydrogen bonding and π-π stacking (the drug loading amount was 1040 mg/g). The formed MGO-TCA-FA@DOX has been developed to be an effective PCT nanoplatform with the advantages of multiple-targeted drug delivery, near-infrared light (NIR) and pH triggered drug release, and photothermal conversion efficiency. In vitro experiments showed that compared with other cancer cells and normal liver cells, MGO-TCA-FA@DOX could specifically target liver cancer cells and presented significant killing ability to liver cancer cells. More importantly, in vivo experiments indicated that PCT synergistic therapy (MGO-TCA-FA@DOX) revealed the best tumor inhibition (the tumor inhibition rate was about 85%) compared with chemotherapy and photothermal therapy alone. Thus, this study supplied a viable multiple-targeted PCT nano-agent for chemo-photothermal combination therapy of liver cancer.

Mussel-Inspired Immobilization of Photocatalysts with Synergistic Photocatalytic-Photothermal Performance for Water Remediation.

The serious problem of pharmaceutical and personal care product pollution places great pressure on aquatic environments and human health. Herein, a novel coating photocatalyst was synthesized by adhering Ag-AgCl/WO3/g-C3N4 (AWC) nanoparticles on a polydopamine (PDA)-modified melamine sponge (MS) through a facile layer-by-layer assembly method to degrade trimethoprim (TMP). The formed PDA coating was used for the anchoring of nanoparticles, photothermal conversion, and hydrophilic modification. TMP (99.9%; 4 mg/L) was removed in 90 min by the photocatalyst coating (AWC/PDA/MS) under visible light via a synergistic photocatalytic-photothermal performance route. The stability and reusability of the AWC/PDA/MS have been proved by cyclic experiments, in which the removal efficiency of TMP was still more than 90% after five consecutive cycles with a very little mass loss. Quantitative structure-activity relationship analysis revealed that the ecotoxicities of the generated intermediates were lower than those of TMP. Furthermore, the solution matrix effects on the photocatalytic removal efficiency were investigated, and the results revealed that the AWC/PDA/MS still maintained excellent photocatalytic degradation efficiency in several actual water and simulated water matrices. This work develops recyclable photocatalysts for the potential application in the field of water remediation.

Van der Waals enhanced interfacial interaction in cellulose/zinc oxide nanocomposite coupled by graphitic carbon nitride.

In-depth understanding of interfacial property is the key to guiding the synthesis of biomass composites with desired performance. However, the exploration is of great challenge due to limitations of experimental techniques in locating hydrogen, requiring large/good crystals and detecting a weak interaction like van der Waals (vdW). Herein, we experimentally and computationally investigated the composite cellulose/zinc oxide/g-C3N4. Hydrothermal synthesis afforded cellulose/ZnO, and then fabricated the ternary composite by adding g-C3N4 under ultrasonic condition. Three components are found to co-exist in the composite, and the ZnO nanoparticle is attaching to cellulose and coupling with g-C3N4. These experimental findings were corroborated by relativistic DFT calculations. The interfacial coupling is elaborated as contributions of dative bonds, hydrogen bonds and vdW interaction. The vdW is increased by a factor of 4.23 in the ZnO/g-C3N4 interface. This improves electron-hole separation and offers prospective application of the composite in photocatalysis, antibacteria and gas sensing.

Rational design of the Z-scheme hollow-structure Co9S8/g-C3N4 as an efficient visible-light photocatalyst for tetracycline degradation.

The development of photocatalysts with high catalytic activity that are capable of full utilization of solar energy is a challenge in the field of photocatalysis. Accordingly, in the present study, an efficient Z-scheme cage-structured Co9S8/g-C3N4 (c-CSCN) photocatalyst was constructed for the degradation of tetracycline antibiotics under visible-light irradiation. The Z-scheme charge-transfer mechanism accelerates the separation of photogenerated charge carriers and effectively improves photocatalytic activity. Moreover, c-CSCN has a hollow structure, allowing light to be reflected multiple times inside the cavity, thereby effectively improving the utilisation efficiency of solar energy. As a result, the photocatalytic activity of c-CSCN is 1.5-, 2.5-, and 5.8-times higher than those of sheet-type Co9S8/g-C3N4 (s-CSCN), c-Co9S8, and g-C3N4, respectively, for the degradation of tetracycline. c-CSCN maintains favourable photocatalytic activity over five consecutive degradation cycles, demonstrating its excellent stability. In addition, c-CSCN performs efficient tetracycline removal in different water substrates. Moreover, c-CSCN exhibits excellent ability to remove tetracycline under direct natural sunlight. This work fully demonstrates that c-CSCN has high catalytic activity and the potential for practical application as a wastewater treatment material.

Proton-Functionalized Graphitic Carbon Nitride for Efficient Metal-Free Destruction of Escherichia coli under Low-Power Light Irradiation.

Universal access to clean water has been a global ambition over the years. Photocatalytic water disinfection through advanced oxidation processes has been regarded as one of the promising methods for breaking down microbials. The forefront of this research focuses on the application of metal-free photocatalysts for disinfection to prevent secondary pollution. Graphitic carbon nitride (g-C3 N4 ) has achieved instant attention as a metal-free and visible-light-responsive photocatalyst for various energy and environmental applications. However, the photocatalytic efficiency of g-C3 N4 is still affected by its rapid charge recombination and sluggish electron-transfer kinetics. In this contribution, two-dimensionally protonated g-C3 N4 was employed as metal-free photocatalyst for water treatment and demonstrated 100 % of Escherichia coli within 4 h under irradiation with a 23 W light bulb. The introduction of protonation can modulate the surface charge of g-C3 N4 ; this enhances its conductivity and provides a "highway" for the delocalization of electrons. This work highlights the potential of conjugated polymers in antibacterial application.

Conducting Polyetheretherketone Nanocomposites with an Electrophoretically Deposited Bioactive Coating for Bone Tissue Regeneration and Multimodal Therapeutic Applications.

The use of polyetheretherketone (PEEK) has grown exponentially in the biomedical field in recent decades because of its outstanding biomechanical properties. However, its lack of bioactivity/osteointegration remains an unresolved issue toward its wide use in orthopedic applications. In this work, graphene nanosheets have been incorporated into PEEK to obtain multifunctional nanocomposites. Because of the formation of an electrical percolation network and the π-π* conjugation between graphene and PEEK, the resulting composites have achieved 12 orders of magnitude enhancement in their electrical conductivity and thereby enabled electrophoretic deposition of a bioactive/antibacterial coating consisting of stearyltrimethylammonium chloride-modified hydroxyapatite. The coated composite implant shows significant boosting of bone marrow mesenchymal stem cell proliferation in vitro. In addition, the strong photothermal conversion effect of the graphene nanofillers has enabled laser-induced heating of our nanocomposite implants, where the temperature of the implant can reach 45 °C in 150 s. The unique multifunctionality of the implant has also been demonstrated for photothermal applications such as enhancing bacterial eradication and tumor cell inhibition, as well as bone tissue regeneration in vivo. The results suggest the strong potential of our multifunctional implant in bone repair applications as well as multimodal therapy of challenging bone diseases such as osteosarcoma and osteomyelitis.

Construction of a Mesoporous Polydopamine@GO/Cellulose Nanofibril Composite Hydrogel with an Encapsulation Structure for Controllable Drug Release and Toxicity Shielding.

The development of intelligent and multifunctional hydrogels having photothermal properties, good mechanical properties, sustained drug release abilities with low burst release, antibacterial properties, and biocompatibility is highly desirable in the biomaterial field. Herein, mesoporous polydopamine (MPDA) nanoparticles wrapped with graphene oxide (GO) were physically cross-linked in cellulose nanofibril (CNF) hydrogel to obtain a novel MPDA@GO/CNF composite hydrogel for controllable drug release. MPDA nanoparticles exhibited a high drug loading ratio (up to 35 wt %) for tetracycline hydrochloride (TH). GO was used to encapsulate MPDA nanoparticles for extending the drug release time and reinforcing the physical strength of the obtained hydrogel. The mechanical strength of the as-fabricated MPDA@GO/CNF composite hydrogel was five times greater compared to that of the pure CNF hydrogel. Drug release experiments demonstrated that burst release behavior was significantly reduced by adding MPDA@GO. The drug release time of the MPDA@GO/CNF composite hydrogel was 3 times and 7.2 times longer than that of the polydopamine/CNF hydrogel and pure CNF hydrogel, respectively. The sustained and controlled drug release behaviors of the composite hydrogel were highly dependent on the proportion of MPDA and GO. Moreover, the rate of drug release could be accelerated by near-infrared (NIR) light irradiation and pH value change. The drug release kinetics of the as-prepared composite hydrogel was well described by the Korsmeyer-Peppas model, and the drug release mechanism of TH from the composite hydrogel was anomalous transport. Importantly, this carefully designed MPDA@GO/CNF composite hydrogel showed good biocompatibility through an in vitro cytotoxicity test. In particular, the toxicity of GO was well shielded by the CNF hydrogel. Therefore, this novel MPDA@GO/CNF composite hydrogel with an encapsulation structure for controllable drug release and toxicity shielding of GO could be used as a very promising controlled drug delivery carrier, which may have potential applications for chemical and physical therapies.

Biocide mechanism of highly efficient and stable antimicrobial surfaces based on zinc oxide-reduced graphene oxide photocatalytic coatings.

Highly efficient photoactive antimicrobial coatings were obtained using zinc oxide-reduced graphene oxide nanocomposites (ZnO-rGO). Their remarkable antibacterial activity and high stability demonstrated their potential use for photoactive biocide surfaces. The ZnO-rGO nanocomposites were prepared by the sol-gel technique to create photocatalytic surfaces by spin-coating. The coatings were deeply characterised and several tests were performed to assess the antibacterial mechanisms. rGO was homogeneously distributed as thin sheets decorated with ZnO nanoparticles. The surface roughness and the hydrophobicity increased with the incorporation of graphene. The ZnO-rGO coatings exhibited high activity against the Gram-positive bacterium Staphylococcus aureus. The 1 wt% rGO coated surfaces showed the highest antibacterial effect in only a few minutes of illumination with up to 5-log reduction in colony forming units, which remained essentially free of bacterial colonization and biofilm formation. We demonstrated that these coatings impaired the bacterial cells due to cell membrane damage and intracellular oxidative stress produced by the photogenerated reactive-oxygen species (ROS). The enhancement of the ZnO photocatalytic performance upon rGO incorporation is due to the increased detected generation of hydroxyl radicals, attributed to the reduction of electron-hole pair recombination. This intimate contact between both components also conveyed stability against zinc leaching and improved the coating adhesion.

Co3O4 nanoparticles/graphitic carbon nitride heterojunction for photoelectrochemical aptasensor of oxytetracycline.

As a broad-spectrum tetracycline antibiotic, the overuse of oxytetracycline (OTC) causes antibiotics residues in the environment and seriously threats to human health owing to effective antibacterial properties. Thus, it is particularly important to design a photoelectrochemical (PEC) aptasensor to detect OTC with excellent performance. Herein, we developed a selective and stable PEC aptasensor of OTC on the basis of Co3O4 nanoparticles (Co3O4 NPs)/graphitic carbon nitride (g-CN) heterojunction, used as PEC active materials. The Co3O4 NPs were successfully grown on the g-CN via grinding and calcining mixture of Co3O4 precursors and bulk g-CN. The Co3O4/g-CN heterojunction with improved light utilization and promoted electrons/holes separation capability can exhibit higher PEC signal than that of g-CN. In order to implement the purpose of specific recognition, OTC-aptamer was introduced into modified electrode to construct highly selective PEC aptasensor for OTC determination, which can possess wide linear range (0.01-500 nM) with low detection limit (3.5 pM, S/N = 3). This PEC aptasensor platform with excellent selectivity and high stability can provide a practical application in the field of water monitoring.

Magnetically Recoverable TiO2/SiO2/γ-Fe2O3/rGO Composite with Significantly Enhanced UV-Visible Light Photocatalytic Activity.

In this paper, we report the preparation of a new composite (TiO2/SiO2/γ-Fe2O3/rGO) with a high photocatalytic efficiency. The properties of the composite were examined by different analyses, including X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), photoluminescence (PL), UV-Visible light diffuse reflectance spectroscopy, Fourier transform infrared spectroscopy (FTIR), Raman, vibrating-sample magnetometer (VSM), and nitrogen gas physisorption (BET) studies. The photocatalytic efficiency of the proposed composite was evaluated by the degradation of methylene blue under UV and visible light, and the results were compared with titanium dioxide (TiO2), where degradation increased from 30% to 84% and 4% to 66% under UV and visible light, respectively. The significant increase in photocatalytic activity may be explained by the higher adsorption of dye on the surface of the composite and the higher separation and transfer of charge carriers, which in turn promote active sites and photocatalytic efficiency.

A triple-channel sensing array for protein discrimination based on multi-photoresponsive g-C3N4.

Graphitic carbon nitride (g-C3N4) as an outstanding photoresponsive nanomaterial has been widely used in biosensing. Other than the conventional single channel sensing mode, a triple-channel sensing array was developed for high discrimination of proteins based on the photoresponsive g-C3N4. Besides the photoluminescence and Rayleigh light scattering features of g-C3N4, we exploit the new photosensitive colorimetry of g-C3N4 as the third channel optical input. The triple-channel optical behavior of g-C3N4 can be synchronously changed after interaction with the protein, resulting in the distinct response patterns related to each specific protein. Such a triple-channel sensing array is demonstrated for highly discriminative and precise identification of nine proteins (hemoglobin, trypsin, lysozyme, cytochrome c, horseradish peroxidase, transferrin, human serum albumin, pepsin, and myoglobin) at 1 µM concentration levels with 100% accuracy. It also can discriminate proteins being present at different concentration and protein mixtures with different content ratios. The practicability of this sensor array is validated by high accuracy identification of nine proteins in human urine samples. This indicates that the array has a great potential in terms of analyzing biological fluids. Graphic abstract .

Investigation on photo-induced mechanistic activity of GO/TiO2 hybrid nanocomposite against wound pathogens.

Pathogenic microorganism delays wound-healing process by causing infection. In recent years, researchers have developed various kinds of photo-active nanomaterials with enhanced antibacterial properties. This work focus on the preparation of graphene oxide and TiO2 nanocomposites (GO/TiO2) as a visible light-induced high efficiency antibacterial material. The hydrothermal method was used for the synthesis of GO/TiO2 nanocomposites at 180 oC for 3 h with different loading percentages of GO (10, 20, 30, 40 and 50 wt. %). The systematic characterization tools including X-ray diffraction analysis, FT-IR, UV-vis, Raman and TEM which were used to understand the physicochemical properties of the prepared GO/TiO2 nanocomposites. Furthermore, GO/TiO2 nanocomposites were used as photocatalytic active materials against wound infection-causing bacteria in the presence of visible light irradiation. The possible antibacterial mechanism under presence and absence of light were depicted. The antibacterial mechanism of the GO/TiO2 nanocomposite was investigated on wound infection-causing bacteria such as Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Enterococcus faecalis. The high hemocompatibility and the cellular biocompatibility of the nanocomposite aids in using it for wound-healing application. Overall, the results suggest that the GO/TiO2 nanocomposite could be developed as a photo-active nanomaterial against pathogenic microorganisms that are present in wound.

NIR-Driven Water Splitting H2 Production Nanoplatform for H2-Mediated Cascade-Amplifying Synergetic Cancer Therapy.

As a newly emerging treatment strategy for many diseases, hydrogen therapy has attracted a lot of attention because of its excellent biosafety. However, the high diffusivity and low solubility of hydrogen make it difficult to accumulate in local lesions. Herein, we develop a H2 self-generation nanoplatform by in situ water splitting driven by near-infrared (NIR) laser. In this work, core-shell nanoparticles (CSNPs) of NaGdF4:Yb,Tm/g-C3N4/Cu3P (UCC) nanocomposites as core encapsulated with zeolitic imidazolate framework-8 (ZIF-8) modified with folic acid as shell are designed and synthesized. Due to the acid-responsive ZIF-8 shell, enhanced permeability and retention (EPR) effect, and folate receptor-mediated endocytosis, CSNPs are selectively captured by tumor cells. Upon 980 nm laser irradiation, CSNPs exhibit a high production capacity of H2 and active oxygen species (ROS), as well as an appropriate photothermal conversion temperature. Furthermore, rising temperature increases the Fenton reaction rate of Cu(I) with H2O2 and strengthens the curative effect of chemodynamic therapy (CDT). The excess glutathione (GSH) in tumor microenvironment (TME) can deplete positive holes produced in the valence band of g-C3N4 in the g-C3N4/Cu3P Z-scheme heterojunction. GSH also can reduce Cu(II) to Cu(I), ensuring a continuous Fenton reaction. Thus, a NIR-driven H2 production nanoplatform is constructed for H2-mediated cascade-amplifying multimodal synergetic therapy.

Bridge between Temperature and Light: Bottom-Up Synthetic Route to Structure-Defined Graphene Quantum Dots as a Temperature Probe In Vitro and in Cells.

Owing to their unique superiorities in chemical and photoluminescence (PL) stability, low toxicity, biocompatibility, and easy functionalization, graphene quantum dots (GQDs) are widely used in cell imaging, probes, and sensors. However, further development and deeper research of GQDs are restricted by their imprecise and complex structure and accompanying controversial PL mechanism. In this work, two kinds of structure-defined water-soluble GQDs, with different oxidation degrees, are synthesized from molecules using bottom-up syntheses methods. After being studied by a series of characterizations, their optical properties, functional groups, molecular weight, and structural information were obtained. The optical properties of GQDs could be optimized by controlling their oxidation degree. The PL mechanism of GQDs was investigated by comparing their structure and properties. Furthermore, robust, stable, and precise temperature probes were designed using the GQDs, which exhibited an excellent wide response range, covering the whole physiology temperature range, from 0 to 60 °C in water. Moreover, the GQDs were successfully applied as temperature-responsive fluorescence probes in the HeLa cell line. These works laid a solid foundation for further applications of GQDs as biological thermoprobes and selectively temperature detectors in vitro cellular and in vivo.