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Combining photothermal therapy (PTT) with chemodynamic therapy (CDT) is an efficacious strategy for cancer treatment. However, the hyperthermia-induced heat shock response and low Fenton reaction efficiency limited its clinical application. Here, we present self-assembled querce-tin-Fe3+nanoparticles (Qu-Fe NPs) for synergetic near-infrared (NIR) light-triggered low-temperature PTT (LTPTT) and glutathione (GSH)-activated CDT. Qu-Fe NPs had a broad absorption range extending to the NIR region and excellent photothermal conversion ability. After endocytosis into cancer cells, these NPs partially released Qu that downregulated the expression of heat shock protein 70, in turn allowing for LTPTT. Moreover, Qu-Fe NPs could deplete the overexpressed GSH in cancer cells, increasing their sensitivity to reactive oxygen species. Meanwhile, Fe3+could be reduced to Fe2+, which can react with endogenous H2O2to generate hydroxyl radicals to achieve CDT. Heat generated by PTT could further accelerate the Fenton reaction in CDT, thus resulting in the synergistic effects between LTPTT and CDT. Both in vitroand in vivoresults showed that Qu-Fe NPs could effectively inhibit tumor growth. This work presents a new approach for achieving mutually reinforced, synergetic NPs that can be used for LTPTT/CDT combination therapy.

Clinical phototheranostic agents suffer from low absorption in near-infrared (NIR) region, decreasing singlet oxygen quantum yield (1O2QY) caused by aggregation in water, and low photothermal conversion efficiency (PCE), all of which are factors weakening their phototheranostic efficacy. Herein, we designed and synthesized a donor-acceptor-donor (D-A-D) structured boron-dipyrromethene derivative (B-2TPA) which exhibited NIR absorption and fluorescence. After being encapsulated in amphiphilic distearoyl phosphoethanolamine polyethyleneglycol 2000 (DSPE-PEG-2000), the water-soluble B-2TPAnanoparticles (NPs) had increasing 1O2QY (6.7%) due to the intermolecular aggregation-induced decrease in the energy gap between singlet and triplet excited states. Moreover, the quenched fluorescence and stable twisted intramolecular charge transfer in aggregates further increased the PCE of B-2TPANPs to 60.1%. In vitroand in vivostudies confirmed that B-2TPANPs could be used in NIR fluorescence and photoacoustic imaging-guided synergistic photodynamic and photothermal therapy in tumor treatment.

Multimodal imaging-guided combinational phototherapies triggered by a single near-infrared (NIR) laser are highly desirable. However, their development is still a big challenge. Herein, we have developed an “acceptor–donor–acceptor′–donor–acceptor” structured organic phototheranostics (Y16-Pr) with strong light-harvesting ability in the NIR region. After being modified with polyethylene glycol (PEG), the obtained biocompatible nanoparticles (Y16-Pr-PEG NPs) could conduct NIR-II fluorescence imaging (FLI) and photoacoustic imaging (PAI) and perform photothermal therapy (PTT) and photodynamic therapy (PDT) simultaneously. Notably, Y16-Pr-PEG NPs showed an impressive photothermal conversion efficiency (PCE) of 82.4% under 808 nm laser irradiation. The irradiated NPs could also produce hydroxyl radicals (•OH) and singlet oxygen (1O2) for type I and type II PDT, respectively. In vivo and in vitro experiments revealed that the Y16-Pr-PEG NPs significantly inhibit tumor cell growth without apparent toxic side effects under laser irradiation. Overall, the single-laser-triggered multifunctional phototheranostic Y16-Pr-PEG NPs can achieve NIR-II FLI/PAI-guided synergistic PTT/PDT against tumors.

Multi-modal imaging-guided synergistic photodynamic therapy (PDT) and photothermal therapy (PTT) show great benefits in cancer treatment. The phototheranostics with near-infrared (NIR) absorption, high reactive oxygen species (ROS) generation and photothermal conversion efficiency is highly desirable. Here, we designed and synthesized an “acceptor-donor-acceptor” (A-D-A) structured molecule named IDCIC, with strong absorbance in the NIR region. We further prepared IDCIC into water-soluble nanoparticles (NPs) by wrapping with 1,2-distearoylsn-glycero-3-phosphoethanolamine-N-[(polyethylene glycol)-2000]-amine (DSPE-PEG2000-NH2). The obtained IDCIC NPs show an NIR absorption peak at 760 nm and an NIR-II fluorescence spectrum peak at ∼1000 nm with a fluorescent quantum yield of 1.2%, enabling them excellent photoacoustic and NIR-II fluorescent imaging capabilities. Moreover, IDCIC NPs could simultaneously generate singlet oxygen (with a quantum yield of 9.1%), hydroxyl radicals (·OH) and heat (with a photothermal conversion efficiency of 78.9%) under 808-nm laser irradiation. Based on the above-mentioned properties, IDCIC NPs were used for dual-modal imagingguided synergistic photodynamic/photothermal therapy of cancer.

A tetraphenylethylene-based aggregation-induced emission molecule (BT-5) bearing two positively charged imidazolium pendants and an alkyl chain (C10H20) was designed as a fluorescence turn-on probe for detecting lipopolysaccharide (LPS) in injectable water sample. Upon addition of LPS, the BT-5aqueous solution showed a concentration-dependent increase in fluorescence spectra. Moreover, BT-5displayed a high selectivity to LPS in the presence of polysaccharide, surfactants, cations, anions, and several amino acids that may exist in injectable water samples with a low limit of detection of 120 pM, which is much lower than that of previous reports. The sensing procedure was observed by the naked eye under the 365 nm UV light irradiation. The outstanding sensing performance of BT-5was demonstrated to originate from the combination of electrostatic and hydrophobic interactions between BT-5and LPS.

Combining phototherapy and chemotherapy has been considered a promising modality for cancer therapy due to their synergistic effect. Herein, we developed three D-π-A-structured boron dipyrromethenes (BODIPYs) (named as B-B, B-C, and B-C-Pt). Due to their enlarged π-conjugated structure and high intramolecular charge transfer effect, the synthesized BODIPYs had photothermal conversion capability, and their absorption and fluorescence spectra were red-shifted. The cisplatin-appended BODIPY (B-C-Pt) exhibited good singlet oxygen (1O2) generation ability and near infrared (NIR) absorption and fluorescence (λAbs= 748 nm, λEm= 947 nm). After being encapsulated by distearoyl phosphoethanolamine polyethyleneglycol 2000 (DSPE-PEG-2000), which could inhibit the H-aggregation of B-C-Pt, the absorption and fluorescence of the obtained B-C-Ptnanoparticles (NPs) were red-shifted to 762 and 985 nm, respectively. The 1O2quantum yield and photothermal conversion efficiency of the B-C-PtNPs were 4.0% and 40.6%, respectively. Moreover, B-C-PtNPs had chemotherapeutic efficacy due to the presence of cisplatin. In vitroand in vivostudies further demonstrated that B-C-PtNPs had synergistic therapeutic efficacy. Together, B-C-PtNPs could be employed in NIR II fluorescent and photoacoustic imaging-guided synergistic phototherapy and chemotherapy for cancer treatment.

Spermine is an indicator of the meat freshness, and thus, developing efficient approaches with low cost for spermine detection is highly desirable. Here, we report a fluorometric probe for the sensitive and selective detection of spermine. This probe is composed of blue fluorescent carbon dots (CDs) and red fluorescent cadmium telluride quantum dots (CdTe QDs), in which CdTe QDs act as the response signal and CDs as the internal reference. The red fluorescence of CdTe QDs is efficiently quenched, while the CD fluorescence remained constant with the addition of spermine, leading to a distinguishable fluorescent color variation of the probe solution from shallow pink to blue. This probe can selectively identify spermine from other organic amines with a low limit of detection (76 nM). Furthermore, a ratiometric fluorescent paper is developed and employed as an on-site, rapid-responsive, and cost-effective method for real time and visually monitoring the freshness of pork.

Designing and synthesizing nanomedicines with multi-modal tumor therapeutic capabilities is the key to cancer treatment. Herein, we prepared MICG nanoparticles (NPs) by assembling glucose oxidase (GOx) and indocyanine green (ICG) with manganese carbonate (MnCO3) NPs for starvation therapy cascaded chemodynamic therapy, enhanced phototherapy and immune activation. In MICG NPs, the GOx consumes intratumoral glucose resulting in starvation therapy, and simultaneously produces H2O2and decreases pH in tumor. The intensified acidic tumor environment promotes the decomposition of MnCO3NPs to release Mn2+. The Mn2+further catalyzes H2O2to generate hydroxyl radical for chemodynamic therapy. While ICG can generate singlet oxygen (1O2) and heat to kill cancer cells through phototherapy mechanism. The hydroxyl radical and 1O2will further accelerate the oxidative stress, intensify immunogenic cell death, induce dendritic cell maturation, and thus activate systemic immunity. This work provides a new therapeutic platform for combining therapy of tumor.

Positively charged water-soluble polythiophene (PT0) that could self-assemble into nanoparticles in pure water solution was designed and synthesized. PT0exhibited high photostabilities and pH stabilities, excellent biocompatibility, strong 1O2generation capability, and large two-photon absorption cross sections. Moreover, we showed that the fluorescence of PT0was unaffected by the interference of biomolecules and metal ions. As an example application, PT0was demonstrated to be capable of simultaneous cell imaging and photodynamic therapy under either one-photon or two-photon excitation modes.

Various phototheranostics have recently been developed for phototherapy. Through proper molecular design, the photochemical and photophysical properties of these phototheranostics can be promoted. Herein, an acceptor-donor-acceptor (A-D-A)-structured dye, BTP-4F-DMO, was synthesized and prepared into water-soluble nanoparticles (NPs). The obtained BTP-4F-DMO NPs had strong absorption from 650 nm to 850 nm and a fluorescence emission peak at ∼900 nm that tailed to ∼1100 nm. The NPs showed a superhigh photothermal conversion efficiency of 90.5% ± 5% and could simultaneously generate •OH and 1O2with a 1O2generation quantum yield of 4.6% under 808 nm laser irradiation. Due to these advanced properties, BTP-4F-DMO NPs can switch the role of autophagy from pro-survival to pro-death, thereby further promoting cancer cell death. These features make BTP-4F-DMO NPs a promising multifunctional phototheranostic agent for NIR-II fluorescence/photoacoustic dual-mode imaging-guided synergetic photodynamic/photothermal therapy. In general, this work provides a strategy for expanding the biomedical applications of organic A-D-A-structured phototheranostics.

Nitrogen and sulfur codoped carbon dots (CDs) were prepared from garlic by a hydrothermal method. The as-prepared CDs possess good water dispersibility, strong blue fluorescence emission with a fluorescent quantum yield of 17.5%, and excellent photo and pH stabilities. It is also demonstrated that the fluorescence of CDs are resistant to the interference of metal ions, biomolecules, and high ionic strength environments. Combining with low cytotoxicity properties, CDs could be used as an excellent fluorescent probe for cellular multicolor imaging. Moreover, the CDs were also demonstrated to exhibit favorable radical scavenging activity.

Overuse of oxytetracycline (OTC) in livestock farming can cause environmental water pollution, risking human health. It is essential to exploit efficient, fast, and sensitive measures to sense OTC in environmental water samples. In this study, a ratiometric fluorescence probe consisted of blue-fluorescent carbon dots (CDs) and Eu3+was constructed to detect OTC sensitively and selectively. Upon the addition of OTC, bright red fluorescence was generated due to the aggregation of Eu3+, and the intensity of blue fluorescence of CDs reduced because of the inner filter effect between OTC and CDs. Under 365 nm UV light irradiation, the increasing of OTC concentration from 0 to 10 μM resulted a transformation of probe solution fluorescence color from blue to pick. This CDs–Eu3+hybrid probe also performed a high selectivity for OTC with minimal interference containing various antibiotics, cations, and amino acids. Importantly, the probe demonstrated a low detection limit of 9.6 nM and a satisfactory recovery efficiency for OTC detection in river and tap water.

Photothermal therapy (PTT) has inherent advantages in the treatment of hypoxic tumors due to its optically controlled selectivity on tumor ablation and oxygen-independent nature. The subcellular organelle-targeting capability and photothermal conversion efficiency (PCE) at near-infrared (NIR) wavelength are the key parameters in the assessment of the photothermal agent (PTA). Here, we report that carbon dots (CDs) prepared by the hydrothermal treatment of coronene derivatives show a high PCE of 54.7% at 808 nm, which can be attributed to the narrow band gap and the presence of amounts of continuous energy bands on CDs. Moreover, the vibrations in the layered graphite structures of the CDs also increase the rate of nonradiative transition and thus enhance the PCE. Furthermore, the CDs also possess excellent photostability, biocompatibility, and cell penetration capability and could mainly accumulate in the lysosomes. These experiment results have proved that the CDs are suitable as an efficient NIR light-triggered PTA for efficient PTT against cancer.

Benzoyl peroxide (BPO) has been added in wheat flour because of its bleaching effect. However, the abnormal used BPO has caused increasing concern due to its strong oxidization capability which may have adverse effects on living organisms. Herein, we present a carbon dot (CD)-based fluorescent and colorimetric probe for visually, sensitively and selectively sensing BPO. The addition of BPO could quench the red fluorescence of CDs peaked at 622 and 677 nm, and decrease the absorbance at 613 nm, while increase the absorbance at 450 nm, resulting in a fluorescence turn-off and colorimetric spectral response. Moreover, the CDs had short response time of 10 min and high sensitivity towards BPO with a low limit of detection of 28 nmol/L. The applicability of the CDs in detecting BPO in wheat, noodle and starch samples was further demonstrated, and good recovery results were obtained.

CDs with stable fluorescence, excellent cell permeability capacity and high photothermal conversion efficiency of 42.4% were prepared. Moreover, the CDs have intrinsic anti-fungal activity and high pesticide loading efficiency. The pesticide-loaded CDs show improved anti-fungal activity and a low EC50 value, as compared with the pesticide.

As an emerging clinical modality for cancer treatment, photodynamic therapy (PDT) takes advantage of the cytotoxic activity of reactive oxygen species (ROS) that are generated by light irradiating photosensitizers (PSs) in the presence of oxygen (O2). However, further advancements including tumor selectivity and ROS generation efficiency are still required. Substantial efforts are devoted to design and synthesize smart PSs with optimized properties for achieving a desirable therapeutic efficacy. This review summarizes the recent progress in developing intelligent PSs for efficient PDT, ranging from single molecules to delicate nanomaterials. The strategies to improve ROS generation through optimizing photoinduced electron transfer and energy transfer processes of PSs are highlighted. Moreover, the approaches that combine PDT with other therapeutics (e.g., chemotherapy, photothermal therapy, and radiotherapy) and the targeted delivery in cancer cells or tumor tissue are introduced. The main challenges for the clinical application of PSs are also discussed. This reviewhighlights the strategies to enhance the reactive oxygen species generation through optimizing photoinduced electron transfer and energy transfer processes of photosensitizers (PSs). The approaches that combine photodynamic therapy with other therapeutics (e.g., chemotherapy, photothermal therapy, and radiotherapy) and the targeted delivery in cancer cells or tumor tissue are introduced. The main challenges for the clinical application of PSs are also discussed.