Water-soluble Dye Research Articles

Congo red induces trans-priming to UV-B radiation in Metarhizium robertsii

Metarhizium spp. is used as a biocontrol agent but is limited because of low tolerance to abiotic stress. Metarhizium robertsii is an excellent study model of fungal pathogenesis in insects, and its tolerance to different stress conditions has been extensively investigated. Priming is the time-limited pre-exposure of an organism to specific stress conditions that increases adaptive response to subsequent exposures. Congo red is a water-soluble azo dye extensively used in stress assays in fungi. It induces morphological changes and weakens the cell wall at sublethal concentrations. Therefore, this chemical agent has been proposed as a stressor to induce priming against other stress conditions in entomopathogenic fungi. This study aimed to evaluate the capacity of Congo red to induce priming in M. robertsii. Conidia were grown on potato dextrose agar with or without Congo red.The tolerance of conidia produced from mycelia grown in these three conditions was evaluated against stress conditions, including osmotic, oxidative, heat, and UV-B radiation. Conidia produced on medium supplemented with Congo red were significantly more tolerant to UV-B radiation but not to the other stress conditions assayed. Our results suggest that Congo red confers trans-priming to UV-B radiation but not for heat, oxidative, or osmotic stress.

Patterning of Molecules/Ions via Reverse Micelle Vessels by Nanoxerography.

Precise patterning of molecules/ions in the nanometer scale is a crucial but challenging technique for the fabrication of advanced functional nanodevices. We developed a robust method to print molecules/ions into arbitrarily defined patterns with sub-20 nm precision assisted by reverse micelles. The reverse micelle, serving as a nano-sized vessel, can load molecules/ions and then be patterned onto the predefined positions by electrostatic attraction. The number of molecules/ions on each spot, the spot spacing, and pattern shapes can be flexibly adjusted, reaching 10 nm position accuracy, 30 nm spot size, and 100 nm spot spacing (>250,000 DPI). Then, water-soluble dye molecules, protein molecules, and chloroaurate ions were loaded in the micelles and successfully patterned into nanoarrays, which provides an important platform for the convenient, flexible, and robust fabrication of functional molecule/ion-based nanodevices, such as biochips, for high-throughput and ultrasensitive analysis.

Interfacially Polymerized β-Cyclodextrin Film for Rapid Removal of Organic Dyes.

Porous cyclodextrin-based polymers are widely used for the rapid removal of organic pollutants in water. Traditional cyclodextrin-based polymers are prepared in the organic phase, which is time consuming and costly. Herein, a novel cyanuricchloride (TCT) cross-linked porous β-cyclodextrin-based thin-film composite membrane is designed in the aqueous phase by interfacial polymerization. A self-standing TCT-CDP film is formed instantly at the surface of water phase at room temperature. Several different water-soluble organic dyes such as Methylene Blue, Neutral Red, Auramine, Brilliant Green, and Crystal Violet are selected for rejection study with TCT-CDP membrane. The effective rejection of TCT-CDP membrane for typical dyes is up to 99%, indicating TCT-CDP membrane exhibit excellent selectivity for separation of organic dyes from water.

Green synthesis of graphene-oxide based nanocomposites for efficient removal of methylene blue dye from wastewater

Water-soluble dyes are a common problem in wastewater treatment, requiring highly efficient methods for removal. In this study, novel sustainable adsorbents made from graphene-oxide (GO) and other materials, such as eggshell-derived calcium oxide nanoparticles (CaONPs-ES), fish bone calcium oxide nanoparticles (CaONPs-FB), and durian shell activated carbon (DSAC) were synthesized, characterized, and demonstrated for soluble dye removal from wastewater. Fermented maize grain extract (MES) was used as a green cross-linker in the synthesis process. The resulting nanocomposites, GO@CaONPs-ES/DSAC and GO@CaONPs-FB/DSAC, showed promising adsorption capabilities for methylene blue (MB) dye removal from aqueous environments. The prepared nanocomposites (GO@CaONPs-ES/DSAC and GO@CaONPs-FB/DSAC) were characterize using state-of-art instrumental techniques. The BET measurement revealed that the nanocomposites surface areas were enhanced due to the cross-linking phenomenon, improving their adsorption capability towards MB dye treatment. The adsorption data of GO@CaONPs-FB/DSAC and GO@CaONPs-ES/DSAC was well fitted to the Harkins-Jura and Freundlich models, respectively. The maximum sorption capacities of GO@CaONPs-ES/DSAC and GO@CaONPs-FB/DSAC were 1274.5 and 689.7 mg/g, respectively. The MB dye removal mechanism was driven by π-π interaction, hydrogen bonding, electrostatic attraction and physical interactions and the adsorption process of the nanocomposites followed pseudo-second-order kinetics. The adsorptive performance of the nanocomposites was stable, showing ∼96.45 % and ∼85.18 % after 10 successive cycles for GO@CaONPs-ES/DSAC and GO@CaONPs-FB/DSAC respectively. Cost evaluation revealed that bulk synthesis of GO@CaONPs-ES/DSAC and GO@CaONPs-FB/DSAC nanocomposites is cost-effective for treating large quantities of MB contaminated water and other potential dyes as well. Finally, the independent and synergetic contributions between pH, adsorbent dosage and temperature on MB removal by GO@CaONPs-ES/DSAC and GO@CaONPs-FB/DSAC were studied and optimized by central composite design (CCD) an aspect of the response surface methodology (RSM). Finally, this study suggests that the novel green cross-linking approach has a significant impact in enhancing the adsorptive performances of the developed nanocomposites to effectively capture MB from aqueous environment.

Intensification of dying of silk and cotton-silk fabrics with water-soluble dyes in the presence of chitosan

The results of the study of the effects of textile excipients are striking for the intensification of the processes of dyeing silk and mixed fabrics with active dyes. For the first time, a technique has been developed for using chitosan isolated from dead bees Apis Mellifera as an intensifier. It was found that treatment with chitosan leads to an increase in their sorption capacity and the appearance of centers of charge in silk and cellulose fibers. A certain nature of the bond and the chemical mechanism of action in the fiber-chitosan-dye system, as well as the effect of intensifiers on the degree and amount of fixation of active dyes on the fiber. The article uses modern physical and chemical research methods: IR and UV spectroscopy, scanning electron microscopy (SEM), standard methods for determining the physical and mechanical properties, as well as color indicators of the quality of dyed fabrics. The practical significance of the results of the study is explained by the fact that the dyeing of silk and cotton-silk fabrics in the presence of chitosan improves the color characteristics of the fabric, reduces the use of imported dyes and reduces the consumption of chemical reagents.

KINETIC SPECTROPHOTOMETRIC DETERMINATION OF TAPENTADOL

A simple, inexpensive, accurate and sensitive spectrophotometric method and kinetic assay have been established to determine tapentadol in pure form, tablets and urine samples. The method is based on the reaction of tapentadol with ferric ions in an acidic solution in the presence of ferricyanide to give water-soluble Prussian blue dye with a maximum absorption wavelength of 735 nm, with a maximum reaction time of 40 minutes. Several experimental factors affect the colour intensity and stability time approaches. The reaction was identified as a first-order pseudo-reaction by calculating the initial rate, and the results of the fixedtime method (at 30 min) are more suitable for quantification and used to construct the calibration curves. The correlation between concentration and absorbance was linear. Moreover, varies from 2 to 12 μg/mL and has a detection limit of 0.1737 μg/mL and a quantification limit of 0.5264 μg/mL. The molar absorption coefficient and Sandel sensitivity were 1.5484 x 10 4 L.mol-1.cm-1 and 0.01430 μg.cm-2, respectively. A comparison of spectrophotometric data with a well-established fixed time kinetic demonstrated that the fixed time technique offers good accuracy, precision, low detection and quantification limitations, and is time efficient. These procedures were effectively used to analyze tapentadol in its pure form, tablet form, and urine sample, which were not observed in literature before

A fast, efficient, inexpensive and green way to outdoor photopolymerization

A series of environmentally friendly photoinitiating systems operating under mild conditions of visible light (Vis-PIs) were tested for vinyl polymerization using sunlight as a free of charge radiation source. These Vis-PIs based on water soluble xanthene dyes showed good performances after deaerating with an inert gas, obtaining colorless polymers with gravimetric yields up to 80–90% after short irradiation times (2–15 min). Aqueous solutions of the materials were highly viscous and viscosimetric measurements yielded molecular weights up to 106. Surprisingly, the evaluated Vis-PIs also worked successfully under ambient air atmosphere, obtaining similar polymer yields in the same irradiation times. Photolysis experiments and transient spectroscopy were used to shed light on the mechanism of the process, allowing both triplets and radicals formation of the dyes to be identified even in the presence of air. The kinetics of photopolymerization was studied following the monomer conversion at several irradiation times by FTIR. The results were interpreted based on kinetic data collected as competitive quenching mechanisms between the co-initiator and oxygen for the excited dyes. The present report represents a breakthrough in the search for fast, efficient and inexpensive Vis-PIs with low ecological impact, which can be very useful in outdoor coating applications among others.

Single-Molecule Displacement Mapping Indicates Unhindered Intracellular Diffusion of Small (≲1 kDa) Solutes.

While fundamentally important, the intracellular diffusion of small (≲1 kDa) solutes has been difficult to elucidate due to challenges in both labeling and measurement. Here we quantify and spatially map the translational diffusion patterns of small solutes in mammalian cells by integrating several recent advances. In particular, by executing tandem stroboscopic illumination pulses down to 400 μs separation, we extend single-molecule displacement/diffusivity mapping (SMdM), a super-resolution diffusion quantification tool, to small solutes with high diffusion coefficients D of >300 μm2/s. We thus show that for multiple water-soluble dyes and dye-tagged nucleotides, intracellular diffusion is dominated by vast regions of high diffusivity ∼60-70% of that in vitro, up to ∼250 μm2/s in the fastest cases. Meanwhile, we also visualize sub-micrometer foci of substantial slowdowns in diffusion, thus underscoring the importance of spatially resolving the local diffusion behavior. Together, these results suggest that the intracellular diffusion of small solutes is only modestly scaled down by the slightly higher viscosity of the cytosol over water but otherwise not further hindered by macromolecular crowding. We thus lift a paradoxically low speed limit for intracellular diffusion suggested by previous experiments.

NIR-II Aza-BODIPY Dyes Bioconjugated to Monoclonal Antibody Trastuzumab for Selective Imaging of HER2-Positive Ovarian Cancer.

Using fluorescence-guided surgery (FGS) to cytoreductive surgery helps achieving complete resection of microscopic ovarian tumors. The use of visible and NIR-I fluorophores has led to beneficial results in clinical trials; however, involving NIR-II dyes seems to outperform those benefits due to the deeper tissue imaging and higher signal/noise ratio attained within the NIR-II optical window. In this context, we developed NIR-II emitting dyes targeting human epidermal growth factor receptor 2 (HER2)-positive ovarian tumors by coupling water-soluble NIR-II aza-BODIPY dyes to the FDA-approved anti-HER2 antibody, namely, trastuzumab. These bioconjugated NIR-II-emitting dyes displayed a prolonged stability in serum and a maintained affinity toward HER2 in vitro. We obtained selective targeting of HER2 positive tumors (SKOV-3) in vivo, with a favorable tumor accumulation. We demonstrated the fluorescence properties and the specific HER2 binding of the bioconjugated dyes in vivo and thus their potential for NIR-II FGS in the cancer setting.

Spectrophotometric Determination of Vitamin B1 (Thia min Hydrochloride)In Pharmaceutical Preparation by Coupling Reaction with Diazotized Sulfanilic acid.

A simple, accurate and sensitive spectrophotometric method for the determination of vitamin B1 (hiamin hydrochloride) in aqueous solution is described. The method is based on the diazotization of sulfanilic acid followed by coupling with thiamin hydrochloride in the presence of sodium hydroxide to form reddish-brown water soluble dye that is stable and has maximum absorption at ( )",u*: 490nm ).The molarabsorptivity and sandell sensitivity were 7.74 x103 L.mol-l.cm-r and 0.045pg.cm-l respectively. The procedure is developed for bulk thiamin hydrochloride and some of their pharmaceutical preparalions. The are accurate, precise and comparable to the standard method (British pharmacopoeia).

Towards a cost-effective modeling of fluorescence in the condensed phase

We propose a synergistic computational/experimental investigation of fluorescence spectra in aqueous solution. As a powerful tool to analyze and interpret experimental findings, we develop a reliable and cost-effective computational protocol, which is able to correctly describe the solute-solvent interactions which can highly affect the spectral signal. To this purpose, the model not only takes into account specific, strong hydrogen bonding interactions, but also the dynamical aspects of the solvation phenomenon in both the ground and, remarkably, excited state. The computational protocol is tested against the reproduction of experimentally measured spectra of representative water soluble fluorescent dyes. An almost perfect agreement is reported, thus confirming the reliability of the methodology, that paves the way for a cost-effective investigation of ES properties of solvated systems.

An indolizine squaraine-based water-soluble NIR dye for fluorescence imaging of multidrug-resistant bacteria and antibacterial/antibiofilm activity using the photothermal effect.

The majority of nosocomial infections are caused by bacteria with antimicrobial resistance and the formation of biofilms, such as implant-related bacterial infections and sepsis. There is an urgent need to develop new strategies for early-stage screening, destruction of multidrug-resistant bacteria, and efficient inhibition of biofilms. Organic dyes that absorb and emit in the near-infrared (NIR) region are potentially non-invasive, high-resolution, and rapid biological imaging materials. In this study, a non-toxic and biocompatible indolizine squaraine dye with water-solubilizing sulfonate groups (SO3SQ) is studied for bacterial imaging and photothermal therapy (PTT). PTT is efficient in eliminating microorganisms through local hyperthermia without the risk of developing drug-resistant bacteria. The optical properties of SO3SQ are studied extensively in phosphate-buffered saline (PBS). UV-Vis-NIR absorption spectra analysis shows a strong absorption between 650nm - 1000nm. SO3SQ allows for the wash-free fluorescence imaging of drug-resistant bacteria via NIR fluorescence imaging due to a "turn-on" fluorescence property of the dye when interacting with bacteria. Although SO3SQ exhibits no toxicity against both Gram-positive bacteria and Gram-negative bacteria, the PTT property of SO3SQ is efficient in killing bacteria as well as inhibiting and eradicating biofilms. PTT experiments demonstrate that SO3SQ reduces 90% of cell viability in bacterial strains under NIR radiation with a minimum inhibition concentration (MIC90) of >450μg/mL. The PTT property of SO3SQ can also inhibit biofilms (BIC90=1000-2000μg/mL) and eradicate both preformed young and mature biofilms (MBEC90=1500-2000μg/mL) as observed by crystal violet assays.

LECITHIN MICROEMULSIONS WITH GAC OIL AND TURMERIC ESSENTIAL OIL

It has been shown that water-in-oil microemulsions in lecithin–oleic acid–Vaseline oil–vegetable oil–essential oil–water systems can be obtained using the oil of a tropical plant, gac (Momordica cochinchinensis), and turmeric essential oil (Curcuma longa). Water (at least 6.5 wt %) can be incorporated into the microemulsions at a lecithin concentration in the organic phase of 20 wt %, a Vaseline oil-to-gac oil ratio of 1 : 1 (weight/weight), and an oleic acid-to-lecithin molar ratio of 0.2–0.8. Depending on the contents of water and lecithin, the hydrodynamic diameter of microemulsion droplets ranges from 3 to 21 nm. FTIR spectroscopy has been employed to show that, for the microemulsion with W = 14, the fraction of bulk (free) water in the droplets is 36.5 mol %, the fraction of hydration water (bound to polar groups of the surfactants) is 55.0 mol %, and the fraction of water trapped between hydrocarbon chains is 8.5 mol %. Using the dialysis method and a water-soluble dye Rhodamine C as a model, it has been shown that the rate of its transfer from the microemulsion to the physiological solution is 15.4 × 10–3 g/(m2 h). Approximately 3.2% of the dye has been found to be released over 6 h, thus making it possible to develop controlled drug release systems.

Green Synthesis and Photocatalytic Dye Degradation Activity of CuO Nanoparticles

The degradation of dyes is a difficult task due to their persistent and stable nature; therefore, developing materials with desirable properties to degrade dyes is an important area of research. In the present study, we propose a simple, one-pot mechanochemical approach to synthesize CuO nanoparticles (NPs) using the leaf extract of Seriphidium oliverianum, as a reducing and stabilizing agent. The CuO NPs were characterized via X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence (PL) and Fourier-transform infrared spectroscopy (FTIR). The photocatalytic activity of CuO NPs was monitored using ultraviolet-visible (UV-Vis) spectroscopy. The CuO NPs exhibited high potential for the degradation of water-soluble industrial dyes. The degradation rates for methyl green (MG) and methyl orange (MO) were 65.231% ± 0.242 and 65.078% ± 0.392, respectively. Bio-mechanochemically synthesized CuO NPs proved to be good candidates for efficiently removing dyes from water.

Synthesis of functionalized janus hybrid nanosheets for one-step construction of pickering emulsion and selective photodegradation of water-soluble dyes

Recently, Pickering emulsions stabilized by photocatalytic nanomaterials have become a hotspot in the field of catalysis due to their high interfacial activity. However, since most photocatalytic nanomaterials are extremely hydrophilic, using them as stabilizers is unconvenient for Pickering emulsions construction. Herein, a novel magnetic Janus nanosheets (JMPSN/α-FeOOH) with Janus SiO2 nanosheets as the carrier and iron oxyhydroxide (α-FeOOH) as the catalyst species, respectively, was successfully fabricated through a simple synthetic strategy, which could act as an environmental-friendly Pickering emulsion emulsifier and catalyst simultaneously. We demonstrated that JMPSN/α-FeOOH exhibited good emulsifying properties of various oil phases. Morever, JMPSN/α-FeOOH in the formed Pickering emulsion-based photocatalytic system displayed significantly enhanced photocatalytic efficiency in degradation of dyes as compared to traditional non-emulsified systems while maintaining the stability of Pickering emulsion under constant irradiation. JMPSN/α-FeOOH could also quickly respond to external magnetic fields so as to achieve rapid recovery of catalyst, and catalyst still showed high catalytic activity after many catalytic cycles. Finally, a convenient and promising synthesis strategy for preparing Janus catalyst with low toxicity was proposed, which provided a guidance on how to effectively use the emulsion system stabilized by Janus catalyst to improve the degradation efficiency of various pollutants.

Influence of manganese-substitution on adsorption properties of BiFeO3 onto the elimination of methyl orange

ABSTRACT Herein, the BiFeO3 was modified by substituting varying manganese (Mn) concentration to improve the efficacy of eliminating methyl orange (MO), a water-soluble carcinogenic azo dye was presented. To examine the structure, morphology and band gap characteristics of the as-synthesised Mn-BiFeO3 nanocatalyst were characterised using various techniques including XRD, FESEM with EDX, FTIR, UV-vis DRS, and BET. Subsequently, parameters affecting the removal performance, such as adsorbent dosage (0.02–0.10 g), initial dye concentrations (10–60 mg/L), initial pH (1–13), percentage mol of manganese substitution (0–30%), and reusability of the adsorbent, were examined in detail. The specific surface area increases with doping from 6.829 to 13.063 m2/g, leading to enhanced adsorption capacity of manganese-substituted BiFeO3 as opposed to pristine BiFeO3. Adsorption kinetics was found to follow the pseudo-second-order kinetic model, while the adsorption equilibrium data obeyed the Freundlich isotherm model with a maximum adsorption capacity of 25.2 mg/g at 298 K. Interestingly, the catalyst showed more than 95% adsorption even after three consecutive cycles and therefore could be a good candidate for wastewater remediation.

A fluorogenic method to directly observe transfer and distribution of influenza viral contents to target vesicles.

There is a long-standing interest in studying viral infection processes using bottom-up biophysical models to dissect various underlying molecular determinants. Fusion of enveloped viruses with cellular membranes and subsequent release of viral contents into the cytoplasm is a key event in the infection cycle. In case of influenza virus, fusion of the viral membrane is mediated by conformational changes of its surface protein hemagglutinin triggered by acidic pH within endosomes. Previously, content transfer assays have relied on fluorescence enhancement of an encapsulated self-quenched water-soluble dye upon fusion of the viral compartment with a target membrane. However these assays do not track the transfer of actual viral macromolecular contents, and suffer from drawbacks such as the need to use high concentration of the content dye which may have perturbative effects on the membranes. To overcome these limitations, we developed a method utilizing nucleic acid-binding dyes to directly observe the transfer of viral ribonucleoprotein complexes to target vesicles by total internal reflection fluorescence (TIRF) microscopy. The dyes were encapsulated within surface-tethered vesicles and the unlabeled virus particles were bound via sialic acid receptors. The fluorogenic nature of the dyes allowed background-free detection of fusion events when pH was dropped. We determined the kinetics of viral content transfer and found that it is slower than that of lipid mixing. We further employed a super-localization strategy to investigate to what extent the viral contents are transferred to the target vesicle through the fusion pore. Overall, our method allows observation of viral fusion events on a single-particle level and will provide the groundwork for development of biosensors for rapid quantification of fusogenic virus particles.

Neuroprotective Efficacy of Europinidin in Streptozotocin-Induced Memory Impairment by Modulation of Oxidative Stress, Inflammatory Mediators, and Cholinesterase Activity in Rats.

Oral acute toxicity studies were performed to evaluate the toxicological effects of europinidin in animals. In this study, four different animal groups (n = 6) were used. Group I was the normal control, group II was the STZ-induced diabetes control, group III was STZ + europinidin-treated (10 mg/kg), and group IV was STZ + europinidin-treated (10 mg/kg). The efficacy of europinidin at a dose of 10 mg/kg and 20 mg/kg was studied with single-dose administration of streptozotocin, which experimentally induced memory impairments in Wistar male rats for 38 days. The mean body weight and blood glucose levels were recorded at the initial and end of the study. The two behavioural paradigms (Y-maze and Morris water maze) were performed to evaluate spatial and working memory in rats. The biochemical parameters such as acetylcholinesterase, choline acetyltransferase, superoxide dismutase, glutathione transferase, malonaldehyde, catalase, and nitric oxide level as hallmarks of oxidative stress were measured. Additionally, the proinflammatory parameters were also determined to evaluate the neuroinflammatory responses associated with streptozotocin such as tumor necrosis factor-alpha (TNF-α) interleukin-1β (IL-1β), interleukin (IL-6), nuclear factor-kappa B (NF-ƙB), interleukin (IL-10), and nuclear factor-erythroid factor 2-related factor 2 (Nrf2) in the perfused brain. The rats in the europinidin-treated group exhibited a significant restoration of body weight and blood glucose level as compared with the streptozotocin control group. Furthermore, europinidin significantly modulated the spatial and working memory in rats, when assessed through behavioural paradigms. Streptozotocin caused a significant alteration in biochemical, neuronal enzymatic, and neuroinflammatory parameters, which were significantly restored to normal levels by europinidin. The present study attributed the neuroprotective efficacy of europinidin in experimental animal models by subsiding the several biomarkers of oxidative stress, neuroinflammation, and neuronal enzymatic activities.

Optimizing Axial and Peripheral Substitutions in Si-Centered Naphthalocyanine Dyes for Enhancing Aqueous Solubility and Photoacoustic Signal Intensity.

Photoacoustic imaging using external contrast agents is emerging as a powerful modality for real-time molecular imaging of deep-seated tumors. There are several chromophores, such as indocyanine green and IRDye800, that can potentially be used for photoacoustic imaging; however, their use is limited due to several drawbacks, particularly photostability. There is, therefore, an urgent need to design agents to enhance contrast in photoacoustic imaging. Naphthalocyanine dyes have been demonstrated for their use as photoacoustic contrast agents; however, their low solubility in aqueous solvents and high aggregation propensity limit their application. In this study, we report the synthesis and characterization of silicon-centered naphthalocyanine dyes with high aqueous solubility and near infra-red (NIR) absorption in the range of 850-920 nm which make them ideal candidates for photoacoustic imaging. A series of Silicon-centered naphthalocyanine dyes were developed with varying axial and peripheral substitutions, all in an attempt to enhance their aqueous solubility and improve photophysical properties. We demonstrate that axial incorporation of charged ammonium mesylate group enhances water solubility. Moreover, the incorporation of peripheral 2-methoxyethoxy groups at the α-position modulates the electronic properties by altering the π-electron delocalization and enhancing photoacoustic signal amplitude. In addition, all the dyes were synthesized to incorporate an N-hydroxysuccinimidyl group to enable further bioconjugation. In summary, we report the synthesis of water-soluble silicon-centered naphthalocyanine dyes with a high photoacoustic signal amplitude that can potentially be used as contrast agents for molecular photoacoustic imaging.

Water-soluble polymer brush-substituted squaraine NIR-II dye for efficient photothermal therapy.

Near-infrared II (NIR-II, 1000-1700 nm) fluorescence imaging has the advantages of low light scattering and weak biological autofluorescence compared with conventional NIR (600-900 nm) fluorescence imaging and can obtain a high signal-to-noise ratio in deeper biological tissues, as well as micron-level high resolution. A great deal of effort has been directed toward the construction of conjugated polymers for effective NIR-triggered fluorescence imaging (FI) and photothermal therapy (PTT) combined therapy. However, NIR-II fluorescent materials are mainly nanoparticles prepared by coprecipitation methods, and water-soluble NIR-II materials need to be further developed. In this paper, we synthesized novel water-soluble squaric acid nanoparticles (SQ-POEGMA) with low toxicity and excellent photostability by attaching a water-soluble oligomer (POEGMA) to the small molecule squaric acid through a click chemistry reaction. The photothermal conversion efficiency of SQ-POEGMA is 33% in vitro, which can effectively inhibit the growth of cancer cells with 94% tumor inhibition rate in vivo under 808 nm laser irradiation, while no appreciable side effects were observed.