Environmentally benign, bright luminescent carbon dots from IV bag waste and chitosan for antimicrobial and bioimaging applications.

Luminescent carbon dots have gained significant attention in various fields due to their unique optical properties and potential applications. Here, the study was aimed to propose a novel and sustainable approach for the synthesis of luminescent carbon dots (ICDs) using IV (Intravenous) medical bag waste. The ICDs were synthesized through a facile and cost-effective method that involved the carbonization of IV bag waste followed by surface functionalization with chitosan. The synthesized ICDs were characterized using UV-Visible spectrum (UV-Vis), Fourier Transform Infrared Spectroscopy (FT-IR), X-Ray Diffraction analysis (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The size of the ICDs is between 2 and 8 nm. The ICDs effectively inhibited the growth of both gram positive and gram negative bacterial strains with the inhibitory activity in the range of 11-14 mm and 12-18 mm, respectively. Results of antibiofilm activity of ICDs varying concentrations (50 and 100 µg/ml) showed that it effectively distorted the biofilm architecture and thereby validated its promising potentials. In vitro antioxidant activity showed remarkable DPPH radical scavenging potentials of ICDs (33.4%-70.1%). Results of MTT assay revealted that ICDs showed potent cytotoxic effect on HeLa cells in a dose dependant matter (25-400 µg/ml). Furthermore, when HeLa cells were excited at wavelengths of 380 nm, 440 nm and 540 nm, cell-imaging experiments using ICDs revealed the presence of blue, green, and red fluorescence. This innovative method not only addresses the issue of IV bag waste in a sustainable manner but also opens up exciting possibilities for the advancement of versatile carbon-based materials in the field of biomedicine.

Multifunctional natural derived carbon quantum dots from Withania somnifera (L.) - Antiviral activities against SARS-CoV-2 pseudoviron.

Natural carbon dots (NCQDs) are expediently significant in the photo-, nano- and biomedical spheres owing to their facile synthesis, optical and physicochemical attributes. In the present study, three NCQDs are prepared and optimized from Withania somnifera (ASH) by one-step hydrothermal (bottom-up) method: HASHP (without dopant), nitrogen doped HASHNH3 (surface passivation using ammonia) and HASHEDA (surface passivation with ethylenediamine). The HR-TEM images reveal that HASHP, HASNH3, HASHEDA are spherically shaped with 2.5 ± 0.5 nm, 4 ± 1 nm and 5 ± 2 nm particle size, respectively, whereas FTIR confirms the aqueous solubility and nitrogen doping. The XRD patterns ensure that the NCQDs are amorphous and graphitic in nature. Comparatively, HASHNH3 (32.5%) and HASHEDA (27.6%) portray better fluorescence quantum yield than HASHP (5.6%). The increase in quantum yield for the doped NCQDs can be attributed to the surface passivation using ammonia and ethylenediamine. Surface passivation plays a crucial role in enhancing the fluorescence properties of quantum dots. The introduction of nitrogen through ammonia and ethylenediamine provides additional electronic states, possibly reducing non-radiative recombination sites and hence boosting the QY. In addition, an antiviral study unveils the striking potential of surface passivated NCQDs to curb Covid-19 crises with around 85% inhibition of SARS-CoV pseudoviron cells, which is better in comparison to the non-doped NCQDs. Hence, to understand the paramount efficacy of these NCQDs, a hypothesis on their possible mechanism of action against Covid-19 is discussed.

Fabrication of MoS2 restrained magnetic chitosan polysaccharide composite for the photocatalytic degradation of organic dyes.

Chitosan (CS) polysaccharide is expected to exhibit greater ionic conductivity, which can be attributed to its increased amino group content when it is blended with different semiconducting materials. Herein, the work used this conducting ability of chitosan and prepared a heterogeneous MoS2-induced magnetic chitosan (MF@CS) composite via the co-precipitation method, which was used to scrutinize the catalytic performance with Methylene Blue (MB) and Malachite Green (MG) dyes by visible light irradiation. The saturation magnetization value of the MF@CS composite is found to be 7.8 emu/g, which is less when compared to that of pristine Fe3O4 (55.7 emu/g) particles. The bandgap of the MF@CS composite is âˆ¼ 2.17eV, which exceeds the bandgap (Eg) of bare MoS2 of 1.80 eV. The maximum color removal of 96.3 % and 93.4 % for MB and MG dyestuffs is recognized in the exposure of the visible spectrum, respectively. At a starting dye dosage of 30 mg/L, 0.1 g/L of MF@CS, a pH level of 8-11, and 70 min of contact with direct light. The photocatalyst provides extremely good durability for a maximum of five phases. Hence, the MF@CS matrix is a viable and appropriate substance for the efficient treatment of effluents containing dye molecules.

Assessing the ecological impact of pesticides/herbicides on algal communities: A comprehensive review.

The escalating use of pesticides in agriculture for enhanced crop productivity threatens aquatic ecosystems, jeopardizing environmental integrity and human well-being. Pesticides infiltrate water bodies through runoff, chemical spills, and leachate, adversely affecting algae, vital primary producers in marine ecosystems. The repercussions cascade through higher trophic levels, underscoring the need for a comprehensive understanding of the interplay between pesticides, algae, and the broader ecosystem. Algae, susceptible to pesticides via spillage, runoff, and drift, experience disruptions in community structure and function, with certain species metabolizing and bioaccumulating these contaminants. The toxicological mechanisms vary based on the specific pesticide and algal species involved, particularly evident in herbicides' interference with photosynthetic activity in algae. Despite advancements, gaps persist in comprehending the precise toxic effects and mechanisms affecting algae and non-target species. This review consolidates information on the exposure and toxicity of diverse pesticides and herbicides to aquatic algae, elucidating underlying mechanisms. An emphasis is placed on the complex interactions between pesticides/herbicides, nutrient content, and their toxic effects on algae and microbial species. The variability in the harmful impact of a single pesticide across different algae species underscores the necessity for further research. A holistic approach considering these interactions is imperative to enhance predictions of pesticide effects in marine ecosystems. Continued research in this realm is crucial for a nuanced understanding of the repercussions of pesticides and herbicides on aquatic ecosystems, mainly algae.

Transesterification of Jatropha curcas oil to biodiesel using highly porous sulfonated biochar catalyst: Optimization and characterization dataset.

The study involves a collection of data from the published article titled "Active sites engineered biomass-carbon as a catalyst for biodiesel production: Process optimization using RSM and life cycle assessment "Energy Conversion Management" journal. Here, the activated biochar was functionalized using 4-diazoniobenzenesulfonate to obtain sulfonic acid functionalized activated biochar. The catalyst was comprehensively characterized using XRD, FTIR, TGA, NH3-TPD, SEM-EDS, TEM, BET, and XPS analysis. Further, the obtained catalyst was applied for the transesterification of Jatropha curcas oil (JCO) to produce biodiesel. An experimental matrix was conducted using the RSM-CCD approach and the resulting data were analyzed using multiple regressions to fit a quadratic equation, where the maximum biodiesel yield achieved was 97.1 ± 0.4%, under specific reaction conditions: a reaction time of 50.3 min, a molar ratio of 22.9:1, a reaction temperature of 96.2 °C, and a catalyst loading of 7.7 wt.%. The obtained product biodiesel was analyzed using NMR and GC-MS analyzed and is reported in the above-mentioned article.

Recent Advances in Direct Regioselective C-H Chlorination at Aromatic and Aliphatic Positions.

Direct installation of key functionalities in a molecule through C-H bond activation is one of the thrust areas as well as challenging task in organic synthesis. Particularly, introduction of chlorine in a molecule imparts additional benefits for further functionalizations as well as improves the electronic behaviour such as lipophilicity and polarity towards drug development process. The chlorinated molecules have also been established as efficient biologically relevant scaffolds. Current manuscript has been focused on the direct installation of the chlorine atom at various aromatic and aliphatic positions to produce functional molecules. The key highlight of the manuscript belongs to the site selectivity (regioselectivity) for the installation of chlorine functionality. Manuscript describes the advanced methods developed for the direct C-H chlorination reactions and further simplified for the chlorination reactions at various positions including aromatic (o-, m-, and p-), benzylic, heteroaromatic, and aliphatic positions. Directing groups (DGs) and the coordination with the catalyst is the key for the enhancement of regioselectivities during direct C-H chlorination reactions.

Supercritical CO2 mediated construction of aluminium waste recovered γ-Al2O3 impregnated Dracaena trifasciata biomass-derived carbon composite: A robust electrocatalyst for mutagenic pollutant detection.

Inspired by the waste-to-wealth concept, we have recovered the gamma phase aluminium oxide nanoparticles (γ-Al2O3 NPs) from waste aluminium (Al) foils and fabricated a composite with Dracaena trifasciata biomass-derived activated carbon matrix (DT-AC) using supercritical carbon-di-oxide (SC-CO2) pathway. The prepared samples are characterized altogether by various micro- and spectroscopic analyses. Based on the results, the recovered γ-Al2O3 NPs are well impregnated in the DT-AC surface by the action of the microbubble effect from the SC-CO2. The higher D-band and ID/IG value of 1.07 in the Al2O3/DT-AC nanocomposite indicate increased defects and the amorphous nature of the carbon materials. The effect of scan rate (ν) demonstrated greater linearity in ν1/2 vs peak current in the electrochemical detection study of the mutagenic pollutant 4-(methylamino) phenol hemi sulfate, showing a quasi-reversible electron transfer process undergoing diffusion-controlled kinetics. Furthermore, the limit of detection is determined to be 3.2 nM L-1 with an extensive linear range, spanning from 0.05 to 618.25 µM/L. The incredible sensitivity of 2.117 µA µM-1 cm-2, along with excellent selectivity, repeatability, and stability, is observed. Further, the respectable recovery percentage of 98.61 % in the environmental water sample is perceived. The observed outcomes suggest that the prepared Al2O3/DT-AC composite performs as an excellent electrocatalyst material, and the processing techniques used are thought to be sustainable in nature.

Dual stimuli-responsive poly(N-isopropylacrylamide)-b-poly(L-histidine) chimeric materials for the controlled delivery of doxorubicin into liver carcinoma.

A series of dual stimuli responsive synthetic polymer bioconjugate chimeric materials, poly(N-isopropylacrylamide)55-block-poly(L-histidine)n [p(NIPAM)55-b-p(His)n] (n=50, 75, 100, 125), have been synthesized by employing reversible addition-fragmentation chain transfer polymerization of NIPAM, followed by ring-opening polymerization of α-amino acid N-carboxyanhydrides. The dual stimuli responsive properties of the resulting biocompatiable and membrenolytic p(NIPAM)55-b-p(His)n polymers are investigated for their use as a stimuli responsive drug carrier for tumor targeting. Highly uniform self-assembled micelles (∼55 nm) fabricated by p(NIPAM)55-b-p(His)n polymers display sharp thermal and pH responses in aqueous media. An anticancer drug, doxorubicin (Dox), is effectively encapsulated in the micelles and the controlled Dox release is investigated in different temperature and pH conditions. Antitumor effect of the released Dox is also assessed using the HepG2 human hepatocellular carcinoma cell lines. Dox molecules released from the [p(NIPAM)55-b-p(His)n] micelles remain biologically active and have stimuli responsive capability to kill cancer cells. The self-assembling ability of these hybrid materials into uniform micelles and their efficiency to encapsulate Dox makes them a promising drug carrier to cancer cells. The new chimeric materials thus display tunable properties that can make them useful for a molecular switching device and controlled drug delivery applications needing responses to temperature and pH for the improvement of cancer chemotherapy.

A Z-scheme BiYO3/g-C3N4 heterojunction photocatalyst for the degradation of organic pollutants under visible light irradiation.

Photocatalysis is one of the fascinating fields for the wastewater treatment. In this regard, the present study deals with an effective visible light active BiYO3/g-C3N4 heterojunction nanocomposite photocatalyst with various ratios of BiYO3 and g-C3N4 (1:3, 1:1 and 3:1), synthesised by a wet chemical approach. The as-synthesised nanocomposite photocatalysts were investigated via different physicochemical approaches like Fourier transform infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electrons microscopy (TEM), UV-vis diffuse reflectance spectroscopy (DRS), photoluminescence (PL) and photoelectrochemical studies to characterise the crystal structure, morphology, optical absorption characteristics and photoelectrochemical properties. The photocatalytic degradation ability of the prepared photocatalytic samples was also analysed through the degradation of RhB in the presence of visible light irradiation. Of all the synthesised photocatalysts, the optimised CB-1 composite showed a significant photocatalytic efficiency (88.7%), with excellent stability and recyclability after three cycles. O2•- and •OH radicals were found to act a major role in the RhB degradation using optimised CB-1 composite, and it possessed ~ 1 times greater photocurrent intensity than the pristine g-C3N4 and BiYO3. In the present work, a direct Z-scheme heterojunction BiYO3/g-C3N4 with a considerably improved photocatalytic performance is reported.

Novel decorated aluminium(iii) phthalocyanine complex with the application of MWCNTs on electrodes: electrochemical non-enzymatic oxidation and reduction of glucose and hydrogen peroxide.

In this study, we performed the physicochemical and electrochemical characterization of a decorated macrocyclic aluminium(iii) phthalocyanine complex (AlTMQNCAPc). Subsequently, the AlTMQNCAPc@MWCNT/GC electrode was used for the electrochemical detection of glucose and hydrogen peroxide (H2O2) by cyclic voltammetry (CV), differential pulse voltammetry (DPV), and chronoamperometry (CA). Moreover, the limit of detection, linear range, and sensitivity for glucose and H2O2 were investigated (CV: 2.5 nM L-1 and 25 nM L-1, 50-500 µM, 0.052 and 0.072 µA µmol cm-2; DPV: 3.1 nM L-1 and 18 nM L-1, 50-500 µM, 0.062 and 0.066 µA µmol cm-2 and CA: 10 nM L-1 and 20 nM L-1, 50-500 µM, 0.098 and 0.07 µA µmol cm-2, respectively). In addition, the AlTMQNCAPc@MWCNT/GC electrode showed good selectivity for the detection of glucose and H2O2 in the presence of common interfering substances, such as AA, DA, UA, glycine, l-cysteine, nitrite, Pb(ii), Cd(ii), Cu(ii), Co(ii), Hg(ii), Zn(ii), and glucose. For the detection of glucose and H2O2, the kinetic parameters, including the electron transfer coefficient and catalytic reaction rate constant, were also established. Finally, for usage in practical applications, the modified electrode was employed to achieve the quantitative detection of glucose and H2O2 in human urine and commercial samples of 3% H2O2, respectively.

Achieving Order in Disorder: Stabilizing Red Light-Emitting α-Phase Formamidinium Lead Iodide.

While formamidinium lead iodide (FAPbI3) halide perovskite (HP) exhibits improved thermal stability and a wide band gap, its practical applicability is chained due to its room temperature phase transition from pure black (α-phase) to a non-perovskite yellow (δ-phase) when exposed to humidity. This phase transition is due to the fragile ionic bonding between the cationic and anionic parts of HPs during their formation. Herein, we report the synthesis of water-stable, red-light-emitting α-phase FAPbI3 nanocrystals (NCs) using five different amines to overcome these intrinsic phase instabilities. The structural, morphological, and electronic characterization were obtained using X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), and X-ray photoelectron spectroscopy (XPS), respectively. The photoluminescence (PL) emission and single-particle imaging bear the signature of dual emission in several amines, indicating a self-trapped excited state. Our simple strategy to stabilize the α-phase using various amine interfacial interactions could provide a better understanding and pave the way for a novel approach for the stabilization of perovskites for prolonged durations and their multifunctional applications.

Effective degradation of chloramphenicol in wastewater by activated peroxymonosulfate with Fe-rich porous biochar derived from petrochemical sludge.

Excess sludge produced from biological wastewater treatment plant in petroleum industry is a kind of hazardous solid waste. Converting the sludge into biochar catalysts may help to reduce its environmental risk, recover resources and increase economic efficiency. However, the role of the sludge biochar in persulfate activation remains unclear, limiting its application in removing organic pollutants from water body. In this study, metal-rich petrochemical sludge was used to produce activated sludge biochar (ASC) via a two-step method of pyrolytic carbonization (400 °C-800 °C) and subsequent KOH activation (abbreviated as ASC 400-800). The physio-chemical properties of ASC 400-800 were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) and Raman. The chloramphenicol (CAP) removal performances of ASC 400-800/peroxymonosulfate (PMS) systems were evaluated. Results showed that porous sludge biochar was successfully prepared by the two-step method. At 800 °C, the specific surface area of ASC reached the highest value of 202.92 m2 g-1. At 600-800 °C, Fe3O4, Fe0, and graphitized carbon were formed in ASC. Among ASC 400-800, ASC 800 exhibited the best CAP removal performance in ASC 800/PMS system by adsorption combined with catalytic degradation. The optimal conditions identified for 0.31 mM CAP removal were ASC 800 2.0 g L-1, PMS 6.2 mM, and pH 2.0. SO4•-, •OH, and 1O2 may contribute to CAP degradation. The degradation pathways of CAP were proposed based on the identified degradation intermediates. Overall, this study confirmed that porous biochar derived from petrochemical sludge was an effective adsorbent or PMS catalyst to remove organic pollutants from wastewater.

Comparative risk assessment studies estimating the hazard posed by long-term consumption of PPCPs in river water.

This study assesses the risk due to Emerging Contaminants (ECs), present in Indian rivers - Ganga (650 million inhabitants), Yamuna (57 million inhabitants), and Musi (7,500,000 inhabitants), 13 ECs in total, have been used for risk assessment studies. Their concentrations (e.g., Fluconazole: 236950 µg/l, Ciprofloxacin: 31000 µg/l, Caffeine: 21.57 µg/l, etc.) were higher than the threshold concentrations for safe consumption (e.g. Fluconazole allowable level is 3.8 µg/l, and Ciprofloxacin allowable level is 0.51 µg/l). Three different pathways of emerging contaminants (ECs) transfer (oral water ingestion, oral fish ingestion, and dermal water contact) have been considered and the study is carried out in 2 ways: (i) deterministic and (ii) probabilistic approaches (using Monte Carlo iterative methods with 10000 simulations) with the aid of a software - Risk (version 7.5). The risk value, quantified by Hazard Quotient (HQ) is higher than the allowable limit of 1 for several compounds in the three rivers like Fluconazole (HQ = 18276.713), Ciprofloxacin (HQ = 278.675), Voriconazole (HQ = 14.578), Cetirizine (HQ = 1006.917), Moxifloxacin (HQ = 8.076), Caffeine (HQ = 55.150), and Ibuprofen (HQ = 9.503). Results show that Fluconazole and Caffeine pose the maximum risk in the rivers via the "oral pathway" that allows maximum transfer of the ECs present in the river (93% and 82% contribution to total risk). The risk values vary from nearly 25 times to 19000 times the United States Environmental Protection Agency (USEPA) threshold limit of 1 (e.g., Caffeine Infant Risk = 25.990 and Fluconazole Adult Risk = 18276.713). The most susceptible age group, from this study, is "Adults" (19-70 years old), who stand the chance of experiencing the adverse health hazards associated with prolonged over-exposure to the ECs present in the river waters. Musi has the maximum concentration of pollutants and requires immediate remediation measures. Further, both methods indicate that nearly 60-70% of the population in all the three study areas are at risk of developing health hazards associated with over-exposure to ECs regularly, making the areas inhabitable.

Xylopentose production from crop residue employing xylanase enzyme.

To produce xylo-oligosaccharides (XOS) from the agriculture waste, which included, green coconut and vegetable cocktail. The two pretreatment - hydrogen peroxide-acetic acid (HP-AC) and sodium hypochlorite-sodium hydroxide (SH-SH) - were used for this study. The optimal conditions for the pretreatment were 80 °C, 4.0 % NaClO, and 2 h, followed by 0.08 % NaOH, 55 °C, and 1 h. Further enzymatic hydrolysis of green coconut (GC) and vegetable cocktail (VC) were performed and found in case of GC, the best outcomes were observed. Different types of XOS were obtained from the treated biomass whereas a single type of XOS xylo-pentose was obtained in high quantity (96.44 % and 93.09 % from CG and VC respectively) with the production of other XOS < 2 %. This study presents a reasonably secure and economical method for turning secondary crop residue into XOS and fermentable sugars.

Construction of direct FeMoO4/g-C3N4-2D/2D Z-scheme heterojunction with enhanced photocatalytic treatment of textile wastewater to eliminate the toxic effect in marine environment.

A novel FeMoO4/g-C3N4-2D/2D Z-scheme heterojunction photocatalyst was prepared via wet chemical method. The observed structural morphology of FeMoO4/g-C3N4 reveals the 2D-iron molybdate (FeMoO4) nanoplates compiled with the 2D-graphitic carbon nitride (g-C3N4) nanosheets like structure. The photocatalytic activity of the g-C3N4, FeMoO4, and FeMoO4/g-C3N4 composites were studied via the degradation of Rhodamine B (RhB) as targeted textile dye under visible light irradiation (VLI). The optimal FeMoO4/g-C3N4 (1:3 ratio of g-C3N4 and FeMoO4) composite show an enhanced degradation performance with rate constant value of 0.02226 min-1 and good stability even after three cycles. Thus, the h+ and O2•－are the key radicals in the degradation of RhB under VLI. It is proposed that the FeMoO4/g-C3N4 Z-scheme heterojunction effectively enhances the transfer and separation ability of e-/h+ pairs, by the way increasing the photocatalytic efficiency towards the RhB degradation. Thus, the newly constructed Z-scheme FeMoO4/g-C3N4 heterojunction photocatalyst is a promising material for the remediation of wastewater relevant to elimination of toxic effect in marine environment.

One-step synthesis of rod-on-plate like 1D/2D-NiMoO4/BiOI nanocomposite for an efficient visible light driven photocatalyst for pollutant degradation.

Visible light active 1D/2D-NiMoO4/BiOI nanocomposite photocatalyst has been constructed by single step solvothermal method. Various compositions of NiMoO4/BiOI nanocomposites are prepared by loading different amounts of nickel molybdate (NiMoO4) (1, 2, 3 wt%) to the bismuth oxy iodide (BiOI) and investigated by XRD, FTIR, SEM, EDAX, TEM, UV-vis DRS, and PL analysis. Among the as-prepared photocatalysts, 1 wt% NiMoO4 incorporated BiOI (NMBI-1) showed superior photocatalytic activity with a rate constant of 0.0442 min-1 for methylene blue degradation. While the bandgap values of pure BiOI and NiMoO4 are 1.94 and 2.43 eV, respectively, the optimized NMBI-1 exhibited a lower bandgap energy of 1.64 eV, and showed about 2 and 3.7 times higher photodegradation ability than the pure NiMoO4 and BiOI, respectively, towards MB removal under visible light. The NMBI-1 nanocomposite photocatalyst is stable even after four cycles, indicating an excellent photostability and recyclability. Charge carriers on the interface of NiMoO4 and BiOI easily transferred via the newly formed heterojunction, thereby increasing the photocatalytic performance. Photochemically formed h+ and.OH are found to be the major species in the MB removal under visible light illumination. Therefore, the 1D/2D-NiMoO4/BiOI nanocomposite photocatalyst materials may be considered for the wastewater remediation processes.

Correction: green synthesis of silver nanoparticles using plant extracts and their antimicrobial activities: a review of recent literature.

[This corrects the article DOI: 10.1039/D0RA09941D.].

One-pot synthesis of bismuth yttrium tungstate nanosheet decorated 3D-BiOBr nanoflower heterostructure with enhanced visible light photocatalytic activity.

A visible light driven BiOBr/BixY1-xWO6 nanocomposite photocatalyst of various compositions are prepared by the addition of different amounts of KBr (0.5, 1.0, 1.5, 2.0 mmol) in BixY1-xWO6 by a one-pot hydrothermal method. Furthermore, the photocatalytic properties of the as-prepared materials are analyzed by the decomposition of methylene blue under visible light illumination. In particular, the BiOBr/BixY1-xWO6 nanocomposite prepared by taking 1.5 mmol of KBr present a superior photocatalytic ability (78.3%) with the rate constant value 0.016 min-1, a low bandgap (Eg = 2.51 eV) as well as photoluminescence emission intensity than other photocatalysts prepared in this study. The radical scavenging studies revealed that OH and h+ performed an imperative role in the decomposition of methylene blue. Furthermore, the optimized photocatalyst is stable even after four cycles, which exposes the excellent photostability and reusability properties of the photocatalyst. In addition, a plausible mechanism of decomposition of methylene blue under visible light irradiation is also proposed.

A new 5-bromoindolehydrazone anchored diiodosalicylaldehyde derivative as efficient fluoro and chromophore for selective and sensitive detection of tryptamine and F- ions: Applications in live cell imaging.

A novel indole hydrazone tagged moiety, 2-((5-bromo-1H-indol-2-yl) methylene) hydrazono) methyl)-4, 6-diiodophenol (BHDL) has been developed for the selective and sensitive detection of biogenic tryptamine and F- ions. The binding dexterity of probe BHDL towards F-/tryptamine (TryptA) has been investigated by UV-visible/fluorescence spectroscopy. In the presence of TryptA, probe exhibits strong enhancement in the emission band at 433 nm and the band at 555 nm underwent a blue shift accompanied by a decrease in intensity by the inhibition of Excited State Intramolecular Proton Transfer (ESIPT) on BHDL. Excitingly, complexation with F- ions as well triggers an enhancement in a fluorescence band at 430 nm with the concomitant disappearance of the emission band at 555 nm due to the inhibition of ESIPT and deprotonation process initiated by the hydrogen bonding complex formation. Further, Density Functional Theoretical (DFT) calculations have been performed to support the mechanism functioned on the probe BHDL in the presence of TryptA/F-.

Recent advances in multifunctional nanomaterials for photothermal-enhanced Fenton-based chemodynamic tumor therapy.

Photothermal (PT)-enhanced Fenton-based chemodynamic therapy (CDT) has attracted a significant amount of research attention over the last five years as a highly effective, safe, and tumor-specific nanomedicine-based therapy. CDT is a new emerging nanocatalyst-based therapeutic strategy for the in situ treatment of tumors via the Fenton reaction or Fenton-like reaction, which has got fast progress in recent years because of its high specificity and activation by endogenous substances. A variety of multifunctional nanomaterials such as metal-, metal oxide-, and metal-sulfide-based nanocatalysts have been designed and constructed to trigger the in situ Fenton or Fenton-like reaction within the tumor microenvironment (TME) to generate highly cytotoxic hydroxyl radicals (•OH), which is highly efficient for the killing of tumor cells. However, research is still required to enhance the curative outcomes and minimize its side effects. Specifically, the therapeutic efficiency of certain CDTs is still hindered by the TME, including low levels of endogenous hydrogen peroxide (H2O2), overexpression of reduced glutathione (GSH), and low catalytic efficacy of Fenton or Fenton-like reactions (pH 5.6-6.8), which makes it difficult to completely cure cancer using monotherapy. For this reason, photothermal therapy (PTT) has been utilized in combination with CDT to enhance therapeutic efficacy. More interestingly, tumor heating during PTT not only causes damage to the tumor cells but can also accelerate the generation of •OH via the Fenton and Fenton-like reactions, thus enhancing the CDT efficacy, providing more effective cancer treatment when compared with monotherapy. Currently, synergistic PT-enhanced CDT using multifunctional nanomaterials with both PT and chemodynamic properties has made enormous progress in cancer theranostics. However, there has been no comprehensive review on this subject published to date. In this review, we first summarize the recent progress in PT-enhanced Fenton-based CDT for cancer treatment. We then discuss the potential and challenges in the future development of PT-enhanced Fenton-based nanocatalytic tumor therapy for clinical application.