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Exposure to disinfectants, cleansers, and bleaching chemicals irritates the eyes, respiratory systems, and skin, triggering asthma and allergic rhinitis symptoms. Bleach, as the major constituent of cleansers, when used improperly or mixed with other indoor cleaning agents, produces harmful halogenated volatile organic compounds. This manuscript assesses the influence of excessive exposure to disinfectants, including bleaching agents, when used against infectious conditions related to SARS-COVID-19 and its management. The use and impact of different bleaching agents in cleansing and their associated problems have been analyzed and presented in this review. This analysis focuses on the conventional and post-pandemic approach towards bleaches. Usage of bleaching agents increased by a staggering 20.4% and 16.4% from January to March 2020 compared to the same period in 2018 and 2019. Mounting use of bleaching agents during the COVID-19 pandemic resulted in negative health effects like asthma, eye irritation, and skin allergies. An approximately 42% rise in poisoning cases, including a few deaths, has been associated with exposure to harmful chemicals involving bleaches during the recent pandemic. Bleaching agents are the primary sources of hazardous indoor pollutants; therefore, despite their importance in disinfection, their utility must be substantiated based on legal guidelines, disposal, and remedial measures. Thus, conducting future occupational exposure assessment studies for bleach hazard management is crucial. [ABSTRACT FROM AUTHOR]

Industrial starch oxidations are commonly carried out using sodium hypochlorite (NaOCl). Electrification of this process via continuous generation of NaOCl from sodium chloride (NaCl) in situ has the potential to substantially lower the environmental impact thereof, as brine waste streams are reduced, while occupational health and safety risks associated with the use of NaOCl, such as during transport, handling, and storage, can also be minimized. In the present study, the influence of continuous electrochemical generation of NaOCl from NaCl on the quality of the starch oxidation process is evaluated based on measurements of oxidized starch carboxylate contents (DSCO2H), molecular weights (Mws), and pasting characteristics in comparison to those of commercially available reference oxidized starches produced by oxidation with NaOCl in batch suspension processes. Recycling of the NaCl solution and how this affects the quality of the oxidized starch products is also investigated. By successfully preparing oxidized granular starches almost identical to the reference starches, the results show that it is feasible to electrify the oxidation process and that the original NaCl chloride solution can be recycled at least four times for in situ electrochemical generation of NaOCl. [ABSTRACT FROM AUTHOR]

Excess hypochlorite (ClO−) is harmful to living organisms and can cause various oxidative diseases in the human body. Owing to the toxicity of ClO−, the development of efficient fluorescence sensors to track ClO− is necessary. In this work, we report a novel thiourea‐based fluorescent turn‐on sensor 1‐(9‐ethyl‐9H‐carbazol‐3‐yl)‐3‐(naphthalen‐1‐yl)thiourea (ECNT) for recognizing ClO−. ECNT can detect ClO− with high selectivity, relatively low interference with other analytes, and a significantly fast response time (<1 s) through a desulfurization reaction. The detection limit of ECNT for ClO− is calculated as 5.59 μM. Of note, ECNT is a chemosensor that reacts the fastest with ClO− among the reported thiourea‐based fluorescence turn‐on sensors for detecting ClO−. The response mechanism of ECNT to ClO− is demonstrated through 1H NMR titration, ESI mass, and density functional theory calculations. [ABSTRACT FROM AUTHOR]

Measurement of ammonia level is very important in environment. Therefore, in this study, we have tried to introduce a modified, accurate, fast, accessible and inexpensive method for measuring ammonia level. Herein, Berthelot method was modified and optimised based on experimental design. In order to find important factors and corresponding optimal conditions, factorial design and response surface methodology were employed. The result showed that hypochlorite and salicylate are the significant factors in the method. The presence of ammonia in the solutions was detected by examining the colour changes of the sample solution to green. A linear range of 1.0–30.0 mg L−1 with detection limit of 0.4 mg L−1 was obtained. Different real samples were analysed for ammonia successfully. [ABSTRACT FROM AUTHOR]

The evaporation rate of disinfestants when sprayed on production surfaces is expected to vary under different weather conditions, but it is unknown how that affects efficacy. This study was an initial investigation into how the evaporation rates of water and six commercial disinfestants vary under eight weather condition categories. Additionally, an empirical model was developed on the evaporation rate of water in response to air temperature, relative humidity, solar radiation, vapor pressure deficit, and wind speed under the same eight weather condition categories. Isopropyl alcohol lost more weight due to evaporation over 4 h (P < 0.0001) than all other disinfestant solutions, and no differences (P = 0.05) existed between the other five disinfestant solutions and water. Isopropyl alcohol had a mean percentage weight loss of 71% under hot and sunny conditions, 43% under cool and cloudy conditions, and 6% under indoor laboratory conditions. Water, hypochlorite, quaternary ammonium, and peroxy disinfestant solutions evaporated at a similar rate over 4 h, with an approximate mean percentage weight loss of 17% under hot and sunny conditions, 6% under cool and cloudy conditions, and 1% under indoor laboratory conditions. The regression model that best explained the influence of weather on evaporation included the variables solar radiation, temperature, and wind speed (P < 0.0001, R2 = 0.5603). This information will be used further to model the evaporative rate of disinfestants under the same range of weather conditions when applied to multiple types of substrate materials that represent common horticultural plant production surfaces. [Figure: see text] The author(s) have dedicated the work to the public domain under the Creative Commons CC0 “No Rights Reserved” license by waiving all of his or her rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law, 2024.

Luminescent Ag nanoclusters (Ag NCs) are a promising probe material for sensing and bioimaging applications. However, the intrinsic obstacle of poor water stability and photostability greatly restrict their practical application in biological systems. Herein, we report the intracellular hypochlorite (ClO−) detection with amphiphilic copolymer-modified luminescent Ag NCs with good biocompatibility and photostability. The Ag NCs were synthesized by using chemically inert hydrophobic ligands and then modified with an amphiphilic (1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(poly(ethylene glycol))-2000]) (DSPE-PEG-2000) and sodium dodecyl sulfonate (SDS) for phase transfer. It was found that the approach of the removal of organic solvents during the phase transfer has remarkable influences on the properties of the Ag NCs, including their size, luminescence property, and aqueous stability. Furthermore, the silver core of Ag NCs could be oxidatively damaged by ClO−, thereby causing photoluminescence (PL) quenching. The ClO−-induced PL quenching was specific over the other common reactive oxygen species (ROS) as well as some common interferences. Finally, they have been successfully applied as a fluorescent nanoprobe for detecting exogenous and endogenous ClO− in living cells. [ABSTRACT FROM AUTHOR]

Hypochlorite (ClO-) and viscosity both affect the physiological state of mitochondria, and their abnormal levels are closely related to many common diseases. Therefore, it is vitally important to develop mitochondria-targeting fluorescent probes for the dual sensing of ClO- and viscosity. Herein, we have explored a new fluorescent probe, XTAP-Bn, which responds sensitively to ClO- and viscosity with off-on fluorescence changes at 558 and 765 nm, respectively. Because the emission wavelength gap is more than 200 nm, XTAP-Bn can effectively eliminate the signal crosstalk during the simultaneous detection of ClO- and viscosity. In addition, XTAP-Bn has several advantages, including high selectivity, rapid response, good water solubility, low cytotoxicity, and excellent mitochondrial-targeting ability. More importantly, probe XTAP-Bn is successfully employed to monitor the dynamic change in ClO- and viscosity levels in the mitochondria of living cells and zebrafish. This study not only provides a reliable tool for identifying mitochondrial dysfunction but also offers a potential approach for the early diagnosis of mitochondrial-related diseases. [ABSTRACT FROM AUTHOR]

Oxidative stress is a trigger for many diseases and occurs with the unstable hypochlorite (ClO−), known as one of the reactive oxygen species (ROS) in organisms. Then, HOCI is acknowledged as an oxidizing species that eliminates a variety of environmental pollutants. Hence, the development of novel methodologies for the selective and precise identification of HOCl/ ClO− is considered to be of utmost importance. In this study, the design, characterization, and applications of a fluorene-based fluorescent probe (FHBP) dependent on the ESIPT mechanism with a "turn-on" response for the sensitive/selective determination of ClO− against other competing samples were reported. The experimental results indicated that the detection limit for ClO−could be quantitatively determined by the probe to be 8.2 × 10−7 M. The binding constant of the probe FHBP with ClO− was computed as 9.75 × 103 M−1. In addition, the response time of FHBP was appointed to be 30 s, indicating a rapid reaction with ClO−. It has also been demonstrated that this probe can be successfully used for the detection of ClO− on filter papers, TLC sheets, cotton swabs, and real samples. [ABSTRACT FROM AUTHOR]

A mild and catalyst‐free protocol to obtain several 2‐chloromethylpyrrolidines by the use of a commercial solution of sodium hypochlorite is here reported, without the need for a light source. The choice of the solvent revealed to be crucial in the success of the reaction. Mechanistic studies, both experimental and computational, confirmed a radical mechanism, where the deprotonation step, followed by the oxidation of a N‐centered anion to the corresponding radical, allowed 2‐chloromethylpyrrolidines, by a very fast cyclization, to be obtained. Sodium hypochlorite plays the role of both the oxidant and the chlorine source. [ABSTRACT FROM AUTHOR]

Herein, we present a method for rapid ratiometric fluorescence detection of hypochlorite (ClO–) by carbon quantum dots (CDs). Glutathione (GSH) was utilized as the starting material for the synthesis of CDs through a hydrothermal process. A maximum fluorescence intensity at an emission wavelength of 435 nm was observed under an excitation wavelength of 335 nm. The inner filter effect (IFE) of curcumin (CCM) on CDs could be utilized to reduce the fluorescence intensity of CDs at 435 nm, while an emission peak emerged at 540 nm. ClO– could rapidly oxidize CCM due to its oxidizing properties, which weakened the IFE, leading to a decrease in the fluorescence intensity of CCM at 540 nm, while the fluorescence intensity of CDs at 435 nm is restored. In addition, CDs exhibited excellent selectivity and sensitivity in the fluorescence detection of ClO–, and a substantial sensitivity in the detection of ClO– was established within a concentration range of 1–1500 μM with a limit of detection of 36.54 nM. The spiked recovery tests of tap water, swimming pool water, and milk samples showed the feasibility of using CDs for the ratiometric fluorescence detection of ClO– in real samples. [ABSTRACT FROM AUTHOR]

Development of effective methods for analyzing hypochlorite is of great significance due to the crucial role of hypochlorite in live organisms, as an endogenously produced reactive oxygen species (ROS) in the human immune system. In this paper, a novel fluorescent probe based on 6-methylthiocoumarinyl formate was designed and synthesized in one step for detection of hypochlorite in MeCN/PBS (8:2, v/v, pH 7.4) medium. The probe showed high specificity for hypochlorite over other competitive ROS analytes, extreme large Stokes shift of 265 nm, rapid response to hypochlorite within 20 s, low detection limit of 1.57 μM, and a wide applicable range of pH 3–10. The sensing mechanism was demonstrated to be based on oxidation of methyl phenyl sulfide to sulfoxide by hypochlorite. The probe may have extensive application for selective and convenient detection of hypochlorite due to its multiple advantages. [ABSTRACT FROM AUTHOR]

Silver telluride represents one of the most important refractory silver mineral phases and requires the development of alternative processing routes. This work presents a detailed analysis of the effect of sodium and calcium hypochlorite species, HNO3, HCl, H2SO4 and pH on the kinetics and efficiency of silver telluride dissolution. The understanding of the reaction mechanism was complemented with the use of thermodynamic diagrams and characterization of the solid residues by the X-ray diffraction and SEM-EDS techniques. The results revealed that the presence of Ca(ClO)2 and H2SO4 promotes the secondary and massive precipitation of calcium sulfate. A comparison of the oxidative systems containing Ca(ClO)2 and NaClO showed that the solutions containing NaClO are more efficient and selective. The decrease in pH favors the tellurium dissolution due to an increase in the in-situ concentration of chlorine oxidizing species; the silver is transformed into silver chloride solid species on the surface of unreacted silver telluride. Thermodynamic and experimental studies revealed that silver chloride layer and the continuous consumption of hypochlorous acid promote the passivation of the system. The characterization of the solid residues evidenced that the type of acid contained in the systems modifies the morphology of the silver chloride layer. Finally, the surface characterization showed that passivation due to the formation of compact layer of silver chloride can be modified using a hypochlorite system containing nitric acid; this is due to a synergistic effect of nitrate and hypochlorite species on the kinetics of silver telluride dissolution. This effect is also discussed from a mechanistic viewpoint. Silver telluride is oxidized in different hypochlorite acid systems. Passivating compact layer of AgCl are obtained in H2SO4 and HCl. The HClO-HNO3 system accelerates the silver telluride dissolution. The presence of HNO3 promotes the formation of porous AgCl. 86% of Te is dissolved from silver telluride at pH 1 [ABSTRACT FROM AUTHOR]

This study presents an environmentally sustainable method for minimizing sludge production in the textile effluent sector through the combined application of electrokinetic (EK) and electrooxidation (EO) processes. AAS and XRF analyses reveal that utilizing acidic electrolytes in the EK method successfully eliminates heavy metals (Cu, Mn, Zn, and Cr) from sludge, demonstrating superior efficiency compared to alkaline conditions. In addition, the total removal efficiency of COD contents was calculated following the order of EK-3 (60%), EK-1 (51%) and EK-2 (34%). Notably, EK-3, leveraging pH gradient fluctuations induced by anolyte in the catholyte reservoir, outperforms other EK systems in removing COD from sludge. The EK process is complemented by the EO process, leading to further degradation of dye and other organic components through the electrochemical generation of hypochlorite (940 ppm). At an alkaline pH of 10.0, the color and COD removal were effectively achieved at 98 and 70% in EO treatment, compared to other mediums. In addition, GC–MS identified N-derivative residues at the end of the EO. This study demonstrates an integrated approach that effectively eliminates heavy metals and COD from textile sludge, combining EK with EO techniques. [ABSTRACT FROM AUTHOR]

Merocyanine 540 dye (MC 540) has been demonstrated as a 'turn-off' fluorescent probe to detect hypochlorite ions (ClO−) in an aqueous medium. MC 540 was separately investigated by fluorescence and absorption spectroscopy in the presence of various analytes, including cations and anions. It was revealed that the fluorescence intensity of MC 540 was effectively quenched with only ClO− ions without being affected by the other twenty-five analytes. This was also observed with the naked eye, and the color of MC 540 changed from pink to colorless in the presence of only ClO− ions. Moreover, fluorescence interference experiments were performed for ClO−. MC 540 was found to detect ClO− independently of other analytes. The interaction ratio between MC 540 and ClO− was determined as 4:1, and the binding constant (Ka) was calculated as 28.38 M−4 for MC 540. The detection limit (LOD) of ClO− was determined to be 6.83 nM. The presented method was reliably applied to drinking, natural spring, and tap water samples. Thus, it has been proven that the MC 540 can be used as a sensitive, selective, color-changeable, and easy-to-apply 'turn-off' fluorescence sensor to detect ClO− in a specific concentration range. [ABSTRACT FROM AUTHOR]

Hypochlorous acid and its hypochlorite are important reactive oxygen species in the body, and are involved in various physiological processes related to immunity; their rapid detection is of great significance. Here, we synthesized a fluorescent probe (TPAS) by condensation of 4‐(diphenylamino)benzaldehyde, carbohydrazide, and salicylaldehyde, which can be used for the detection of ClO− in water and sensing of acidic gas in its solid state. The probe showed strong selective recognition of ClO− in acetonitrile and good tolerance to interference ions. There were good linear responses between the intensity of absorbance and fluorescence and the amount of ClO−. The TPAS solid and its paper strips can emit red fluorescence when exposed to volatile acidic vapours. After being treated with NH3, the red fluorescence can be restored to yellow. The response process of TPAS to ClO− and acid gases was characterized using nuclear magnetic resonance, electrospray ionisation mass spectrometry, transmission electron microscopy, and density functional theory calculations. Furthermore, it can be utilized in analyzing ClO− in commercially available bleaching products; the detection results were basically compatible with the labelled values. In addition, the probe is biocompatible and can be applied for imaging ClO− in zebrafish. [ABSTRACT FROM AUTHOR]

Hypochlorite (ClO−) is an important metabolite that participates a series of intracellular signal communications, which is closely related with the generation and development of various diseases. Herein, we design and prepare reduced iodine-doped carbon dots (I-CDs) that are highly sensitive to ClO−. The proposed I-CDs show bright green fluorescence (FL), which can be efficiently quenched upon treatment with ClO− because of the destroy of I-CDs structure caused by oxidation of iodine by ClO−. This sensing platform displays a good linear response range of 1 − 60 μM with a low detection limit of 95.1 nM. Importantly, monitoring ClO− level in living cells is further realized, demonstrating the capability of this strategy to determine the content of intracellular ClO−. This work provides a promising tool for visual sensing ClO−, which is of great significance for early diagnosis of ClO− related diseases.

Using electrolytic zero-valent iron-activated sodium hypochlorite (EZVI-NaClO) to pretreat sludge, the capillary suction time (CST) was utilized to evaluate sludge dewaterability. Ammonia nitrogen (NH4-N), dissolved phosphorus, and total phosphorus in the supernatant were used to analyze sludge disintegration. This approach aimed to evaluate the effectiveness of the pretreatment process and its impact on the sludge composition. The migration and transformation of extracellular polymeric substances (EPS), including dissolved EPS (S-EPS), loosely boundEPS, and tightly bound-EPS (TB-EPS), were analyzed by detecting protein and polysaccharide concentrations and three-dimensional fluorescence excitation-emission spectroscopy (3D-EEM). The sludge particle properties, including sludge viscosity and particle size, were also analyzed. The results suggested that the optimal pH value, NaClO dosage, current, and reaction time were 2, 100 mg/gDS (dry sludge), 0.2A, and 30 min, respectively, with a CST reduction of 43%. Protein and polysaccharide contents in TB-EPS were significantly reduced in the EZVI-NaClO group. Conversely, protein and polysaccharides contents in S-EPS increased, suggesting that EZVI-NaClO treatment could disrupt the EPS. Besides, the viscosity of the treated sludge decreased from 195.4 to 54.9 mPa·S, indicating that sludge fluidity became better. ZEVI-NaClO could enhance sludge dewaterability by destructing protein and polysaccharide structure and improving sludge hydrophobicity. HIGHLIGHTS Electrolytic zero-valent iron-activated sodium hypochlorite (EZVI-NaClO)-modified extracellular polymeric substance (EPS) extracted from WAS.; EZVI-NaClO can reduce O = C-NH- that affects protein strength and stiffness.; EZVI-NaClO enhances the flocculation and hydrophobicity of EPS.;

The generation and presence of excessive hypochlorous acid derivative ionic form (ClO−) could cause various diseases, such as arteriosclerosis, DNA damage, and cardiovascular illness. It is a critical need to develop a highly sensitive sensor for reliable detection of ClO− in cells and water-soluble systems. In this work, a hydroxyl group has been introduced into the compound 2-amino-3-(((E)-4-(2-(2-(2-hydroxyethoxy)ethyl)-1,3-dioxo-2,3-dihydro-1H-benzo[de]isoquinolin-6-yl)benzylidene)amino)maleonitrile (NDC) to increase its solubility in water, at the same time, the hydrazone unit was designed as a specific recognition group for the "off–on" fluorescence probe of ClO−. The probe NDC presents high selectivity, sensitivity, anti-interference, and low detection limit (67 nM) for ClO−. The recognition mechanism that ClO− breaks the C=N bond and forms the fluorescent compound 4-(2-(2-(2-hydroxyethoxy)ethyl)-1,3-dioxo-2,3-dihydro-1H-benzo[de]isoquinolin-6-yl)benzaldehyde (ND-3) has been confirmed by time-of-flight mass spectrometry. The probe NDC presents a good performance in the actual test of water samples and can be designed as the test papers for the quick and convenient detection of ClO− range from 0 to 1 μM. Moreover, the practical application was demonstrated by the successful imaging of endogenous and exogenous ClO− in HeLa cells. Our fluorescent biomass-based platform opens vast possibilities for repeatability, sensitivity, and selectivity detection of ClO− in cells and water-soluble systems. Graphical abstract This is a visual representation of the abstract. [ABSTRACT FROM AUTHOR]

Objectives: The study aimed to evaluate the potential for the dissolution of organic tissue in areas of simulated complexity and cleaning of root canal walls of the new iVac® endodontic irrigation system. Material and methods: Thirty mandibular premolars were evaluated by scanning electron microscopy before and after biomechanical preparation. Then, they were distributed according to the final irrigation protocol into groups with conventional irrigation, ultrasonic agitation with metallic insert (UA), and iVac® system, and new photomicrographs were obtained. For tissue dissolution analysis, glass capillaries filled with catgut were attached to the cervical and apical thirds of twenty-one prototyped upper incisors. They were weighed before and after the previously mentioned irrigation protocols. The data were statistically compared with a significance level of 5%. Results: The final irrigation provided greater cleaning of the root canal walls in the cervical, middle, and apical thirds of the root canals (P < 0.05), with no statistically significant difference between UA and iVac®, regardless of the analyzed thirds. Both ultrasonic irrigation protocols dissolved a significantly greater volume than the conventional irrigation protocol (P < 0.05), with no difference between the two protocols (P < 0.05). Conclusions: The iVac® system showed root canal wall cleaning and tissue dissolution similar to UA with a metallic insert, and both were superior to conventional irrigation. Clinical relevance: The new irrigation system iVac is more effective than conventional irrigation and has similar root canal wall cleaning and tissue dissolution to UA. [ABSTRACT FROM AUTHOR]

Merocyanine 540 (MC540)- Manganese oxide (MnO2) system-based fluorescence sensor is reported as an anion sensor in aqueous solution. MnO2 was synthesized in the presence of Potassium permanganate (KMnO4) and Cetyltrimethylammonium bromide (CTAB) using 3-(N-morpholino) propane sulfonic acid (MOPS) buffer. The formation of MnO2 was first confirmed by a color change and characterized using Xray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Ultraviolet-Visible (UV-Vis). absorption spectroscopy techniques. Next, the interaction of MC540 with MnO2 in aqueous solution was investigated at various conditions by UV-Vis. absorption and fluorescence spectroscopy. The sensing ability of the MC540-MnO2 was tested to detect hypochlorite (ClO-) ion as a "Turn-off" fluorescent sensor. The MC540-MnO2 revealed to be high selectivity and sensitivity to detect hypochlorite (ClO-) ion without being affected by the other thirteen anions. The detection limits for ClO- were evaluated in two different concentration ranges and calculated to be 0.14 µM at 0.33-4.46 µM and 0.38 µM at 5.06-14.30 µM, respectively. [ABSTRACT FROM AUTHOR]

Hypochlorous acid (HClO/ClO−) is one of the important reactive oxygen species (ROS). It acts as a second signaling molecule within and between cells and is an indispensable active molecule in living organisms to regulate physiological and pathological processes. In this article, two fluorescent probes (PTF and PTA) for highly selective fluorescent recognition of ClO− were successfully synthesized based on the ICT mechanism by condensing phenothiazines with two hydrazides via the hydrazide structure (). PTF can identify different concentrations of ClO− in two steps. Due to its ClO− two site recognition, the probe exhibited good selectivity (specific recognition of ClO− over a wide concentration range), a fast time response (rapid recognition in seconds), a sufficiently low detection limit (3.6 and 11.0 nM), and large Stokes shifts (180 and 145 nm). Furthermore, the recognition of ClO− by contrasting probes with different substituents exhibited different fluorescence changes of ratiometric type and turn‐off. PTF successfully achieves the detection of exogenous and endogenous ClO− in aqueous solution and living cells. [ABSTRACT FROM AUTHOR]

Hypochlorite (ClO−), as a kind of essential reactive oxygen species, plays a crucial role in vitro and in vivo. Here, a ratiometric fluorescent probe (TPAM) was designed and constructed for sensing ClO− based on substituted triphenylamine and malononitrile, which exhibited obvious colour transfer from orange to colourless under daylight accompanied by noticeable fluorescence change from red to green in response to ClO−. TPAM could effectively monitor ClO− with the merits of fast response, excellent selectivity, high sensitivity and a low detection limit of 0.1014 μM. 1H NMR, mass spectra and theoretical calculations proved that ClO− caused the oxidation of the carbon–carbon double bond in TPAM, resulting in compound 1 and marked changes in colour and fluorescence. In addition, TPAM was utilized for imaging ClO− in living cells successfully with good photostability and biocompatibility. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Hypochlorite (ClO–) is an important reactive oxygen species produced by the immune system to fight off invading pathogens, but its over‐expression can interfere with normal physiological process and induce serious diseases. Although a variety of molecular probes have been reported for detecting ClO–, the development of advanced fluorescent tools with faster response and higher sensitivity to precisely monitor ClO– remains a challenge. In this work, two Hantzsch ester (a derivative of 1,4‐dihydropyridine) derived fluorescent probes MeDHP‐BCl and MeDHP‐PhBCl were constructed based on asymmetric BODIPY‐matrix. These probes exhibit significant fluorescence turn‐on in the ultra‐sensitive (detection limit < 1 nmol/L) and ultra‐fast response (≤ 5 s) to ClO–. The reaction has been determined to be a highly selective N‐chlorination of Hantzsch ester which cannot be activated by various common bioactive species, including nitric oxide (NO) that could oxidize Hantzsch ester under aerobic physiological conditions in most reports. MeDHP‐PhBCl possessed a relatively longer fluorescence emission wavelength and higher quantum yield after activation, while more notably, MeDHP‐BCl displayed lower cytotoxicity and more remarkable fluorescence increment in the response to ClO–, enabling selective and precise visualization of endogenous ClO– over‐expression in living RAW264.7 cells. [ABSTRACT FROM AUTHOR]

Objectives This study aims to assess the feasibility of simultaneously producing hydrogen and hypochlorous acid using a 2-compartment PEM water electrolysis cell with an installed membrane electrode assembly (MEA). Methods External power was applied to the PEM water electrolysis device through a potentiostat to induce the electrolysis reaction and to confirm the production of hydrogen and hypochlorite simultaneously. Linear Sweep Voltammetry (LSV) experiments were conducted, thereby determined the minimum voltage required for the electrolysis. Constant current experiments were performed by applying a fixed current of 1 A for 1 hour, measuring voltage changes every second to evaluate the stability and efficiency of hydrogen production. The hydrogen production rate was measured using a mass flow meter, while the hypochlorite production was determined using a portable free chlorine photometer. Results and Discussion In this study, the minimum voltage required for hydrogen generation in a PEM water electrolysis cell was investigated using LSV with Deionized (DI) water. The results showed that the current increased from around 1.4 V, indicating an approximate voltage efficiency of 82%. NaCl was introduced to the anode in the PEM electrolysis cell to induce electrochemical reactions. When the anolyte was NaCl, the voltage was observed to increase by 0.77 V compared to using DI water. Optimization experiments were conducted to investigate the influence of electrolyte concentration and flow rate on hypochlorite and hydrogen production. As the electrolyte concentration increased, the hypochlorite generation also increased, with a maximum of 104±0.50 mg/L observed with NaCl 10 g/L. Additionally, when the flow rate was reduced, the hypochlorite production increased, and at a reduced flow rate of 5 mL/min compared to 20 mL/min, hypochlorite generation increased by 127.3%. However, the hydrogen production showed no significant variation with NaCl concentration or flow rate. Conclusion This study explores a novel approach using PEM water electrolysis technology to simultaneously produce hydrogen and chlorinated disinfectants. The research employed a PEM electrolysis cell with the MEA to generate both chlorine-based compounds and hydrogen. By varying the concentration and flow rate of the anolyte, the production efficiencies of hypochlorite were compared. This system showed that PEM electrolysis can be a promising alternative for disinfection and energy production in terms of environmental protection and cost-effectiveness.

Luminescent Ag nanoclusters (Ag NCs) are a promising probe material for sensing and bioimaging applications. However, the intrinsic obstacle of poor water stability and photostability greatly restrict their practical application in biological systems. Herein, we report the intracellular hypochlorite (ClO−) detection with amphiphilic copolymer-modified luminescent Ag NCs with good biocompatibility and photostability. The Ag NCs were synthesized by using chemically inert hydrophobic ligands and then modified with an amphiphilic (1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(poly(ethylene glycol))-2000]) (DSPE-PEG-2000) and sodium dodecyl sulfonate (SDS) for phase transfer. It was found that the approach of the removal of organic solvents during the phase transfer has remarkable influences on the properties of the Ag NCs, including their size, luminescence property, and aqueous stability. Furthermore, the silver core of Ag NCs could be oxidatively damaged by ClO−, thereby causing photoluminescence (PL) quenching. The ClO−-induced PL quenching was specific over the other common reactive oxygen species (ROS) as well as some common interferences. Finally, they have been successfully applied as a fluorescent nanoprobe for detecting exogenous and endogenous ClO− in living cells.

Flexible silver substrates were made by in situ reduction of silver nanoparticles in bacterial cellulose membranes using the unique advantage of dopamine. Subsequently, we modified the substrate with 4-mercaptophenol (4-MP), a molecule capable of specifically recognizing ClO–, and its corresponding SERS signal changes with the concentration of hypochlorite, thus allowing the quantitative detection of ClO– content. The method showed a negative linear correlation (R2 = 0.9567) with the SERS intensity at 1077 cm−1 over the concentration range 0.5–100 µM, and the detection limit was 0.15 µM. The RSD of the SERS intensity at 1077 cm−1 under five batches was 4.2%, which proved the good reproducibility of P-BCM-Ag NP-MP. Finally, the P-BCM-Ag NPs were used for the detection of hypochlorite in cell contents, artificial urine, and clinical serum samples, utilizing spike experiments in all three environments. The recoveries were in the range 90–110% indicating the accuracy of the method for the detection of hypochlorite and validating the promising application of this assay for practical detection in intricate biological samples. [ABSTRACT FROM AUTHOR]

Microbial biofilm is one of the most serious problems facing poultry farms all over the world and especially in Egypt. Salmonella, E. coli and S. aureus were the highest implicated bacteria in biofilm formation in poultry farms. Consequently, 440 samples were collected from 8- broiler and 8-layer farms at El- Sharkia Province, Egypt, during the period from (July 2021 till August 2022). The objective of the study was to evaluate biofilm development capacity of the tested bacterial species by the microtiter plate (MTP) assay. Also, the efficacy of five disinfectants commonly used in poultry farms (Sodium hypochlorite, hydrogen peroxide, Virkon S, glutaraldehyde and copper sulphate) with different concentrations (1, 2 and 5%) and different contact times (10, 60 and 120 m) on reducing the biofilms produced by S. Enteritidis, E. coli O78 and S. aureus was estimated. Results showed that out of 440 collected samples, 17 (3.8%), 200(45.5%) and 66 (15%) strains were identified as Salmonella, E. coli and S. aureus, respectively. 88.2%, 92% and 87.8% of the isolates of Salmonella, E. coli and S. aureus were biofilm producers. The most effective disinfectant was sodium hypochlorite which eliminated the biofilms of S. Enteritidis and E. coli O78 when used at concentration 5% for 120 m while 5% for 60 m against S. aureus biofilm. Additionally, hydrogen peroxide showed great efficiency and complete removal of biofilm of S. Enteritidis when used at concentration 2% for 120m and 5%f or 120 m against S. aureus biofilm, meanwhile removed 91% of E. coli O78 biofilm when used at concentration of 5% for 120 m. However, Copper Sulphate was insufficient disinfectant to be used against the biofilms. It can be concluded that the anti-biofilm efficiency of the disinfectants increases with the increase concentration and contact time with biofilms especially when using oxidizing disinfectants (hypochlorite and peroxides). [ABSTRACT FROM AUTHOR]

Objective: The serologic levels of both nitric oxide (NO) and hypochlorite (ClO-) were assessed in this study for Iraqi acute leukemic patients infected with Gram negative bacteria (GNB). Alongside, the phylogenetic analysis for both blaSHV and blaTEM genes of GNB was performed. Methods: The clinical samples were recovered from acute leukemic patients at hematology center in Baghdad from January 2021 to December 2021. The identification of bacterial isolates and susceptibility test were performed using Vitek 2 Compact System. Serum levels of NO and ClO- were assayed by Enzyme Linked Immunosorbent assay and colorimetric method, respectively. Gene screening was done utilizing polymerase chain reaction. DNA sequencing, GenBank accession numbers submission, and phylogenetic analysis were also conducted. Results: From 260 patients with acute leukemia, 485 clinical samples were collected from different sites. Of this total, 70 (15%) isolates of GNB were obtained, distributing as Klebsiella pneumoniae 23 (33%), Escherichia coli 21 (30%), Pseudomonas aeruginosa 18 (26%), and Acinetobacter baumannii 8 (11%). These isolates were mainly collected from urine 39 (55.71%), followed by blood 23 (32.85%), and the least from swabs 8 (11.42%). The infections of GNB were higher among acute myeloblastic leukemia (AML) patients 40 (57.14%) than these with acute lymphoblastic leukemia (ALL) 30 (42.85%). The levels of NO were higher among groups of patients than control groups. Additionally, ClO- levels were observed to be slightly increased in patients above these of controls. Most isolates of K. pneumoniae and E. coli showed high resistance rates for penicillins (ampicillin and ticarcillin), cephalosporins (ceftazidime, cefotaxime, ceftriaxone, and cefepime), followed by gentamicin and ciprofloxacin. Cefoxitin, aztreonam, imipenem and meropenem were nearly more effective against GNB isolates. On the other hand, about half isolates P. aeruginosa and all A. baumannii were resistant to the tested antibiotics. Extended Spectrum ß-Lactamases (ESBLs) were released in 49 (70%) of the tested isolates of GNB. The multidrug resistant (MDR) pattern was noticed among 58 (82.85%) of GNB. Interestingly, ESBLs producing MDR isolates were determined in 34 (58.62%) of the studied GNB. Genotypic screening revealed that blaSHV and blaTEM genes were characterized in 20 (28.57%) and 32 (45.71%) of GNB isolates, respectively, while all GNB were negative for blaCTX-M. DNA sequencing of blaSHV amplicons revealed the occurrence of one point mutation (111T>A) in six isolates of K. pneumoniae with a missense effect (p.31Q>L) on the encoded protein. Forty-five GenBank accession numbers were recorded in NCBI to represent the studied variants of ESBLs. Phylogenetic analysis of both blaSHV and blaTEM displayed the possible epidemiologic routes of the tested GNB by detecting the origin host, source of collection, and geographic spread as compared with the reference sequences. Conclusion: High serum levels of both NO and ClO- indicated the potential role of these microbicidal agents to predict the serious infections of GNB in acute leukemia population. Phylogenetic analysis represented an important tool, possibly aiding in early control and prevention of pathogenic GNB. [ABSTRACT FROM AUTHOR]

The propagation of Gundelia tournefortii L. via seed faces certain problems due to the strongly lignified disseminule from secondary capitulum. Therefore, in this study, in first, the interaction of chemical and mechanical scarification (Control, sodium hypochlorite, H2O2, scalpel and sand paper for 10 min) with cold stratification (0, 1, 2, 3 weeks) or nitrogenous compounds(control, thiourea, nitrate, sodium nitroprusside) on seed dormancy breaking were investigated in two separate factorial experiments. Results showed that all scarification methods significantly increased emergence percentage and growth of seedlings and the interaction of scarification methods with stratification or nitrogenous compounds on these attributes was significant. In the first experiment, the highest emergence percentage (75.6 %) and length of seedlings (22.4 cm) was gathered in treatment of seed scarification by scalpel + 3 weeks cold stratification. In the second experiment, the maximum emergence percentage (65.6 %) and length of root (10.2 cm) and shoot (8.1 cm), and minimum mean time of emergence (11.5 days) of seedlings, was obtained in treatment of seed scarification by scalpel and applying sodium nitroprussid (SNP). In third experiment, the impact of combined application of SNP and cold stratification was assessed on dormancy breaking of seeds scarified with scalpel. Results showed that the application of SNP reduced duration of cold stratification required for obtaining the best emergence indices and maximum dry weight of seedlings. These results indicate that Gundelia tournefortii seeds have physical and physiological dormancy and can achieve the highest percentage of emergence (85%) and the lowest average emergence time (8.5 days) by treatments of scarification with scalpel and then cold stratification or SNP treatment. [ABSTRACT FROM AUTHOR]

Removal of necrotic tissue is a vital step in the treatment of full-thickness burn wounds, with surgical debridement being the most effective method. Since minor burn wounds are typically treated on an outpatient basis where surgical capabilities can be limited there is a need for alternative treatment options. In this study we aim to evaluate the use of amino acid buffered hypochlorite (AABH) as a chemical enhancement for wound debridement in a porcine infected burn wound model. A total of 60 full-thickness burn wounds, 3 cm in diameter, were created on four pigs using a standardized burn device. The wounds were inoculated with 107 colony-forming units (CFU) of S. aureus. The experimental groups included wounds debrided with a plastic curette, wounds debrided after pretreatment with AABH, and control wounds wiped with gauze. Wounds were treated twice per week for three weeks. Debridement, healing, and infection parameters were evaluated over time. After one week, but not after two and three weeks, the curette and AABH groups had higher debrided weights compared to control (p < 0.05). Percentage of wound area adequately cleared from necrotic tissue was higher in the AABH-group compared to the curette-group and control, after one week. The earliest healing was measured in the AABH group after two weeks (5 % of wounds), which also had the most healed wounds after three weeks (55 %). In both the AABH and the curette groups, bacterial load had fallen below 105 CFU/g after two weeks. No CFU were detectable in the AABH group after three weeks. The AABH-group was also the easiest to debride. Our results indicate that AABH facilitates wound debridement and could be a helpful addition to an effective treatment modality for removal of necrotic tissue in full-thickness burns. • Successful debridement of burns improve healing and reduce infection. • Treatment with amino acid buffered hypochlorite facilitates debridement of burns. • A porcine infected burn model is suitable for translational studies of debridement. [ABSTRACT FROM AUTHOR]

Mitochondrial hypochlorite (ClO−) plays important and often contradictory roles in maintaining the redox balance of mitochondria. Abnormal ClO− levels can induce mitochondrial inactivation and further cause cell apoptosis. Herein, we have developed an anthracene carboxyimide-based fluorescent probe mito-ACS for imaging mitochondrial ClO− in living cells. This probe exhibits some distinctive features as excellent resistance to photobleaching, high selectivity and sensitivity, as well as good water solubility. Mito-ACS showed a noticeable fluorescence response toward ClO− with a fast response (within 6 s) and a low detection limit (23 nM). Moreover, the introduction of triphenylphosphonium makes the probe soluble in water and selectively localizes to mitochondria. Furthermore, mito-ACS was successfully applied to image mitochondria ClO− in living cells with low toxicity. Remarkably. the less used fluorophore anthracene carboxyimide exhibiting excellent photostability and desirable optical properties provides a promising application prospect in biological systems. [ABSTRACT FROM AUTHOR]

The authors describe an unusual case of chemical sinusitis and orbital cellulitis secondary to a sodium hypochlorite accident in a patient who had just undergone root canal treatment. The patient presented with acute, progressive symptoms of unilateral maxillary sinusitis, facial cellulitis and orbital cellulitis which began hours after root canal treatment on the ipsilateral side. He was admitted to hospital under the care of the Otorhinolaryngology team and reviewed regularly by the Ophthalmologists. He underwent Endoscopic Sinus Surgery during his hospital stay. The intraoperative findings revealed necrotic sinus mucosa and slough within the involved maxillary sinus, which were suggestive of chemical burn injury induced by the highly alkaline sodium hypochlorite solution used during root canal treatment. He was treated postoperatively with regular nasal toilet, culture-directed antibiotics and topical ocular pressure-lowering eyedrops. He displayed a slow recovery with eventually no orbital sequelae, but experienced persistent cheek numbness three months post-injury. Severe chemical sinusitis with orbital cellulitis secondary to sodium hypochlorite accident is a rare complication of root canal treatment, with potentially severe consequences. It can present with symptoms similar to complicated acute bacterial sinusitis. Otorhinolaryngologists and dental surgeons should maintain a high index of suspicion when managing a patient post-root canal treatment with symptoms of unilateral sinusitis, facial cellulitis, orbital cellulitis and even airway compromise. This would allow prompt intervention before sight or life-threatening complications set in.

The efficient utilization of natural lignin, which is the main by-product of the cellulose industry, is crucial for enhancing its economic value, alleviating the environmental burden, and improving ecological security. By taking advantage of the large sp2 hybrid domain of lignin and introducing amino functional groups, new lignin-derived carbon dots (SPN-CDs) with red fluorescence were successfully synthesized. Compared with green and blue fluorescent materials, red SPN-CDs have desirable anti-interference properties of short-wave background and exhibit superior luminescence stability. The SPN-CDs obtained exhibited sensitive and distinctive visible color with fluorescence-dual responses toward hypochlorite. Considering this feature, a portable, low-cost, and sensitive fluorescence sensing paper with a low limit of detection of 0.249 µmol·L−1 was fabricated using the SPN-CDs for hypochlorite detection. Furthermore, a new type of visible-light and fluorescence dual-channel information encryption platform was constructed. Low-concentration hypochlorite can be employed as an accessible and efficient information encryption/decryption stimulus, as well as an information "eaaser", facilitating a safe and diversified transmission and convenient decryption of information. This work opens new avenues for high-value-added applications of lignin-based fluorescent materials. [ABSTRACT FROM AUTHOR]

This work aims to evaluate the quality of drinking water in the Disi aquifer in Jordan. Several water quality parameters are included in the mathematical equation to evaluate the average water quality and establish the suitability of water for drinking purposes. Water sampling zones from three wells were used to calculate the water quality indices (WQI). The water samples were analyzed for several physicochemical parameters, including pH, turbidity, total dissolved solids, Na+, Ca2+, Mg2+, Na+, K+, HCO3−, SO42−, Cl−, NO3−, total hardness, electrical conductivity (EC) and other elements (Fe2+, Zn2+, Mn2+, Cd2+, As2−, Pb4+ and Cu2+), in the groundwater wells. Biological parameters, such as faecal coliform, were also tested. The Weighted Arithmetic WQI indicated that most of the wells were of good to excellent quality. These determined indices support decision making and are beneficial to monitoring the groundwater quality in the Disi aquifer. The relative weight is specific to each parameter and ranges from 1 to 5; it establishes the importance of the water quality parameters for domestic purposes. The WQI analysis rates the water quality between 75 to 65 from good to medium. The water quality of the Disi aquifer for potable drinking water was compared with the guidelines of the World Health Organization (2011) and the Jordan Drinking Standard (JS286); the results indicated that water in the Disi aquifer was of high quality and was fit for drinking. [ABSTRACT FROM AUTHOR]

Optical sensor arrays are widely used in obtaining fingerprints of samples, allowing for solutions of recognition and identification problems. An approach to extending the functionality of the sensor arrays is using a kinetic factor by conducting indicator reactions that proceed at measurable rates. In this study, we propose a method for the discrimination of proteins based on their oxidation by sodium hypochlorite with the formation of the products, which, in turn, feature oxidation properties. As reducing agents to visualize these products, carbocyanine dyes IR-783 and Cy5.5-COOH are added to the reaction mixture at pH 5.3, and different spectral characteristics are registered every several minutes (absorbance in the visible region and fluorescence under excitation by UV (254 and 365 nm) and red light). The intensities of the photographic images of the 96-well plate are processed by principal component analysis (PCA) and linear discriminant analysis (LDA). Six model proteins (bovine and human serum albumins, γ-globulin, lysozyme, pepsin, and proteinase K) and 10 rennet samples (mixtures of chymosin and pepsin from different manufacturers) are recognized by the proposed method. The method is rapid and simple and uses only commercially available reagents. [ABSTRACT FROM AUTHOR]

A novel dual-response fluorescence probe (XBT-CN) was developed by using a fluorescence priming strategy for quantitative monitoring and visualization of hydrazine (N2H4) and hypochlorite (ClO−). With the addition of N2H4/ClO−, the cleavage reaction of C=C bond initiated by N2H4/ClO− was transformed into corresponding hydrazone and aldehyde derivatives, inducing the probe XBT-CN appeared a fluorescence "off-on" response, which was verified by DFT calculation. HRMS spectra were also conducted to confirm the sensitive mechanism of XBT-CN to N2H4 and ClO−. The probe XBT-CN had an obvious fluorescence response to N2H4 and ClO−, which caused a significant color change in unprotected eyes. In addition, the detection limits of XBT-CN for N2H4 and ClO− were 27 nM and 34 nM, respectively. Interference tests showed that other competitive analytes could hardly interfere with the detection of N2H4 and ClO− in a complex environment. In order to realize the point-of-care detection of N2H4 and ClO−, an XBT-CN@hydrogel test kit combined with a portable smartphone was developed. Furthermore, the portable test kit has been applied to the detection of N2H4 and ClO− in a real-world environment and food samples, and a series of good results have been achieved. Attractively, we demonstrated that XBT-CN@hydrogel was successfully applied as an encryption ink in the field of information security. Finally, the probe can also be used to monitor and distinguish N2H4 and ClO− in living cells, exhibiting excellent biocompatibility and low cytotoxicity. [ABSTRACT FROM AUTHOR]

Green emission carbon dots (CDs) electrochemically prepared from 2,6-pyridinedicarboxylic acid and o-phenyl-enediamine were applied separately for the quantitation of hypochlorite and carbendazim. The characteristic and optical properties of the CDs were studied through fluorescence, UV--vis absorption, X-ray photoelectron spectroscopy, and transmission electron microscopy. The synthesized CDs were mainly 0.8--2.2 nm in size, with an average size of 1.5 nm. The CDs exhibited green luminescence centered at 520 nm when excited by 420 nm light. The green emission of the CDs is quenched after the addition of hypochlorite, mainly through the redox reaction between hypochlorite and hydroxyl groups on the CDs surface. Furthermore, the hypochlorite-induced fluorescence quenched can be prevented in the presence of carbendazim. The sensing approaches exhibit good linear ranges of 1--50 µM and 0.05--5 µM for hypochlorite and carbendazim, respectively, with low detection limits of 0.096 and 0.005 µM, respectively. Practicalities of the luminescent probes were separately validated by the quantitation of the two analytes in real sample matrix with recoveries ranging from 96.3 to 108.9% and the relative standard deviation values below 5.51%. Our results show the potential of the sensitive, selective, and simple CD probe for water and food quality control. [ABSTRACT FROM AUTHOR]

Chronic wound infection is highly associated with morbidity and endangers the patient's life. Therefore, wound care products must have a potent antimicrobial and biofilm-eradicating effect. In this work, the antimicrobial/antibiofilm activity of two low-concentrated chlorine-based and releasing solutions was investigated on a total of 78 strains of methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans, using the cohesive spectrum of in vitro settings, including microtiter plate models, biofilm-oriented antiseptic test, cellulose-based biofilm model, biofilm bioreactors and Bioflux model. The antiseptic containing polyhexamethylene biguanide was used in the character of usability control of performed tests. The results obtained by static biofilm models indicate that low-concentrated chlorine-based and releasing solutions display none to moderate antibiofilm activity, while data obtained by means of the Bioflux model, providing flow conditions, indicate the moderate antibiofilm activity of substances compared with the polyhexanide antiseptic. Considering in vitro data presented in this manuscript, the earlier reported favorable clinical results of low-concentrated hypochlorites should be considered rather an effect of their rinsing activity combined with low cytotoxicity but not the antimicrobial effect per se. For the treatment of heavily biofilm-infected wounds, polyhexanide should be considered the agent of choice because of its higher efficacy against pathogenic biofilms. [ABSTRACT FROM AUTHOR]

Herein, a miniaturized, three-electrode paper-based electrochemical sensing platform for selective and sensitive electroanalytical sensing of hypochlorite has been reported. A hybrid method for fabricating the electrochemical device on the paper-based substrate, using ink-jet printing with conductive carbon inks as counter and reference electrode, has been demonstrated. Further, a CuO@Graphite sheet was incorporated separately using adhesive double-sided tape on the paper-based substrate, which served as the working electrode. The prepared device was subjected to hypochlorite solution of 1 mM to explore the electrochemical behavior of chlorine. Cyclic voltammetry (CV) and square-wave voltammetry (SQWV) were leveraged in the potential window of − 0.7 V to 0 V for conducting the experiments, whereby a sharp reduction peak at a peak potential E0 = − 0.43 V vs Ag/AgCl was obtained. Further, the consequence of potential scan rate and the effect of concentration and interference from other chemicals were also analyzed. A linear concentration range of 90–10 nM and a detection limit of 13.15 nM (9.78 × 10–4 ppm) with standard deviation of 1.013 were obtained. The fabricated paper-based electrode system was also tested on real samples such as lake water and tap water and the results are presented. [ABSTRACT FROM AUTHOR]

Excessive levels of hypochlorite (ClO−) negatively affect environmental and biological systems. Thus, it is essential to develop sensors that can identify ClO− in various systems such as the environment and living organisms. In this study, we report the development and evaluation of a novel aggregation-induced emission (AIE) strategy-based colorimetric and ratiometric fluorescent chemosensor 2,2′-(((1E,1′E)-[2,2′-bithiophene]− 5,5′-diylbis(methanylylidene))bis(hydrazin-1-yl-2-ylidene))bis(N,N,N-trimethyl-2-oxoethan-1-aminium) chloride (BMH-2∙Cl) for detecting ClO−. BMH-2∙Cl enabled highly selective ClO− detection through a color change from yellow to colorless and a fluorescence color change from turquoise to blue in a perfect aqueous solution. BMH-2∙Cl exhibited low limits of detection (2.4 ×10−6 M for colorimetry and 2.9 ×10−7 M for ratiometric fluorescence) for detecting ClO− with a rapid response within 5 s. The detection mechanism for ClO− and an AIE property change of BMH-2∙Cl were demonstrated by 1H NMR titration, ESI-MS, variation of water fraction (fw) and theoretical calculations. In particular, we confirmed not only the practicality of BMH-2∙Cl by using test strips, but also demonstrated the potential for efficient ClO− detection in biological and environmental systems such as real water samples, living zebrafish and bean sprouts.

In recent years, various methods for detecting exogenous and endogenous hypochlorite have been studied, considering its essential role as a biomolecule. However, the existing technologies still pose obstacles such as their invasiveness, high costs, and complicated operation. In the current study, we developed a glow-type chemiluminescent probe, hypochlorite chemiluminescence probe (HCCL)-1, based on the scaffold of Schaap's 1,2-dioxetane luminophores. To better explore the physiological and pathological functions of hypochlorite, we modified the luminophore scaffold of HCCL-1 to develop several probes, including HCCL-2, HCCL-3, and HCCL-4, which amplify the response signal of hypochlorite. By comparing the luminescent intensities of the four probes using the IVIS® system, we determined that HCCL-2 with a limit of detection of 0.166 μM has enhanced sensitivity and selectivity for tracking hypochlorite both in vitro and in vivo.

Chronic wound infection is highly associated with morbidity and endangers the patient's life. Therefore, wound care products must have a potent antimicrobial and biofilm-eradicating effect. In this work, the antimicrobial/antibiofilm activity of two low-concentrated chlorine-based and releasing solutions was investigated on a total of 78 strains of methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans, using the cohesive spectrum of in vitro settings, including microtiter plate models, biofilm-oriented antiseptic test, cellulose-based biofilm model, biofilm bioreactors and Bioflux model. The antiseptic containing polyhexamethylene biguanide was used in the character of usability control of performed tests. The results obtained by static biofilm models indicate that low-concentrated chlorine-based and releasing solutions display none to moderate antibiofilm activity, while data obtained by means of the Bioflux model, providing flow conditions, indicate the moderate antibiofilm activity of substances compared with the polyhexanide antiseptic. Considering in vitro data presented in this manuscript, the earlier reported favorable clinical results of low-concentrated hypochlorites should be considered rather an effect of their rinsing activity combined with low cytotoxicity but not the antimicrobial effect per se. For the treatment of heavily biofilm-infected wounds, polyhexanide should be considered the agent of choice because of its higher efficacy against pathogenic biofilms.

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A new pyrene-based fluorescent probe (PM) for detection of hypochlorite was synthesized through the reaction of aldehyde with methylene and well characterized. PM presents highly selective fluorescence enhancement response toward OCl− over a variety of different analytes, including metal ions, anions and some compounds with redox properties via the unique reaction of Meldrum's acid with OCl−. The results of mass spectra, FTIR spectra and density functional theory calculation demonstrated that the fluorescence enhancement of PM is attributed to the inhibition of intramolecular charge transfer due to the protonation of O atoms on Meldrum's acid molecule after the oxidation reaction of OCl− on PM. The fluorescence intensity of PM at 517 nm in aqueous solution displayed a good linear relationship with the concentration of OCl− in a wide range with a low detection limit of 4.24 μM. Additionally, the viability of HepG-2 cell after being incubated in 15 μM PM solution for 24 h can reach 90%, indicating that PM has very low cytotoxicity. PM can recognize OCl− in living cells by the fluorescent confocal imaging. PM has the potential application in detection and recognition of OCl− in environmental systems and living organisms. [ABSTRACT FROM AUTHOR]

Sodium hypochlorite was widely used as a supplementary disinfectant in reclaimed water (RW) production during the COVID-19 epidemic. It is well known that the chlorination of RW results in a relatively high bacterial regrowth potential in pipeline systems. However, the algal growth and algal–bacterial interactions would be another concern in RW-replenished surface water with light irradiation. In this study, microcosmic experiments were used to explore the impact of hypochlorite on the algae–bacteria community, including the influence of hypochlorite on algal–bacterial regrowth, microbial community structure, and the specific bacteria that can survive chlorination. Results demonstrated that algal growth potential could be promoted after chlorination of the RW, and bacteria abundance increased along with an increase in algal density, which is probably related to DOM decomposition by chlorine oxidation. Additionally, the characteristics of the bacterial community were altered. It is more likely that phytospheric bacteria will survive chlorination. It was discovered that the secondary risks of chlorine disinfection include the growth of algae in addition to bacterial regeneration, which is an extension of the common perception. As a consequence, when chlorinated reclaimed water is used as a supplement for urban landscape ponds, particular attention should be paid to controlling bio-available organic matter induced by reactive chlorine, as well as the algal bloom, to decrease the risk of pathogen transmission. [ABSTRACT FROM AUTHOR]