Orange Red Dyes Research Articles

Enhanced sunlight-driven catalysis for hydrogen generation and dye remediation using synergistic p-Co3O4/n-TiO2 nanocomposites.

In this study, p-Co3O4/n-TiO2 nanocomposites were synthesized using different ratios of cobalt and titanium precursors through a hydrothermal method. These nanocomposites demonstrated notable potential in photocatalytic applications for hydrogen production and orange-red dye degradation under sunlight. Various techniques, including XRD, Raman spectroscopy, XPS, FESEM, TEM, and BET analysis, were used to comprehensively characterize their structural, morphological, and optical properties. The nanocomposites exhibited both cubic and tetragonal phases of Co3O4 and TiO2, and their combined effect resulted in a narrowed band gap. Additionally, the presence of Co3O4 induced surface plasmon resonance on the TiO2 surface, effectively impeding electron-hole recombination. The nanocomposites displayed an average particle size of ∼20 to 30 nm with substantial visible light absorption. High crystallinity and well-dispersed nanocomposites were confirmed by XRD and Raman, with BET surface areas ranging between 49 and 106 m2 g-1. Notably, the p-Co3O4/n-TiO2 nanocomposite showed superior photocatalytic activity, achieving a maximum hydrogen generation rate of 1120 μmol h-1 g-1 and an 83% degradation efficiency of the orange-red dye within 6 minutes under sunlight. This study emphasizes the enhanced performance of the p-Co3O4/n-TiO2 nanocomposite, indicating its potential in photocatalytic applications, conforming to a pseudo-first-order kinetics model.

Blackberry gel-assisted combustion modified MgO: Sm3+ nanoparticles for photocatalytic, battery, sensor and antibacterial applications

Green synthetic methods are currently preferred in industry over other physicochemical methods. Herein, we present a facile, environmentally friendly, non-toxic approach for the fabrication of MgO using jamun fruit extract. The phytochemicals present in the fruit extract, such as kaemferol, glucoside, anthocyanins, ellagic acid, myricetin, and isoquercetin, facilitate the bio-reduction of Mg(NO3)2. Pure and Sm3+ (1–7 mol %) doped MgO nanomaterials were synthesized using this bio-mediated synthetic method. The structural and morphological properties of the synthesized nanomaterials were studied using Powder X-ray diffraction (PXRD), Field Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive Spectroscopy (EDS), and Diffused Reflectance Spectroscopy (DRS) techniques. The effect of Sm3+ ions on the host matrix for the photo-catalytic oxidation of Fast Orange-Red (FOR) dye was investigated under UV light irradiation. MgO: Sm3+(3 mol %) exhibited superior (94 %) degradation of the dye compared to pristine and other doped catalysts, attributed to the maximum migration of charge carriers at the catalyst's surface. Additionally, the 3 mol % Sm3+ doped MgO electrode demonstrated a smaller charge transfer resistance, indicating superior capacitive properties compared to pristine and other doped electrodes. The synthesized materials also exhibited effective bacterial activity against pathogens. This research demonstrates the potential of the synthesized nanomaterials for environmental pollution purification, as well as their utility as electrode materials for supercapacitors, batteries, sensors, and antibacterial applications.

MgAl2O4:Ho3+ Nanophosphors: Electrochemical Sensor, Photoluminescence and Photocatalytic Applications

Ho3+-doped MgAl2O4 nanophosphors (1-11 mol%) was synthesised via solution combustion method using oxalyl dihydrazide (ODH) as fuel. The findings revealed a range of band gap energies (Eg) between 4.86 and 5.42 eV. It was confirmed that these values correspond extremely well with the experimental data using the DFT approach. The Ho3+ ions in the host undergo f-f transitions that are triggered at 406 nm and as a result, exhibit discrete photoluminescence emission peaks between 406 and 605 nm. Enhanced MgAl2O4 have CIE coordinates from orange-red to yellow region and 97% colour purity. Photocatalytic properties of nanophosphors under UV light led to the discovery that a rapid orange-red dye is activated at 493 nm. Removal of fast orange red (F-OR) dye using the new photocatalysts and MgAl2O4:Ho3+ nanophosphors has been demonstrated. The investigation showed that 89.02% of the dye lost its colour after being exposed to radiation for 120 min. The modified MgAl2O4:Ho3+ carbon paste electrode used in the cyclic voltametric (CV) technique for lead pollution detection. Based on their electrochemical performance, it is concluded that MgAl2O4:Ho3+ nanophosphors are a viable material for lead detecting electrodes.

Hydrothermally synthesized cobalt vanadate nanoparticles for photocatalytic degradation of Fast Orange Red dye and supercapacitor applications

Herein, Co2V2O7 and Co3V2O8 nanoparticles (NPs) were synthesized by changing only the precursor molar ratio using a simple hydrothermal approach. Numerous analytical approaches were used to characterise the synthesized NPs. The crystal structures of the NPs were found to be monoclinic (Co2V2O7) and orthorhombic (Co3V2O8) with an average crystallite size of 29 nm and 25 nm, respectively. Furthermore, the band gaps for Co2V2O7 and Co3V2O8 were calculated to be 1.8 eV and 2.1 eV, respectively. The supercapacitor properties of both the synthesized NPs were performed. After 1000 cycles, the specific capacitance values were determined to be 628 F·g−1 for Co2V2O7 nanoparticles and 415 F·g−1 for Co3V2O8, indicating an excellent retention rate of almost 90 % for both materials. Furthermore, stability measurements at a current density of 5 A·g−1 demonstrated that even after 3000 cycles, the capacitive retention remained stable at 90 %. The photocatalytic investigations for the degradation of Fast Orange Red dye using Co2V2O7 and Co3V2O8 was performed. Co2V2O7 showed a decolourization rate of 93.8 %, whereas Co3V2O8 had a decolourization rate of 88.95 % within 120 min of UV light irradiation. Overall, the research sheds light on the properties of Co2V2O7 and Co3V2O8 nanoparticles, making them viable candidates for practical energy and environmental applications. The obtained results also motivate the synthesis of comparable NPs with improved characteristics for real-world applications.

Isolation and Identification of Lawsonia Content from the Leaves of Henna (Lawsonia inermis)

Lawsone is an orange red dye mainly isolated from Lawsonia inermis plant leaves. L. inermis is commonly known as henna plant, Egyptian privet, or mignonette tree. In Pakistan, henna is known as mehndi. Paste from thick henna leaves has been used to dye hairs, fingernails, palms of hands, and eyebrows for more than 5000 years. The characteristic colour of henna is because of the natural dye lawsone present in it. In this study, lawsone was extracted from four samples of henna leaves collected from various parts of Pakistan. Moreover, the impact of the environment on the leaves was examined. Lawsone was extracted using diethyl ether, so that the maximum amount of lawsone could be isolated from the leaves. The maximum and minimum amount of lawsone isolated during this work was 1.01% and 0.745% of dry weight, respectively. Afterwards, IR and HPLC were used to identify the isolated reddish-brown substance known as lawsone which is useful in textile, cosmetics, and pharmaceutical sectors.

A selective and sensitive colorimetric method for semi-automated solid-phase extraction of atrazine in environmental water samples

A selective and sensitive procedure for the trace analysis of atrazine (ATZ) in surface water samples was developed using the semi-automated solid-phase extraction (SPE) coupled with a colorimetric method. In this work, we developed Konig’s reaction using p-anisidine as a new coupling agent to form a red-colored dye product having λmax 500 nm and tuned the reaction conditions to occur at 40 °C. The possible structure of the orange-red dye product was proposed based on HPLC-UV and UPLC-MS analyses. Under the optimized conditions, the method provided linearity range of 10–30 µg/L with a good coefficient of determination (R2 > 0.99) in different sample matrices. The limit of detection and limit of quantification were 2.49 and 7.54 µg/L, respectively. The method validity was evaluated by analyzing the ATZ spiked samples collected from paddy fields, fish farms, and natural canal waters with a recovery range of 104–119 %, and the results were in good agreement with those obtained using HPLC-UV. The developed method was able to reduce the requirement of high heating temperature for the conventional Konig’s reaction and was expected to be used for the practical analysis of ATZ at the ppb levels in natural water.

Almond gum assisted synthesis of Mg doped Fe2O3 NPs: Structural analysis, electrochemical sensing, and optical applications

• The prepared Mg doped Fe 2 O 3 NPs were well characterized by PXRD, SEM, FT-IR and UV–Visible spectral techniques. • Photocatalytic activity of Mg doped Fe 2 O 3 photocatalyst on fast orange red dye dye under UV irradiation was discussed. • Anti-inflammatory activity of prepared ZnO NPs was tested and ZnO-2 has high potent inhibitor of PLA 2 with MIC value of 41 µg/ml. • An electrochemical measurement and paracetamol chemical sensor activities were carried out for prepared Mg doped Fe 2 O 3 NPs. • The Mg doped Fe 2 O 3 NPs was prepared by combustion method using Almond gum green fuel. Mg-doped Fe 2 O 3 nanoparticles (M-FNPs) are successfully prepared first time by facile green-aided (almond gum) combustion route. The structural analysis of synthesized nanoparticles was well analyzed by Powder X-ray Diffraction (PXRD), Fourier Transform Infrared spectroscopy (FT-IR), Scanning Electron Microscope (SEM), Raman spectroscopy and UV-Visible spectral studies. PXRD showed a nanocrystalline nature and determined the average particle size to be 85 nm. The surface morphologies of the prepared nanocomposite was measured by SEM technique reveals the porous and spongy like structure. The photodegradation activity on 20 × 10 −6 of Fast Orange Red (FOR) organic model dye using M-FNPs (50 mg) under UV light irradiation was investigatedin detail. Electrochemical examination of the prepared material was conducted using graphite–M-FNP electrode paste in 0.1 M KCl solution, and its performance in redox reaction was determined to be very good via cyclic voltammetry and electrochemical impedance spectroscopy. Further, an extension to sensor studies revealed broad differences in redox positions for paracetamol sensors, at 0.64 V and 0.41 V, confirming highly chemical sensor activity in alkaline medium for 1∼5 mM concentrations.

Photocatalytic degradation of direct green & fast orange red dyes: Electrochemical sensor of lead using cupric oxide nanoparticles synthesized via sonochemical route

In this study, nanocrystalline cupric oxide was produced using a basic, low-cost sonochemical method (CuO). Through powder X-ray diffraction, the phase and nanocrystalline nature of CuO nanoparticles (NPs) were determined. The Kubelka-Monk function revealed that the band gap of CuO in diffuse reflectance spectra (DRS) is 1.75 ​eV. Ingenious photocatalysts for the removal of the dyes Direct green (DG) and Fast orange red (F-OR) have been demonstrated to work with CuO NPs. To examine the photocatalytic characteristics of NPs under UV light and sunlight irradiation, Direct Green (DG) and Fast Orange Red (F-OR) dyes were utilised as traditional dyes. Direct green dye was found to be excited at 624.1 and 623.8 ​nm in UV and sunlight, while Fast orange red dye is excited at 496.8 and 495.1 ​nm. Lead in 0.1 ​N HCl solution was detected using the cyclic voltammetry (CV) method with a modified carbon paste electrode (MCPE). According to electrochemical performance, CuO is an advantageous sensing electrode material for an element like lead.

Highly Efficient Candlelight Organic Light-Emitting Diode with a Very Low Color Temperature.

Low color temperature candlelight organic light-emitting diodes (LEDs) are human and environmentally friendly because of the absence of blue emission that might suppress at night the secretion of melatonin and damage retina upon long exposure. Herein, we demonstrated a lighting device incorporating a phenoxazine-based host material, 3,3-bis(phenoxazin-10-ylmethyl)oxetane (BPMO), with the use of orange-red and yellow phosphorescent dyes to mimic candlelight. The resultant BPMO-based simple structured candlelight organic LED device permitted a maximum exposure limit of 57,700 s, much longer than did a candle (2750 s) or an incandescent bulb (1100 s) at 100 lx. The resulting device showed a color temperature of 1690 K, which is significantly much lower than that of oil lamps (1800 K), candles (1900 K), or incandescent bulbs (2500 K). The device showed a melatonin suppression sensitivity of 1.33%, upon exposure for 1.5 h at night, which is 66% and 88% less than the candle and incandescent bulb, respectively. Its maximum power efficacy is 23.1 lm/W, current efficacy 22.4 cd/A, and external quantum efficiency 10.2%, all much higher than the CBP-based devices. These results encourage a scalable synthesis of novel host materials to design and manufacture high-efficiency candlelight organic LEDs.

Antimicrobial, Antioxidant, and Dye Degradation Properties of Biosynthesized Silver Nanoparticles From Artemisia Annua L.

The biosynthesis of metallic nanoparticles with plant extract is a promising alternative method to traditional chemical methods. Artemisia annua L is a well-known Chinese herb for its potent therapeutic anti-malarial activity and antitumor effects. Artemisinin, a sesquiterpene lactone derived from Artemisia annua L. Although artemisinin's anticancer effect has been extensively reported, the precise mechanisms underlying its cytotoxicity remain under intensive study. In the present work rapid and simple method for green synthesis of silver nanoparticles with the leaf extract of the therapeutic plant Artemisia annua L.was carried-out. The biologically synthesized silver nanoparticles were analyzed using spectroscopic methods like UV–visible spectroscopy. Fourier transforms infrared spectroscopy (FT-IR), Zeta potential, and particle size. The green Aa-AgNPs are characterized by spectral analysis by Nanodrop-UV-visible spectroscopy. The surface Plasmon resonance peak of silver nanoparticles in colloidal solution showed maximum absorption 441nm. FT-IR spectroscopy results indicate the O-H phenolic group's participation, C=C aromatic stretching, N-H secondary amide stretching, and C-H methylene group stretching. Dynamic light scattering measurements of Aa-AgNPs revealed that the particle size is between 5-20 nm. The zeta potential of the green synthesized Aa-AgNPs was found to be -26.1 mV. The high negative potential indicates long-term stability. The antioxidant activity of Aa-AgNPs was evaluated by DPPH assay. The results revealed that they have very good antioxidant activity, which can be useful as a potential free radical scavenger. The biosynthesized Aa-AgNPs of Artemisia annua exhibited good antimicrobial activity. The Aa-AgNPs showed excellent catalytic activity in the reduction of lemon yellow and orange-red food dyes. The Aa-AgNPs can also act as an effective seed germination agent. Hence it is concluded that the green Aa-AgNPs can be useful for various biomedical and industrial applications.

Effect of Synthetic Red Dye Orange Red and Natural Red Dye Alizarin on Biochemical and Hematological Parameters in Male Wistar Rats

Nowadays synthetic food dyes are mostly preferred than natural plant derived dyes due to low cost and intense coloration. In this study hematological and biochemical parameters were determined in male wistar rats after 30 days treatment with synthetic red dye orange red and natural plant derived red dye alizarin. 25 male wistar rats were divided into 5 groups with 5 animals per group. Group I rats were taken as control treated with normal rat diet and distilled water. Group II and III rats (experimental) were oral gavaged with 50 mg and 150 mg/kg body weight of alizarin dye. Group IV and V rats (experimental) were gavaged with 50 mg and 150 mg/kg body weight of orange red dye. Treatment of group V rats with 150 mg/kg body weight of orange red dye produce significant changes in RBC, Hb, Hct, MCH, serum aminotransferase enzymes and serum protein fraction. In comparison to this in group IV rats a significant change was observed only in Hb, serum aminotransferase enzymes and serum protein fraction when compared with control (group I) rats. However in group II and III alizarin treated rats no significant change was observed in different biochemical and hematological parameters relative to their respective control. In conclusion synthetic orange red dye proved to be more toxic than natural plant derived red dye alizarin.

Optical second harmonic generation and two-photon luminescence in organic microstructures

We studied optical and second order nonlinear optical effects in arrays of frustum-shaped microstructures composed of orange-red dye by self-assembling technique.

Column performance of carbon nanotube packed bed for methylene blue and orange red dye removal from waste water

Environmental issues have always been a major issue among human kind for the past decades. As the time passes by, the technology field has grown and has helped a lot in order to reduce these environmental issues. Industries such as metal plating facilities, mining operations and batteries production are a few examples that involves in the environmental issues. Carbon nanotube is proven to possess excellent adsorption capacity for the removal of methylene blue and orange red dyes. The effect of process parameters such as pH and contact time was investigated The results revealed that optimized conditions for the highest removal for methylene blue (MB) (97%) and orange red (94%) are at pH 10, CNTs dosage of 1 grams, and 15 minutes for each dyes removal respectively. The equilibrium adsorption data obtained was best fit to Freundlich model, while kinetic data can be characterized by the pseudo second-order rate kinetics.

An endophytic fungus, Gibberella moniliformis from Lawsonia inermis L. produces lawsone, an orange-red pigment.

Lawsone (2-hydroxy-1, 4-napthoquinone), also known as hennotannic acid, is an orange red dye used as a popular skin and hair colorant. The dye is produced in the leaves of Lawsonia inermis L, often referred to as the "henna" tree. In this study, we report the production of lawsone by an endophytic fungus, Gibberella moniliformis isolated from the leaf tissues of Lawsonia inermis. The fungus produced the orange-red dye in potato dextrose agar and broth, independent of the host tissue. Presence of lawsone was confirmed spectrometrically using HPLC and ESI-MS/MS analysis. The fragmentation pattern of lawsone was identical to both standard lawsone and that extracted from plant tissue. This is a first report of lawsone being produced by an endophytic fungus, independent of the host tissue. The study opens up interesting questions on the possible biosynthetic pathway through which lawsone is produced by the fungus.

Spectrophotometric Evaluation of Colour Stability of Nano Hybrid Composite Resin in Commonly Used Food Colourants in Asian Countries.

There is growing interest in colour stability of aesthetic restorations. So far few studies have been reported. This study was designed to investigate the effects of different common food colourants i.e., Turmeric and Carmoisine (orange red dye) consumed by patients in Asian countries on a recent nano hybrid composite resin. A total of sixty disk shaped specimens measuring 10 mm in diameter and 2 mm in thickness were prepared. The samples were divided into two groups {Z 100 (Dental restorative composite) Filtek Z 250 XT (Nano hybrid universal restorative)}. Baseline colour measurement of all specimens were made using reflectance spectrophotometer with CIE L*a*b* system. Specimens were immersed in artificial saliva and different experimental solutions containing food colourants (carmoisine solution and turmeric solution) for three hours per day at 37°C. Colour measurements were made after 15 days. Colour difference (ΔE*) was calculated. Mean values were compared by one-way analysis of variance (ANOVA). Multiple range test by Tukey Post-hoc test procedure was employed to identify the significant groups at 5% level. Z 100 showed minimum staining capacity when compared to Z 250 XT in both the colourant solutions. The nanohybrid composite resin containing TEGDMA showed significant colour change when compared to that of microhybrid composite resin as a result of staining in turmeric and carmoisine solution.

Determination of Dicofol in Various Environmental Samples by Spectrophotometric Method Using Chromogenic Reagent

A sensitive spectrophotometric method for determination of dicofol in subparts per million levels is described, which is based on Fujiwara reaction. Dicofol on alkaline hydrolysis gives chloroform, which reacts with pyridine to produce red color. The color is discharged by addition of glacial acetic acid. The glutaconic aldehyde formed reacts with 4-aminoacetanilide to gave an orange-red dye which is extractable in 3-methyl-1-butanol. The extracted dye shows absorption maximum at 525 nm. Beer's law is obeyed in the range of 0.025–0.25 μg mL−1. Important analytical parameters such as time, temperature, reagent concentration, acidity etc. have been optimized for complete color reaction. Sandell's sensitivity and molar absorptivity for the system were found to be 0.000343 μg cm−2 and 1.077 × 106 L mol−1cm−1, respectively. The proposed method is satisfactorily applied to microlevel determination of dicofol in various environmental samples.

A facile strategy for synthesis of nearly white light emitting mesoporous silica nanoparticles

A series of novel fluorescent mesoporous silica nanoparticles (MSNs) with a diameter of about 50nm was fabricated by introducing a blue-light emitting Zn complex of 2-(2-hydroxyphenyl)benzothiazole (BTZ) and an orange-red light dye (Rhodamine B). The bright nearly white emitting MSNs (RhB0.65–(BTZ)xZn@MSN) can be obtained by tuning the concentration and ratio of different fluorescent emitting centers (RhB and (BTZ)xZn). The sample of RhB0.65–(BTZ)xZn@MSN had a chromaticity coordinate of (0.33, 0.30) which is well within the white region of the chromaticity diagram. The obtained fluorescent MSNs still remained the good mesoporous structure and highly dispersibility in ethanol solution after functionalized with dyes. The prepared different fluorescent MSNs have a potential application feature in many field of biomedical drug delivery, cell labeling and optoelectronic devices.

Spectrophotometric analysis of trichloroethylene in various environmental and biological samples

A simple sensitive extractive spectrophotometric method for determination of trichloroethylene is proposed. Trichloroethylene is treated with pyridine to form glutaconic aldehyde by heterolytic cleavage of the pyridine ring. Glutaconic aldehyde is further coupled with 4-aminoacetanilide to form an orange–red dye which is extractable in 3-methyl-1-butanol. The extracted dye shows absorption maximum at 520 nm. The system obeys Beer’s law in the range of 0.05–0.8 μg mL−1. Important analytical parameters such as time, temperature, reagent concentration, acidity etc. have been optimized for complete colour reaction. Sandell’s sensitivity and molar absorptivity for the system were found to be 0.001 μg cm−2 and 1.2 × 105 L mol−1 cm−1, respectively. The proposed method is satisfactorily applied to micro-level determination of trichloroethylene in various environmental and biological samples.

Batch and Flow-Injection Spectrophotometric Determination of Thymol Using Procaine Hydrochloride as a New Chromogenic Reagent

New, simple and sensitive batch and Flow-injecton spectrophotometric methods for the determination of Thymol in pure form and in mouth wash preparations have been proposed in this study. These methods were based on a diazotization and coupling reaction between Thymol and diazotized procaine HCl in alkaline medium to form an intense orange-red water-soluble dye that is stable and has a maximum absorption at 474 nm. A graphs of absorbance versus concentration show that Beer’s law is obeyed over the concentration range of 0.4-4.8 and 4-80 µg.ml-1 of Thymol, with detection limits of 0.072 and 1.807 µg.ml-1 of Thymol for batch and FIA methods respectively. The FIA procedure sample throughput was 80 h-1. All different chemical and physical experimental parameters that affecting on the development and stability of the colored product were carefully studied and the proposed methods were successfully applied to the determination of Thymol in mouth wash preparations.

Batch and Flow-Injection Spectrophotometric Determination of Thymol Using Procaine Hydrochloride as a New Chromogenic Reagent

New, simple and sensitive batch and Flow-injecton spectrophotometric methods for the determination of Thymol in pure form and in mouth wash preparations have been proposed in this study. These methods were based on a diazotization and coupling reaction between Thymol and diazotized procaine HCl in alkaline medium to form an intense orange-red water-soluble dye that is stable and has a maximum absorption at 474 nm. A graphs of absorbance versus concentration show that Beer’s law is obeyed over the concentration range of 0.4-4.8 and 4-80 µg.ml-1 of Thymol, with detection limits of 0.072 and 1.807 µg.ml-1 of Thymol for batch and FIA methods respectively. The FIA procedure sample throughput was 80 h-1. All different chemical and physical experimental parameters that affecting on the development and stability of the colored product were carefully studied and the proposed methods were successfully applied to the determination of Thymol in mouth wash preparations.