Variations in the biochemical characteristics of Lavandula sublepidota Rech.f. in response to the foliar enrichment of green-synthesized copper nano complexes from extract of neem and jujube.

Copper (Cu) is an essential micronutrient in plant physiology and biochemistry. This article synthesized copper nano complexes (Cu-NCs) based on aqueous extracts of jujube and neem leaves. The effects of foliar application of Cu-jujube and Cu-neem Cu-NCs at concentrations of 0, 10, 25, and 50 mg L-1 on the bioactive compounds, antioxidant capacity, and essential oil of the Iranian native medicinal herb Lavandula sublepidota Rech. f. was investigated. The highest levels of flavonoids and polyphenols were observed in the plants treated with Cu-NCs at 25 mg L-1. However, no superiority was observed between the two types of Cu-NCs. Furthermore, 25 mg L-1 nCu-Z and nCu-N foliar application boosted essential oil yield (48 and 52%, respectively) over control. This suggests an ideal threshold beyond which toxicity was found. Similarly, the amount of commercially significant secondary metabolites increased at 25 mg L-1 CuNCs compared to 10 and 50 mg L-1 concentrations. The maximum antioxidant activity was found in extracts of lavender that had been treated with 25 mg L-1 CuNCs. When CuNCs were applied exogenously, the extracts' antibacterial activity (MIC µg mL-1) was substantially increased against the three pathogen strains. The results suggest that CuNCs demonstrate notably greater effectiveness, particularly at an ideal concentration of 25 mg L-1, in enhancing the production of essential oil and bioactive compounds in Lavandula sublepidota Rech. f. Therefore, these findings indicate the importance of the biosynthesis of NCs using plants and measuring the phytochemical changes of lavender plants.

Bioactive compounds of Punica granatum L. wastes by high performance liquid chromatography analysis.

The massive pomaces of Punica granatum L. exhibit a challenging losses exposure difficulty for the processing industries. The resent study was aimed to investigate the bioactive compounds of pomace extracts to introduce it to different industries such as pharmaceutical, food, medicinal, agricultural etcetera for optimum use. Four different extracts were prepared and the phenolic compounds were quantified using HPLC-DAD. Different amounts of phenolic compounds were detected in the samples including gallic acid, catechin, ellagic acid, rosmarinic acid, hesperidin, p-coumaric acid and chlorogenic acid. Gallic acid was major compound in all studied extracts of pomaces, with the maximum amount belonging to water extract (at 60 °C). The average amount of gallic acid detected in water extract (at 60 °C) of Punica granatum L. was 11.25 mg g-1 dry weight, while it was 3.24 3.02 and 1.09 mg g-1 dry weight for the extracts obtained by distilled water, methanol and methanol 80%, respectively.

A novel and simple naphthol azo dye chemosensor as a naked eye detection tool for highly selective, sensitive and accurate determination of thiourea in tap water, juices and fruit skins.

In the present study, a highly accurate and sensitive azo-dye-based colorimetric sensor based on Eriochrome Black T (EBT) was proposed to detect and determine thiourea (TU). TU is truly an important toxic and carcinogenic hazardous pollutant as approved by EPA and IARC. This chemosensor shows a distinct color change from blue to pink during interaction with TU in aqueous medium. So EBT is capable as an applied tool for naked eye detection of TU as its color change is easily observed without any means. The sensing mechanism was also investigated using UV-vis absorption and FT-IR spectra. The linear range and the detection limit of TU sensing were respectively 0.15-18.5 µmol/L and 0.02 µmol/L. In addition, the relative standard deviation (RSD) based on ten repetitions calculated for two different TU concentrations 4.4 and 9.0 µmol/L were 2.3 % and 1.8 %, respectively. Besides its useful application as a naked eye detection tool, the advantages of the developed method include simplicity, elimination of tedious separation and pre-concentration steps, executable in neutral aqueous media, low costs, high accuracy, linear response for wide range of concentrations, low detection limit, high sensitivity, compatibility, and excellent selectivity. The concentration of TU in tap water, fruit juices or fruit skin samples can be visually detected and determined easily using this method. The results showed that EBT is an ideal colorimetric chemosensor for TU, which has been reported for the first time.

A novel design of multiple ligands for ultrasensitive colorimetric chemosensor of glutathione in plasma sample.

In this study, we developed a novel colorimetric chemosensor for selective and sensitive recognition of Glutathione (GSH) using a simple binary mixture of commercially accessible and inexpensive metal receptors with names, Bromo Pyrogallol Red (BPR) and Xylenol Orange (XO). This procedure is based on the synergistic coordination of BPR and XO with cerium ion (Ce3+) for the recognition of GSH over other available competitive amino acids (AAs) especially thiol species in aqueous media. Generally, cysteine (Cys) and homocysteine (hCys) can seriously interfere with the detection of GSH among common biological species because they possess similar chemical behavior. Using all the information from 1HNMR and FT-IR studies, the proposed interaction is presented in which GSH acts as a tri-dentate ligand with three N donor atoms in conjunction with BPR and XO as mono and bi-dentate ligands respectively. This approach opens a path for selective detection of other AAs by argumentatively selecting the ensemble of mixed organic ligands from commercially available reagents, thereby eliminating the need for developing synthetic receptors, sample preparation, organic solvent mixtures, and expensive equipment. Evaluating the feasibility of the existing method was led to the determination of GSH in human plasma samples.

Dye/metal ion-based chemosensing ensemble towards l-histidine and l-lysine determination in water via different optical responses.

In this study, a novel simple type of label-free, ultra-sensitive, and highly selective UV-Vis absorption and naked-eye detection of histidine (His) and lysine (Lys) using a dye/metal ion ensemble is developed. The outcoming high sensitivity and selectivity for histidine and lysine were attained by changing the metal ions. The indicator is released due to its displacement from the murexide (Mure)/Cu2+ complex by histidine and the change in absorbance may be due to the further complexation of lysine with the additional coordination sites present in the zinc atom of Mure/Zn2+ complex. The label-free chemosensor provided sensitive and selective detection of l-histidine and l-lysine with detection limits of 9.1 and 9.4 nmol L-1, respectively. The protocol especially offers high selectivity for the determination of His and Lys among amino acids found in human urine samples. Furthermore, INHIBIT and NAND molecular logic gates were obtained using chemical inputs and UV-Vis absorbance signal output.

Development of a Reversible Indicator Displacement Assay Based on the 1-(2-Pyridylazo)-2-naphthol for Colorimetric Determination of Cysteine in Biological Samples and Its Application to Constructing the Paper Test Strips and a Molecular-Scale Set/Reset Memorized Device.

A new colorimetric chemosensor for naked-eye detection and determination of cysteine (Cys) based on indicator displacement assay (IDA) was designed using 1-(2-pyridylazo)-2-naphthol (PAN). The indicator exchange occurred between PAN and Cys by the addition of Cys to the Cu(PAN)2 complex, which is accomplished by an immediate visible color change from magenta to yellow, in the solution phase and paper-based test strips. The proposed method exhibits 0.35 µmol L-1 detection limit and good linearity in the range of 2.25-42.91 µmol L-1. Paper test strips presented a detection limit of 38.0 µmol L-1, fabricating an easy to use test kit for compatible "in-the-field" detection of Cys. The computer image analysis of the paper test strips, obtained from the CMYK color analysis system, showed a linear increase in Y (yellow) intensity with enhancement in the Cys concentration of 50.0-550.0 µmol L-1. Additionally, the absorption and color change obtained in this chemosensor operate as an "INHIBIT" logic gate considering Cu2+ and Cys as inputs. Eventually, based on such a fast, reversible, and reproducible signal, a molecular-scale sequential memory unit was designed displaying "Writing-Reading-Erasing-Reading" and "Multi-Write" behavior. The developed chemosensor presented a satisfactory repeatability, intermediate precision, and successful application for the selective determination of Cys in human biological fluids. Graphical abstract .

A novel dye-based colorimetric chemosensors for sequential detection of Cu2+ and cysteine in aqueous solution.

An IDAs based chemosensing ensembles for sensitive and selective sequential detection of Cu2+ and cysteine (Cys) in 100% aqueous solution was designed on the basis of the complex formation between 4-(2-Pyridylazo)resorcinol (PAR). In the first step, PAR was used for colorimetric detection of Cu2+ in aqueous solution by the obvious color change. The detection limit (31.0 nmol L-1) for Cu2+ much lower than the guideline (31.5 µmol L-1) of WHO in drinking water. In the second step the produced ensemble (PAR-Cu2+), sensitively and selectively detected a low concentration of Cys via indicator displacement assay system. The detection limit for Cys was determined to be 72 nmol L-1. The colorimetric detection operation is low-cost using PAR and copper ion and has a simple operation without any further modifications. Any enzymatic reactions, separation processes, chemical modifications, and sophisticated instrumentations are also not required in this experiment. It could find applications for the detection of analytes in environmental, biological samples based on these results, dual logic gates (IMPLICATION and INHIBIT) were obtained by controlling the chemical inputs.

A reversible and dual responsive sensing approach for determination of ascorbate ion in fruit juice, biological, and pharmaceutical samples by use of available triaryl methane dye and its application to constructing a molecular logic gate and a set/reset memorized device.

Since dyes are available in huge quantities and have the well-established chemistry involved in their synthesis, their use in chemosensing could be continued. In the current study, a new and reversible colorimetric and fluorometric chemosensor based on available triaryl methane dye (brilliant green (BG)) - phosphotungstic acid (PTA) complex has been designed for determination of ascorbate (AscH-1) ion in water/DMSO (90:10v/v, 1.0mmolL-1 HEPES, pH7.0). The "ON-OFF" fluorescence and colorimetric responses of this ion association complex to AscH-1 were based on a displacement mechanism. For the detection of AscH-1, the linear ranges achieved for UV-Vis absorbance and fluorescence experiments were 3.9-62.6µmolL-1 and 1.9-85.4µmolL-1, respectively. The limits of detection for both of them were also calculated to be 0.4 and 0.2µmolL-1. The proposed method was also successfully utilized for rapid recognition of ascorbate in juice samples, human serum, and the formulation of supplement products. Moreover, the proposed chemosensor capability of functioning as INHIBITION-type sensor with PTA and AscH-1 as chemical inputs was indicated by the investigation of the molecular logic behavior of this chemosensor. Eventually, a sequential memory unit displaying "Write-Read-Erase-Read" function could be integrated based on the reversible and reproducible system.

Reactive Blue 4 as a Single Colorimetric Chemosensor for Sequential Determination of Multiple Analytes with Different Optical Responses in Aqueous Media: Cu2+-Cysteine Using a Metal Ion Displacement and Cu2+-Arginine Through the Host-Guest Interaction.

In the current study, we reported a novel label-free and facile colorimetric approach for the sequential detection of copper ion (Cu2+), L-arginine (Arg), and L-cysteine (Cys) in the H2O (10.0 mmol L-1 HEPES buffer solution, pH 7.0) using Reactive Blue 4 (RB4). First, the presence of Cu2+ led to a naked-eye color and spectral changes according to the binding site-signaling subunit approach. Then, the RB4-Cu2+ complex was successfully applied for Cys and Arg through different recognition pathways. The optical signals for Arg were observed due to its association involving the amino group, as well as the participation of the carboxylate group in a bidentate form to the complex, while selective behavior for Cys was explained by a metal displacement mechanism. The limits of detection for Cu2+, Arg, and Cys were calculated to be 1.96, 1.06, and 1.33 µmol L-1, respectively. It could also be employed for the determination of three analytes in environmental, biological, and pharmaceutical samples. Importantly, the test strips based on RB4-Cu2+ complex could be used as a solid-state sensor for the detection of Cys and Arg. In addition, NAND and IMPLICATION molecular logic gates were obtained by using chemical inputs and UV-Vis absorbance signal as the output. Graphical Abstract.

Development of a New Colorimetric Chemosensor for Selective Determination of Urinary and Vegetable Oxalate Concentration Through an Indicator Displacement Assay (IDA) in Aqueous Media.

The paper proposes a method that exhibits operational simplicity for the indirect spectrophotometric determination of oxalate ion. We developed Reactive Blue 4 (RB4) as a sensor by complexation with copper ion as a simple, inexpensive yet selective colorimetric chemosensing ensemble for the recognition of oxalate over other available competitive analytes via indicator displacement assay (IDA) in both solution (aqueous medium) and solid state (paper-based experiment). The addition of oxalate to RB4-Cu2+ complex changed the colour from sky blue to dark blue due to the regeneration of RB4 by the chelation of oxalate as the competitive analyte with Cu2+. The absorbance band increase is linear with oxalate concentration from 1.76 to 49.4 µmol/L with a detection limit of 0.62 µmol/L. This measurement mode did not show any influence of interferences (available anions and ascorbic acid). This approach eliminated the need for the separation stages, enzymatic multiple-step reactions, sample preparation, organic solvent mixture, chemical modifications and equipment developed to a high degree of complexity. The oxalate determination gave results in different real samples such as urine, mushroom and spinach, which demonstrated the applicability of the existing method. Furthermore, this colorimetric system can serve as IMPLICATION molecular logic gate using Cu2+ and oxalate (C2O4 2-) as inputs and UV-Vis absorbance signal as the output with potential monitoring applications.

Indigo Carmine-Cu complex probe exhibiting dual colorimetric/fluorimetric sensing for selective determination of mono hydrogen phosphate ion and its logic behavior.

A new selective probe based on copper complex of Indigo Carmine (IC-Cu2) for colorimetric, naked-eye, and fluorimetric recognition of mono hydrogen phosphate (MHP) ion in H2O/DMSO (4:1v/v, 1.0mmolL-1 HEPES buffer solution pH7.5) was developed. Detection limit of HPO42- determination, achieved by fluorimetric and 3lorimetric method, are 0.071 and 1.46µmolL-1, respectively. Potential, therefore is clearly available in IC-Cu2 complex to detect HPO42- in micromolar range via dual visible color change and fluorescence response. Present method shows high selectivity toward HPO42- over other phosphate species and other anions and was successfully utilized for analysis of P2O5 content of a fertilizer sample. The results obtained by proposed chemosensor presented good agreement with those obtained the colorimetric reference method. INHIBIT and IMPLICATION logic gates operating at molecular level have been achieved using Cu2+and HPO42- as chemical inputs and UV-Vis absorbance signal as output.

A novel and simple fluorescent and colorimetric primary chemosensor based on Congo-Red for sulfite and resultant complex as secondary fluorescent chemosensor towards carbonate ions: Fluorescent probe mimicking INHIBIT logic gate.

A simple receptor based on Congo-Red (CR) was prepared by complexation of CR into two equivalents of Cu (II) ([CR-(Cu)2]) and it has been designed for detection of sulfite and carbonate ions. This chemosensor exhibits high sensitivity for sulfite over other anions in aqueous buffer solution. It exhibits colorimetric 'naked eye' and fluorometric responses to SO3(2-) which results from the addition of SO3(2)(-) to CR diazo moiety. Hereupon, CO3(2-) greatly limits the fluorescence of the resultant sulfite-receptor complex via a hydrogen bonding interaction ([CR-(Cu)2]-SO3). This system can be applied for selective detection of CO3(2-) in the presence of other anions. The detection limits of SO3(2-), calculated by the colorimetric and fluorometric methods, were found to be 0.07 and 0.09µmolL(-)(1), respectively. The sulfite-receptor complex also displayed the ability to detect up to 0.06µmolL(-)(1) CO3(2-). The fluorescence output mimicked 'INHIBIT' logic gate function. The output was exhibited by the intramolecular charge transfer of the [CR-(Cu)2] probe, and was provided by chemical inputs (SO3(2-) and CO3(2-)).

An efficient and ultrasensitive rhodamine B-based reversible colorimetric chemosensor for naked-eye recognition of molybdenum and citrate ions in aqueous solution: sensing behavior and logic operation.

In this paper we manifest a novel rhodamine B (RhB) based colorimetric chemosensor for molybdenum and citrate ions (Cit(3-)) in an absolutely aqueous media. It has been identified as highly sensitive probe for Mo(6+) which responds at 4.0 nmol L(-1) concentration levels. RhB while combined with Mo(6+) in aqueous solution displays a color changing from pink to purple which could be quickly dissociated by the addition of citrate in this system so that reversible color changes from purple to pink can be achieved. The comparison of this method with some other methods for citrate indicates that this is the only method which can detect citrate in aqueous solution by color changes. This chemosensor can be applied for quantification of citrate with a linear range covering from 1.67×10(-7) to 1.22×10(-5) M and a detection limit of 2.0×10(-8) M. Moreover, the response of the chemosensor toward Mo(6+) and citrate is fast. In addition, based on above sensing mechanism, an IMPLICATION logic operation can be achieved using Mo(6+) ion and Cit(3-) as the inputs, making RhB a promising candidate for further applications in molecular logic devices and also indicates that RhB is suitable for the detection of Mo(6+) and Cit(3-) ions in real samples.

Determination of ammonia by designing an optode based on immobilization of a Co(III)-Schiff base complex on a triacetylcelluose membrane.

A novel ammonia optode was designed using [4-methyl-N,N'-bis(salicylidene)-1,2-phenylenediamine] tributylphosphincobalt(III) perchlorate monohydrate [Co(4-MeSaloph)(PBu)3]+ complex coated on a triacetylcellulose membrane. The sensor could be used at a wavelength of 378 nm to detect ammonia in the range of 8.3 x 10(-4) and -1.25 x 10(-2) M in borate buffer (pH 10). The LOD was found to be 9.5 x 10(-5) M. The response time of the optode was 2-3 min and depended on the concentration of ammonia. This optode was successfully applied for the determination of ammonia in drinking water.

A novel cyanide-selective colorimetric and fluorescent chemosensor: first molecular security keypad lock based on phosphotungstic acid and CN- inputs.

Rhodamine B (RhB) an available dye has been developed as novel and efficient colorimetric and fluorometric chemosensor for cyanide ions in an absolutely aqueous media. The UV-vis absorption and fluorescent emission titrations experiments have been employed to study the sensing process. RhB could act as an efficient "ON-OFF" fluorescent response for phosphotungstic acid (H3PW12O40 or PTA) based on an ion associate process. Also (RhB(+))3 · PTA(3-) could operate as an "OFF-ON" fluorescent sensor for cyanide anions based on a ligand substitution process. It has been identified as highly sensitive probe for CN(-) which responds at 0.3 and 0.04 µmol L(-1) concentration levels by absorption and fluorescent method respectively. Depending upon the sequence of addition of PTA and CN(-) ions into the solution, RhB could be as a molecular security keypad lock with PTA and CN(-) inputs. The ionic inputs to new fluorophore have been mimicked as a superimposed electronic molecular keypad lock. The results were compared successfully (>96%) with the data of a spectrophotometry approved method (EPA 9014-1) for cyanide ions.

Dithizone as novel and efficient chromogenic probe for cyanide detection in aqueous media through nucleophilic addition into diazenylthione moiety.

A new selective chemodosimeter probe was developed by the introduction of dithizone (DTZ) as a simple and available dye for detection of cyanide in aqueous media which enables recognition of cyanide over other competing anions such as acetate, dihydrogen phosphate, fluoride and benzoate through covalent bonding. The sensing properties of DTZ were investigated in DMSO/H2O (1:9) and have demonstrated a very high selectivity toward the cyanide anions. A reasonable recognition mechanism was suggested using UV-Vis, (1)H NMR and FTIR spectroscopy techniques. Time dependent density function theory (TDDFT) computations of UV-Vis excitation for DTZ2-CN adduct agreed well with our experimental findings. The detection limit of the new chromogenic probe was measured to be 0.48 µmol L(-1) which is much lower than most recently reported chromogenic probes for cyanide determination. The analytical utility of the method for the analysis of cyanide ions in electroplating wastewater (EPWW), human serum, tap and mineral water samples was demonstrated and the results were compared successfully with the conventional reference method. The short time response and the detection by the naked eye make the method available for the detection and quantitative determination of cyanide in a variety of real samples.

A novel development of dithizone as a dual-analyte colorimetric chemosensor: detection and determination of cyanide and cobalt (II) ions in dimethyl sulfoxide/water media with biological applications.

The behavior of dithizone (DTZ), an easily available dye has been studied for the first time in chromogenic sensing of CN(-) as an anionic species and for Co(2+) as a cationic species in DMSO/H2O media. So employing DTZ an efficient colorimetric chemosensor was afforded with a chromogenic selectivity for Co(2+) over other cations with detection limit of 0.04 µmol L(-1). The complex of Co(2+) with DTZ also displayed ability to detect up to 0.43 µmol L(-1) CN(-) (K(+) salts) among other competing anions through a fast response time of less than 30s which is much lower than most recently reported chromogenic probes. The linear dynamic ranges for the determination of Co(2+) and CN(-) were 0.3-4.4 and 3.3-58.6 µmol L(-1) respectively. This method could have potential application in a variety of cases requiring rapid and accurate analysis of Co(2+) and CN(-) for human serum and water samples.

Preconcentration and speciation of Cr(III) and Cr(VI) in water and soil samples by spectrometric detection via use of nanosized alumina-coated magnetite solid phase.

A novel nanomaterial has been developed for speciation of Cr(III) and Cr(VI) in water and soil samples. In this study, a new type of alumina-coated magnetite nanoparticles (Fe3O4/Al2O3 NPs) modified by the surfactant Triton X-114 has been successfully synthesized and used in magnetic mixed hemimicelles solid-phase extraction procedure. The procedure was based on the reaction of chromium(III) with 1-(2-pyridilazo)-2-naphtol as a ligand, yielding a complex, which was entrapped "in situ" in the surfactant hemimicelles. The concentration of chromium(III) was determined using flame atomic absorption spectrometry. After reduction of Cr(VI) to Cr(III) by ascorbic acid, the system was applied to the total chromium. Cr(VI) was then calculated as the difference between the total Cr and the Cr(III) content. This method can also be used for complicated matrices such as soil samples without any special pretreatment. Under the optimum conditions of parameters, the recoveries of Cr(III) by analyzing the spiked water and soil samples were between 98.6 and 100.8 % and between 96.5 and 100.7 %, respectively. Detection limits of Cr(III) were between 1.4 and 3.6 ng mL(-1) for water samples and 5.6 ng mg(-1) for soil samples.

Spectrophotometric simultaneous determination of orotic acid, creatinine and uric acid by orthogonal signal correction-partial least squares in spiked real samples.

An orthogonal signal correction-partial least squares (OSC-PLS) method was developed for the simultaneous spectrophotometric determination of orotic acid (OA), creatinine (CRE), and uric acid (UA) in spiked real samples. By multivariate calibration methods, such as PLS regression, it is possible to obtain a model adjusted to the concentration values of the mixtures used in the calibration range. The effect of OSC used to remove the information unrelated to the target variables is studied. In this study, the calibration model is based on absorption spectra in the 220-320 nm rang for 36 different mixtures of OA, CRE and UA. Calibration matrices contained 1.74-47.00 of OA, 1.13-33.95 of CRE, and 1.68-28.58 of UA in µg/ml. The number of principal component for OA, CRE, and UA with OSC were 3, 4, and 4, and 4, 6, and 5, without OSC, respectively. The evaluation of the prediction errors for the prediction set reveals that the OSC-treated data give substantially lower root mean square error of prediction (RMSEP) values than the original data. The RMSEP for OA, CRE, and UA with OSC were 0.69, 0.20, and 0.53 and 0.80, 0.69, and 0.73 without OSC, respectively. The proposed method was applied for the simultaneous determination of OA, CRE, and UA in spiked biological fluids with satisfactory results.

Cloud point extraction-atomic absorption spectrometry for pre-concentration and determination of cadmium in cigarette samples.

A new complexing agent, 2-((2-((1H-benzo[d]imidazole-2yl)methoxy)phenoxy)methyl)-1H-benzo[d]imidazole (BIMPI), was used in cloud point extraction and applied for selective pre-concentration of trace amounts of cadmium in cigarette samples. Cadmium was complexed with BIMPI in a buffer solution (pH = 10) using Triton X-114 as surfactant and quantitatively extracted into a small volume of the surfactant-rich phase after centrifugation. Under optimized conditions (pH = 10.0, 0.8 × 10(-4) mol L(-1) BIMPI and 0.08 % (w/v) Triton X-114), calibration graph was linear in the range of 34.0-1,670.0 µg L(-1). The proposed method was applied to the determination of Cd in various cigarette (tobacco) samples which gave satisfactory results.