Effects Of pH Conditions Research Articles

Effect of Specified pH Conditions on Leaching of Environmentally Important Major and Trace Elements from Fly Ash-Marl Mixtures: A Case Study of the Lignite Center of W. Macedonia

Significant environmental issues concerning the risk of soil, surface, and groundwater pollution are indicated by the presence of dissolved elements in the leachates. In the Lignite Center of Western Macedonia, the current study investigates the leaching behavior of main and trace elements from fly ash-marl mixtures, focusing on the effect of pH conditions on environmental impacts. Five mixtures of fly ash-marl were prepared in different percentage ratios by weight, simulating the possible deposition conditions to investigate the leaching of their contents in specified pH conditions. Initial fly ash is enriched in CaO, SO3, P2O5, and MgO, exceeding continental crust average composition in U, Br, Sb, Ni, Cd, W, and Mo. In contrast, the original marl is enriched in CaO and Ni but depleted in other major elements. The pH significantly affects leaching, with high concentrations of Ca2+ both in fly ash and in mixtures with high concentrations of fly ash, particularly at pH 8. Significant leaching of Cr and Ni is observed, with Cr mainly from fly ash at pH 10–12 and Ni increasing in marl at pH 6. The findings highlight the significant role of fly ash in the environmental element release and the importance of effective management.

Whey protein isolate-tamarind seed gum complexes stabilized dysphagia friendly high internal phase emulsions: The effects of pH conditions and mass ratios

Dysphagia is a common malfunction affecting a large population worldwide, yet the range of food available to the patients is limited. The objective of this study was to utilize a complex of whey protein isolate (WPI) and tamarind seed gum (TG) as novel emulsifiers to stabilize HIPEs, and further explore WPI-TG-based HIPEs' potential as dysphagia-friendly foods for special medical purposes (FSMP). The results indicated that WPI-TG forms complexes through hydrogen bonding and electrostatic interactions (pH 3 and 4). Additionally, TG induced changes in the secondary and tertiary structures of WPI. The particle size of HIPEs prepared from WPI-TG complexes was found to be reduced. Meanwhile, with the decrease in pH from 7 to 3, the variation in complexes ζ-potential led to an initial increase followed by a subsequent drop in the particle size of HIPEs. The rheological results indicated that WPI-TG-based HIPEs exhibit low-risk swallow characteristics, including shear thinning, high storage modulus, and good recovery ability. Further analysis using the IDDSI testing demonstrated that WPI-TG-based HIPEs under pH 3 and 4 can potentially be dysphagia-friendly FSMPs. After undergoing thermal treatment or long-term storage, WPI-TG-based HIPEs at pH 3 and 4 consistently maintained compliance with the IDDSI testing. These findings provided valuable insights for the future utilization of HIPEs in developing dysphagia-friendly FSMPs.

PH-induced changes in IgE molecules measured by atomic force microscopy.

The environment surrounding proteins is tightly linked to its dynamics, which can significantly influence the conformation of proteins. This study focused on the effect of pH conditions on the ultrastructure of Immunoglobulin E (IgE) molecules. Herein, the morphology, height, and area of IgE molecules incubated at different pH were imaged by atomic force microscopy (AFM), and the law of IgE changes induced by pH value was explored. The experiment results indicated that the morphology, height and area of IgE molecules are pH dependent and highly sensitive. In particular, IgE molecules were more likely to present small-sized ellipsoids under acidic conditions, while IgE molecules tend to aggregate into large-sized flower-like structures under alkaline conditions. In addition, it was found that the height of IgE first decreased and then increased with the increase of pH, while the area of IgE increased with the increase of pH. This work provides valuable information for further study of IgE, and the methodological approach used in this study is expected to developed into AFM to investigate the changes of IgE molecules mediated by other physical and chemical factors. RESEARCH HIGHLIGHTS: The ultrastructure of IgE molecules is pH dependent and highly sensitive. IgE molecules were tend to present small-sized ellipsoids under acidic pH. Alkaline pH drives IgE self-assembly into flower-like aggregates.

Formation mechanism of quinoa protein hydrolysate-EGCG complexes at different pH conditions and its effect on the protein hydrolysate-lipid co-oxidation in emulsions

This study aimed to investigate the interaction, structure, antioxidant, and emulsification properties of quinoa protein hydrolysate (QPH) complexes formed with (−)-epigallocatechin gallate (EGCG) at pH 3.0 and 7.0. Additionally, the effect of pH conditions and EGCG complexation on protein hydrolysate-lipid co-oxidation in QPH emulsions was explored. The results indicated that QPH primarily interacted with EGCG through hydrophobic interactions and hydrogen bonds. This interaction led to alterations in the secondary structure of QPH, as well as a decrease in surface hydrophobicity and free SH content. Notably, the binding affinity between QPH and EGCG was observed to be higher at pH 7.0 compared to pH 3.0. Consequently, QPH-EGCG complexes exhibited more significant enhancement in antioxidant and emulsification properties at pH 7.0 than pH 3.0. The pH level also influenced the droplet size, ζ-potential, and interfacial composition of emulsions formed by QPH and QPH-EGCG complexes. Compared to QPH stabilized emulsions, QPH-EGCG stabilized emulsions were more capable of mitigating destabilization during storage and displayed fewer lipid oxidation products, carbonyl generation, and sulfhydryl groups and fluorescence loss, which implied better oxidative stability of the emulsions. Furthermore, the QPH-EGCG complexes formed at pH 7.0 exhibited better inhibition of protein hydrolysate-lipid co-oxidation. Overall, these findings provide valuable insights into the potential application of QPH and its complexes with EGCG in food processing systems.

Tunable rheological properties of high internal phase emulsions stabilized by phosphorylated walnut protein/pectin complexes: The effects of pH conditions, mass ratios, and concentrations

The current study reported high internal phase emulsions (HIPEs) stabilized by phosphorylated walnut protein/pectin complexes (PWPI/Pec) and elucidated how their rheological properties were modulated by pH conditions, mass ratios, and concentrations of the complexes. At pH 3.0, the HIPEs stabilized by PWPI/Pec exhibited smaller oil droplet sizes, as well as higher storage modulus (G') and flow stress, in comparison to those stabilized by the complexes formed at pH 4.0–6.0. These observations can be directly linked to pH-dependent changes in particle size, surface hydrophobicity, and wettability of the PWPI/Pec complexes. Rheological analysis revealed that all generated HIPEs displayed weak strain overshoot behavior, irrespective of pH conditions. Notably, HIPEs stabilized by PWPI/Pec at mass ratios of 2:1 and 4:1 showed enlarged oil droplet sizes, lower G' and flow stress but higher flow strain with unaffected loss factor compared to those stabilized by PWPI/Pec 1:1. However, reducing the concentration of PWPI/Pec led to a simultaneous decrease in G', flow stress, and flow strain, along with a significant increase in the loss factor of the HIPEs. Furthermore, the HIPEs formed with 1% PWPI/Pec 1:1 at pH 3.0 demonstrated excellent stability against heat treatment and long-term storage. These results provide valuable insights into the modulation of rheological characteristics of HIPEs and offer guidance for the application of walnut protein-based stabilizers in HIPE systems.

Investigation of starch as flocculant for removing oil from oily wastewater

The treatment of oil-containing wastewater was carried out in 3 stages coagulation, neutralization, and flocculation processes. In this study, natural flocculants that are alternatives to polyacrylamide (PAM), have been investigated, as PAM poses a danger to drinking water and aquatic organisms. Flocculant properties were given to starch by modification, pregel, and graft methods, and flocculation results were examined. Oil content and pollution removal performances from wastewater were evaluated with the flocculant effect, the effect of pH conditions, dosage amounts, and temperature parameters. Since the chemical flocculants used in the flocculation sedimentation process to treat oily wastewater cause environmental damage, a natural flocculant effect study was carried out. The effect of starch flocculants synthesized by pregel, modified, and graft techniques on the oily wastewater, bilge water, was evaluated. In this context, the interaction of the effects of PAM, Pregel starch, modified starch and starch graft acrylamide flocculants on the bilge water with different ambient pH, dosage amount and temperature are included. Impact assessment at 5.5–7-8.5 ambient pH for 4 different flocculants; The effect evaluation of 10–15–25 mL dosage amounts and the effect evaluation at 25–40–60 °C temperatures were investigated by experimental studies. Suspended solids analysis, COD, Turbidity and oil-grease determinations are the analyses made for the improvement results in water due to impact assessments. According to the results obtained, it is a flocculant-modified starch that can compete with PAM but needs further development. 98.14 % suspended solids removal, 34.30 % COD removal, 98.94 % turbidity removal and approximately 99.9 % oil removal efficiency were obtained with modified starch.

Low density lipoprotein-pectin complexes stabilized high internal phase pickering emulsions: The effects of pH conditions and mass ratios

The present work aimed to explore the feasibility of using egg yolk low density lipoproteins (LDL) as naturally occurring nanoparticles to prepare high internal phase Pickering emulsions (HIPEs), and to understand the role of pectin (PE) as a natural food thickener in improving the emulsifying stability to prepare HIPEs. Colloidal complexes were formed spontaneously via electrostatic interactions upon mixing PE and LDL at acidic pH condition. The colloidal characteristics of LDL-PE complexes were studied by dynamic light scattering method, Fourier transform infrared spectroscopy and viscosity measurements, as well as interfacial activities. Lastly, the capability of complexes as a stabilizer to prepare HIPEs was then comprehensively investigated as functions of pH conditions and mass ratios of LDL and PE. The results indicated that the particle sizes and surface activities of LDL-PE complexes were highly dependent on the electrostatic interactions. The interactions between LDL and PE slightly reduced at neutral pH conditions or higher concentrations of PE, which were more favorable to form stable particles with smaller size and higher surface activity, and thus greater stability of HIPEs. Although the interfacial tensions of LDL increased with the existence of PE, the stability of LDL-PE stabilized HIPEs (LP-HIPEs) was greatly enhanced compared with the free LDL stabilized ones. LDL and PE formed non-covalent network among the emulsion droplets and the oil-water interface of HIPEs, inducing stable gel structure. Droplet size analysis and morphological observation under optical microscopes together with digital photos revealed the homogenous emulsion droplets in a strong gel geometry. Gel-like elastic network structure was confirmed by rheological measurements, and the thick coating layer of LDL-PE complexes on the oil-water interface was further visualized by confocal laser scanning microscope. Our findings are innovative and offer new opportunities to prepare HIPEs from all natural ingredients for future applications in the food industry. • Low density lipoprotein-pectin (LDL-PE) complexes were able to stabilize HIPEs. • Pectin played critical roles in the formation of stable gel-like structure in HIPEs. • Rheological data and microscopical images confirmed the strong gel network. • The HIPEs showed exceptional stability in centrifugation and long-term storage tests. • LDL-PE exhibited superior emulsifying and stabilization capability than LDL alone.

Effect of pH Condition and Different Solution on the Slake Durability of Granitic Rocks

Effect of pH Condition and Different Solution on the Slake Durability of Granitic Rocks

Effect of pH condition during sol-gel synthesis on the volume fraction of hydroxyapatite from sea coral

A research Hydroxyapatite synthesis has been carried out using the sol-gel method with variations in acidity (pH). Hydroxyapatite sources are obtained from marine corals from Banyuwangi. Hydroxyapatite synthesis is carried out by reacting calcium hydroxide Ca(OH)2 obtained from the powder coral with phosphoric acid (H3PO4) using the sol-gel method. synthesis is carried out with a pH variation from values 5 to 13 at intervals of 2 and is characterized using XRD (X-Ray Diffractometer). The XRD results show that for hydroxyapatite synthesis using the sol gel method the most optimal pH value is 11 with a volume fraction of 92.7% and the impurities are Lime CaO and Portlandite Ca(OH)2.

Effectiveness of Ozonation Process on Treating Tofu Industrial Liquid Waste: Effect of pH Conditions

The tofu industries in Indonesia produce a considerable amount of liquid waste. Most of these tofu industries do not treat waste properly. Liquid waste is channeled directly to the nearest water stream, and thus the values of COD, BOD and TSS are considerably high, which can damage the aquatic ecosystems. According to the Indonesian government rule (Permen LH no.5/2014), the maximum levels of COD, BOD and TSS are 300 mg/L, 150 mg/L, and 200 mg/L. One of alternative methods to reduce these three parameters is the ozonation method. Ozone is able to break down organic components well because of its strong oxidative properties (2.07 mV) and it can decompose into OH radicals which have stronger oxidative properties (2.80 mV). The objectives of this study are to reduce the levels of COD, BOD and TSS of tofu liquid waste into below of the maximum level set by the Indonesian government rule and to study the effect of pH conditions on the effectiveness of ozonation process. Ozonation is carried out under conditions at acidic pH, alkaline pH, and neutral pH, and with a waste concentration of 10%. Ozonation is done by flowing ozone directly into the waste for 120 minutes with an interval of 30 minutes. The levels of BOD, COD, and TSS before ozonation were 1,200 mg/L, 880 mg/L and 600 mg/L. After ozonation, it was found that the levels of COD, BOD and TSS of the waste without any pre-treatment (or acidic condition) was able to be reduced by 46.6%, 44.5% and 41.6%, respectively. Whereas, in neutral conditions the decreases of COD, BOD, and TSS were about 64.3%, 67.0%, and 62.4%, respectively. Optimum ozonation was found in alkaline conditions with the decreases in COD, BOD, and TSS values were about 85.4%, 84%, and 100%, respectively.

A study on the effect of pH conditions on the properties of self-healing mortar cubes

This paper discusses the effect of pH on the various properties of the self-healing mortars (SHM). The bacteria induced structures have the ability to heal cracks generated on its surfaces by precipitating minerals inside the pores which bio mimics the natural healing processes occurring in nature, thus being an environment friendly technology that contributes in maintaining the structural durability. The microbiologically induced precipitation accelerates at different rates at different conditions. Hence an attempt has been made to analyse the changes in the properties in mortar cubes induced with 105 cells/ml concentration of Bacillus megaterium solution and subjecting them to different curing media at different pH conditions. The healing efficiency of the cracks induced in the mortar cubes are evaluated visually for successive days. Through X-ray Diffraction analysis the white powder covering crack surface is confirmed to be calcite. The percentage reduction in the compressive strength of the samples after healing was found to be only 3% after 28 days of curing. The findings of the paper suggest promising application of self-healing mortar cubes at different geographical locations by varying the amount of bacterial solution.

Evaluation of Corrosion of a Fe-40Al-2RE Intermetallic Alloy in NS4 Solution

The corrosion study of Fe-40Al+2% Rare Earths (RE) intermetallic alloy in NS4 solution at room temperature was carried out. The intermetallic alloy was previously produced by melting in an induction furnace. The alloy microstructure is constituted by a minority phase of Fe3Al, homogeneously dispersed in the majority phase of FeAl. The effect of pH condition was presented in the corrosion mode, at pH 5 the sample showed uniform corrosion, while at pH 3 and 7 some pitting sites were observed, however the metallic samples showed uniform corrosion on the exposed areas. The anodic dissolution mechanism occurred preferentially in the FeAl phase observed at pH 3, which corresponds to the majority phase or alloy microstructure. Electrochemical results were complemented with the microstructure and chemical characterization by scanning electron microscopy, energy dispersion spectroscopy and X-ray diffraction analysis.

Effects of pH Conditions and Application Rates of Commercial Humic Substances on Cu and Zn Mobility in Anthropogenic Mine Soils

We studied the effects of commercial humic substances derived from leonardite at different rates (0, 0.25, 2, 10 g kg−1) and pH (4.5, 6.0, 8.0) on Cu and Zn mobility, to evaluate their use for remediation of metal contaminated mine soils and to optimize their application conditions. We conducted a single-step extraction experiment and analyzed extracts for metal concentrations, soluble organic carbon and their E4/E6 ratio (ratio of absorption at 465 to 665 nm). Metal speciation in a soil solution was simulated by the non-ideal competitive adsorption-Donnan (NICA-Donnan) model. Increasing the amount of humic substances and the pH caused higher release rates of soluble organic carbon with a lower humic/fulvic acids ratio. This led to a higher mobility of metals (up to 110 times Cu concentration in control and 12 times for Zn) due to the formation of soluble metal-humic complexes. Speciation modeling predicted that increasing rates of humic substances would result in a higher proportion of Cu and Zn associated with fulvic acids, more mobile than the humic acids fraction. Application of commercial leonardite humic substances at 2–10 g kg−1 and with pH levels similar to or below natural soil could be useful for assisted-phytoextraction of contaminated anthropogenic soils. High rates of humic substances in more alkaline conditions could entail a considerable risk of metal leaching to groundwater, toxicity and transfer to the trophic chain.

Effect of pH condition during hydrothermal synthesis on the properties of hydroxyapatite from eggshell waste

Hydroxyapatite (HA) powders were synthesized using eggshell waste through hydrothermal method to develop bioceramics materials for medical applications. The effects of the pH conditions during the synthesis on the phase behaviour, crystallite size, crystallinity and morphology of as-synthesized ceramic powders were evaluated. The XRD patterns showed that HA was only the main phase present in the as-synthesized powder after being calcined at 400°C. However, EDX measurement detected the presence of Mg as trace elements which originated from the eggshell as starting materials. The crystallite size and crystallinity of the HA powders were increased when the powders were synthesized in acidic condition as compared to basic condition. FESEM images showed that HA powder with nano-sized rods and spherical morphologies were obtained from the powders that were synthesized at pH 5, while the powder particles synthesized at basic condition at pH 9 produced elongated rod-shape particles. The PSD results showed that the synthesized HA were in agglomerated form which were also confirmed by FESEM images.

Lactic acid fermentation of dahlia tuber starch and waste using Lactobacillus bulgaricus: A comparative study

Lactic acid fermentation of dahlia tuber starch and waste was performed by means of Lactobacillus bulgaricus through enzymatic hydrolysis followed by fermentation process. The effect of pH condition on lactic acid production was investigated during the process. The selected bacteria produced lactic acid after 24 hours of fermentation and the productivity was increase after 24 hours of fermentation. After 120 hours of fermentation, it was found that dahlia tuber starch can produce up to 16.18% of lactic acid, whereas lactic acid produced from dahlia tuber waste was only 0.40% at pH of 4. The lactic acid production increase significantly for pH 3.5 and 4 until 96 hours of fermentation, then slowed down. On the other hand, for pH 4.5 the lactic acid production increase until 48 hours of fermentation and then slowed down. The identification of fermentation product indicated that the lactic acid produced in this study was 16.20%, acidic, yellow and cloudy with pH 3.4 – 4.2. The density of lactic acid produced ranged between 1.21 to 1.25 gr/ml.

Controlled synthesis of blue spherical CoAl2O4 pigment powder in Pickering emulsion assisted with a hydrothermal process

A spherical blue CoAl2O4 pigment powder commonly used for coloring ceramic products has successfully been synthesized by co-precipitation of Co2+ and Al3+ ions in Pickering emulsion assisted with a hydrothermal process, and the formation mechanism of the as-prepared powder has briefly been discussed. The effects of pH condition on the crystalline phase and color tone of the pigment powder were investigated at 280 °C by varying the pH value of the reaction system. Then, under an optimized pH condition to produce blue, the pigment powder was synthesized still hydrothermally at different temperatures (210, 240, 270 and 300 °C) to assess the effect of hydrothermal reaction temperature on the pigment particle morphology. The resulting pigment powders were characterized by field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), CIELAB colorimetric analysis (CIE-L∗a∗b∗), laser particle size analysis (LPS), and N2-adsorption measurement (BET). FE-SEM and TEM observations indicated that the pigment powders of spherical shape obviously were constructed by a core–shell double-layer structure, the radii of which all were ∼150 nm or so with a shell of ∼25 nm in thickness. XRD results demonstrated that the pigment powders that were obtained from the aforementioned method under a wide range of pH values invariably contained basically crystalline CoAl2O4 of high purity. CIE-L∗a∗b∗ data suggested that the pigment powders at 280 °C and pH ≤ 11.2 appeared different chromas of bluish colors compared withthat displaying black which was obtained at pH = 12.3. LPS and BET results showed that the CoAl2O4 pigment powder prepared under the urea concentration of 3.6040 g for 24 h at the hydrothermal temperatures of 240 °C exhibited a narrow particle size distribution, the specific surface area of which was evaluated to be ∼56.4 m2/g.

Effect of pH conditions on the depolymerization of Wucaiwan coal by mixed acids/ultrasound method and the product structures and performance

The cleavage of the aliphatic chain or ether bond connecting the polycyclic aromatic hydrocarbons in coal can be achieved by not only hydrogenation reduction but also oxidative acid treatment. In this paper, coal samples from Wucaiwan in Xinjiang were pretreated with HNO3 followed by mixed acids/ultrasound treatment. The depolymerized coal samples obtained under different pH conditions were then separated by fractional washing. The structures and properties of the resulting coal samples were studied by elemental analysis, FT-IR, XRD, TG–DTA, TEM, UV–Vis, and PL. The results showed that when pH = 0.012, the obtained coal samples were fragments stripped off from the raw coal samples by ultrasound in strong acid conditions, aliphatic hydrocarbons linked with oxygen-containing groups such as nitro group, a small amount of small aromatic molecules and mineral salts; when pH = 1.99–4.09, the obtained coal samples were polycyclic aromatic hydrocarbons linked with oxygen-containing groups such as nitro group,possessing the annulus wall of multilayer graphene fragment structures built up by sp2 carbons, and they are typical fluorescent substances of carbon nanoparticle structure. The former has no solubility in organic solvents, while the latter can be well dissolved in polar solvents such as acetone. All the depolymerized coal samples obtained under different pH conditions exhibited good absorption and ability of fluorescence emission.Graphical

Assessments of the disintegrating behaviour of clay shale considering the effect of pH condition

In this paper, several disintegration tests were conducted in different acid and alkali solutions and their results were analysed. A theoretical model based on the principle of similarity and the conservation of mass were proposed to describe the relationship between the number of disintegration cycles and the particle size distributions. Using this model, the fractal evolution of the disintegration of clay shales under different pH conditions were evaluated and the results show that the fractal dimension of clay shale disintegration is greater at initial cycles in acidic solutions compared with that in alkaline solutions, All fractal dimensions, however, approach the same value given enough number of disintegration cycles but more cycles are needed in alkaline solutions for the value of fractal dimension to become stable. Another theoretical model was also proposed in this paper to evaluate the incremental surface energy and cumulative incremental surface energy of clay shale disintegration based on the principle of energy dissipation. And the relationships between the cumulative incremental surface energy and the pH value were obtained for the case study. It was found that all curves have the same attenuation trend, and the absolute incremental surface energy decreases as the disintegration cycle increases.

Graphene-based materials via benzidine-assisted exfoliation and reduction of graphite oxide and their electrochemical properties

Benzidine, a compound bearing aromatic rings and terminal amino groups, was employed for the intercalation and simultaneous reduction of graphite oxide (GO). The aromatic diamine can be intercalated into GO as follows: (1) by grafting with the epoxy groups of GO, (2) by hydrogen bonding with the oxygen containing groups of GO. Stacking between benzidine aromatic rings and unoxidized domains of GO may occur through π-π interaction. The role of benzidine is influenced by pH conditions and the weight ratio GO/benzidine. Two weight ratios were tested i.e. 1:2 and 1:3. Under strong alkaline conditions through K2CO3 addition (pH ∼10.4–10.6) both intercalation and reduction of GO via amino groups occur, while under strong acidic conditions through HCl addition (pH ∼1.4–2.2) π-π stacking is preferred. When no base or acid is added (pH ∼5.2) and the weight ratio is 1:2, there are indications that reduction and π-π stacking occur, while at a GO/benzidine weight ratio 1:3 intercalation via amino groups and reduction seem to dominate. The aforementioned remarks render benzidine a multifunctional tool towards production of reduced graphene oxide. The effect of pH conditions and the GO/benzidine weight ratio on the quality and the electrochemical properties of the produced graphene-based materials were investigated. Cyclic voltammetry measurements using three-electrode cell and KCl aqueous solution as an electrolyte gave specific capacitance values up to ∼178F/g. When electric double-layer capacitors (EDLC) were fabricated from these materials, the maximum capacitance in organic electrolyte i.e., tetraethyl ammonium tetrafluoroborate (TEABF4) in polycarbonate (PC) was ∼29F/g.

Surface plasmon resonance sensor based on molecularly imprinted polymer film for detection of histamine

The demand for advanced, sensitive, and low-cost sensor platforms is growing. However, sensors containing biological recognition elements sometimes present restrictions, which limit their use. This work focused on the development of surface plasmon resonance (SPR) based on a molecularly imprinted polymer (MIP) film, which builds a foundation for biomimetic sensors. The MIP films in the sensor chip were prepared by spin-coating method. The MIP film was found to be readily incorporated into the sensor for detection of histamine in aqueous media. The effect of pH conditions was also investigated. The sensing technique allows for the detection of histamine in a wide range of concentration from 25μgL−1 to 1000μgL−1. By using structural analogs, the sensor platform was demonstrated to be specific for the detection of histamine.