Blue Complex Research Articles

Photovoltaic Performance of Naphthol Blue Black Complexes and their Band Gap Energy

Along with the depletion of petroleum-based fuels, the development of renewable energy resources is a must. One of them is through DSSC (Dye Sensitized Solar Cells) technology, which has a dye sensitizer and semiconductor as the main components. The aim of this research is to investigating the photovoltaic performance of complexes series from metals (Mn(II); Fe(II); Co(II) and Ni(II)) and naphthol blue-black (NB) as a ligand. This investigation also successfully revealed factors that are highly influencing photovoltaic efficiency, namely the band-gap energy and the conductance of metal-NB complexes. The Fe(II)-NB complex has performed the highest photovoltaic activity as a result of the d-d electron transition and MLCT (Metal to Ligand Change Transfer) character which are covered by vivid color from the ligand. The bonding between metal and ligand was shown at a wavenumber of 316.33 cm-1 for M-N bonding and 486.06 cm-1 for M-O bonding. Fe(II)-NB complex had the narrowest band gap energy which is 5.86 eV and had the highest value of conductance and the highest efficiency, namely 0.0925%. This experiment successfully demonstrates that the narrower the energy gap of a molecule, the ability to transfer electrons is faster. Thus, the efficiency of the solar cell becomes higher. This investigation has proven that the narrow band gap makes the electron transfer becomes easier.

Little-Cost Potentiometric and Spectrophotometric Procedures for Cephalothin Assessment in Pure and Biological Fluids.

Low-cost potentiometric and spectrophotometric procedures for cephalothin (CPI) determination in pure and biological fluids were investigated. The potentiometric technique is created through titration of CPI with an aqueous medium of 0.1 M NaOH at an ionic strength of μ = 0.3 M sodium chloride and room temperature by a combined glass pH electrode. Using the standard addition method, we found that the detection and quantitative limits were 0.042 mg/mL, with the standard deviation SD = 0.011, correlation coefficient R = 0.9880 (n = 5), and linear concentration ranges from 0.042 to 0.82 mg/mL. This technique was utilized to assess CPI in pure solutions, urine, and serum with suitable results. No interference was exposed in the presence of public components of the samples under study. Recovery of CPI for pure and biological fluids is in the range of 98.2-101%. Also, the spectrophotometric method has been performed through the formation of the Prussian Blue (PB) complex. The reaction between the acidic hydrolysis product of CPI (T = 60 °C) and the mixture of Fe3+ with hexacyanoferrate (III) ions (HCF(III)) was detected for the spectrophotometric determination of the drug. The maximum absorbance of the formed complex was measured at λ = 283 nm with 2.0 × 103 L mol-1 cm-1 molar absorptivity. Reaction states have been advanced to acquire the PB complex of great sensitivity and longer stability. In optimal states, the absorbent of the PB compound was attained to grow linearly with the increase in the concentration of CPI, which agrees with the correlation coefficient values. The detection and quantitative limits were 0.000036 and 0.0012 mg/mL, respectively, with the standard deviation, SD = 0.0005, correlation coefficient, R = 0.9955 (n = 5), and the linearity range of the calibration plot 0.0005-0.02 mg/mL CPI. The planned technique was positively utilized for the detection of CPI in both urine and serum models. The results fit well with the data found from the potentiometric method.

The use of ultra-violet visible spectroscopy to determination some antibiotics beta-lactam in some drugs

This research aims to use chemical reaction to determine some of beta lactam antibiotics which include cephalexin and ceftriaxone in some pharmaceuticals by formation Prussian Blue complexes and using them for the UV-Vis., determination of drugs at wavelengths range (700- 720)nm by reaction them with FeCl3 in the presence of reagent K3[Fe(CN)6] in acid media . The optimal experimental conditions for the complex formation have been studied such as volume of HCl , K3[Fe(CN)6] , FeCl3 ,temperature and reaction time .Analytical figures of merits obtained on applying the developed procedure for cephalexin and ceftriaxone resp. are Linearity,(2-10),(1-7)?g.ml-1 LOD(0.0601,0.0330) ?g.ml-1. The developed procedure has been successfully applied to the determination of the antibiotics Cephalexin and Ceftriaxone in pharmaceutical preparations , Cephalexin and Gramocef using direct and standard additions method. The analytical results match well with the drug contents as indicated by recovery percent had been found as follows (103.50%,93.27%.) for cephalexin, and ceftriaxone resp..

Paper-based isotachophoretic preconcentration technique for low-cost determination of glyphosate.

Electrophoretic microfluidic paper-based analytical devices (e-µPADs) are promising for low-cost and portable technologies, but quantitative detection remains challenging. In this study, we develop a paper-based isotachophoretic preconcentration and separation method for the herbicide glyphosate as a model analyte. The device, consisting of two electrode chambers filled with leading and terminating electrolytes and a nitrocellulose strip as the separation carrier, was illuminated by a flat light source and operated with a voltage supply of 400V. Detection was accomplished using a simple camera. Colorimetric detection was optimized through competitive complexation between glyphosate, copper ions, and pyrocatechol violet as a dye. The buffer system was optimized using simulations, (i) ensuring the pH was optimal for the demetallation of the blue pyrocatechol violet-copper complex [PV] to the yellow free dye and (ii) ensuring the electrophoretic migration of glyphosate into the slower [PV] for the colorimetric reaction. A new data evaluation method is presented, analyzing the RGB channel intensities. The linear range was between 0.8 and 25µM, with a LOD of approximately 0.8µM. The ITP separation preconcentrated glyphosate by a factor of 820 in numerical simulations. The method may be applied to control glyphosate formulations, especially in developing countries where herbicide sales and applications are poorly regulated.

A Method for the Colorimetric Quantification of Sodium Lauryl Sulphate in Tablets: A Proof of Concept.

The deformulation stage of original drug products, which includes the quantification of critical excipients, is crucial for the successful development of generic drug products of solid dosage form. Sodium lauryl sulphate (SLS) belongs to the group of critical excipients due to its influence on the bioavailability of drugs, such as metformin. The purpose of this work is to carry out a feasibility study in order to develop a simple, economical, and robust analytical method for the quantification of SLS in metformin-containing tablets after their dissolution in water. Firstly, SLS is extracted with chloroform in acidic conditions, followed by the addition of methylene blue (MB) in order to form a SLS-MB ion pair, which is then measured photometrically at a wavelength of 651 nm. Additionally, interference from matrix components (excipients and APIs) was assessed, and it was found that metformin also forms a blue complex; therefore, this specific extraction method was developed. Other matrix components did not interfere with SLS determination. This method shows a well-estimated precision of 3.3% and accuracy of 5%, a calibration linearity of R2 = 0.99990, and a working range of 0.38 µg/mL to 10 µg/mL of SLS in water. The midpoint of the calibration graph corresponds to the concentration of SLS obtained by dissolving a single tablet in 1 L of water. This method seems appropriate for total SLS determination in tablets and can be applicable for deformulation.

Integrated Transcriptome and Metabolome to Elucidate the Mechanism of Aluminum-Induced Blue-Turning of Hydrangea Sepals

Hydrangea macrophylla is an ornamental plant with varied calyx colors. Interestingly, from red, to purple, to blue, the colors of all Hydrangea macrophylla are formed by unique delphinidin-3-O-glucoside and aluminum ions (Al3+) and 5-O-p-coumaroylquinic acid. The sepals of ‘Blue Mama’ changed from pink to blue, and the contents of delphinidin-3-O-glucoside and aluminum ions increased under 3 g/L aluminum sulfate treatment. However, the mechanism of the effect of aluminum ions on the synthesis and metabolism of anthocyanins in Hydrangea macrophylla is still unclear. In this project, transcriptome sequencing and anthocyanin metabolome analysis were performed on the sepals of ‘Blue Mama’ during flower development at the bud stage (S1), discoloration stage (S2) and full-bloom stage (S3) under aluminum treatment. It was found that delphinidin, delphinidin-3-O-glucoside and delphinidin-3-O-galactoside were the main differential metabolites. The structural genes CHS, F3H, ANS, DFR and BZI in the anthocyanin synthesis pathway were up-regulated with the deepening in sepal color. There was no significant difference between the aluminum treatment and the non-aluminum treatment groups. However, seven transcription factors were up-regulated and expressed to regulate anthocyanin synthesis genes CHS, F3H, BZI and 4CL, promoting the sepals to turn blue. The KEGG enrichment pathway analysis of differentially expressed genes showed that the glutathione metabolism and the ABC transporter pathway were closely related to anthocyanin synthesis and aluminum-ion transport. GST (Hma1.2p1_0158F.1_g069560.gene) may be involved in the vacuolar transport of anthocyanins. The expression of anthocyanin transporter genes ABCC1 (Hma1.2p1_0021F.1_g014400.gene), ABCC2 (Hma1.2p1_0491F.1_g164450.gene) and aluminum transporter gene ALS3 (Hma1.2p1_0111F.1_g053440.gene) were significantly up-regulated in the aluminum treatment group, which may be an important reason for promoting the transport of anthocyanin and aluminum ions to vacuoles and making the sepals blue. These results preliminarily clarified the mechanism of aluminum ion in the synthesis and transport of anthocyanin in Hydrangea macrophylla, laying a foundation for the further study of the formation mechanism of ‘blue complex’ in Hydrangea macrophylla.

Regulatory gene network for coffee-like color morph of TYRP1 mutant of oujiang color common carp

BackgroundNeither a TYRP1-mediated highly conserved genetic network underlying skin color towards optimum defense nor the pathological tendency of its mutation is well understood. The Oujiang Color Common Carp (Cyprinus carpio var. color) as a model organism, offering valuable insights into genetics, coloration, aquaculture practices, and environmental health. Here, we performed a comparative skin transcriptome analysis on TYRP1 mutant and wild fishes by applying a conservative categorical approach considering different color phenotypes.ResultsOur results reveal that an unusual color phenotype may be sensitized with TYRP1 mutation as a result of upregulating several genes related to an anti-inflammatory autoimmune system in response to the COMT-mediated catecholamine neurotransmitters in the skin. Particularly, catecholamines-derived red/brown, red with blue colored membrane attack complex, and brown/grey colored reduced eumelanin are expected to be aggregated in the regenerated cells.ConclusionsIt is, thus, concluded that the regenerated cells with catecholamines, membrane attack complex, and eumelanin altogether may contribute to the formation of the unusual (coffee-like) color phenotype in TYRP1 mutant.

Quantification of Total Phenol Concentration in Ethanol Extracts of Red and Black Betel Leaves Using UV-Vis Spectrophotometric Method

Red betel (Piper crocatum Ruiz & Pav) and black betel leaves (Piper betle var. nigra) are plant varieties known for their medicinal properties. These plants have various contents including flavonoids, essential oils, tannins and polyphenols. The objective of this research is to ascertain the quantity of phenolic compounds present in ethanol extracts of red and black betel leaves. Determination of the levels of ethanol extracts of red and black betel leaves is done quantitatively by the folin-ciocalteu method. This method relies on the formation of a blue complex compound of of phosphomolybdat-phosphotungstat, generated by the reduction of phenolic compounds in an alkaline environment. The measurement is performed using uv-vis spectrophotometry. Gallic acid, derived from hydroxybenzoic acid and identified as a simple phenolic acid, is employed. This stable and pure polyphenolic compound is commonly found in almost all plants. Drawing conclusions from the study results, it can be affirmed that the average total phenol concentration of red betel was 31.87 GAE per gram extract and the average total phenol concentration of black betel leaves was 39.09 mg GAE per gram extract.

45‐3: Molecular Design of Blue Phosphorescent Platinum Complexes for Highly Efficient, Long‐Lived Blue Organic Light‐Emitting Diodes

Our novel blue phosphorescent platinum complexes (BD‐01 and BD‐02) achieve high quantum yield and orientation. A BD‐02 organic light‐emitting diode (OLED) achieves an external quantum efficiency of 28.6% due to its inhibited interaction with a host molecule. This improved efficiency reduces the driving current of OLEDs and increases their lifetime.

Indoor-Light-Activated Blue TiO2-Molecule-WO3 Visible Photocatalyst for Antibacterial Performance against Escherichia coli.

Currently used visible light catalysts either operate with high-power light sources or require prolonged periods of time for catalytic reactions. This presents a limitation regarding facile application in indoor environments and spaces frequented by the public. Furthermore, this gives rise to elevated power consumption. Here, we enhance photocatalytic performance with blue TiO2 and WO3 complexes covalently coupled through an organic molecule, 3-mercaptopropionic acid, under indoor light. Antibacterial experiments against 108 CFU/mL Escherichia coli (E. coli) suspensions were conducted under indoor light exposure conditions. They showed a sterilization effect of almost 90% within 70 min and nearly 100% after 110 min. The complex generates reactive oxygen species (ROS), such as •OH and O2•-, under natural air conditions. We also showed that h+ and •OH are important for sterilizing E. coli using common scavengers. This research highlights the potential of these complexes to generate ROS, effectively playing a crucial role in antibacterial effects under indoor light.

Transgressive gene expression and expression plasticity under thermal stress in a stable hybrid zone.

Interspecific hybridization can lead to myriad outcomes, including transgressive phenotypes in which the hybrids are more fit than either parent species. Such hybrids may display important traits in the context of climate change, able to respond to novel environmental conditions not previously experienced by the parent populations. While this has been evaluated in an agricultural context, the role of transgressive hybrids under changing conditions in the wild remains largely unexplored; this is especially true regarding transgressive gene expression. Using the blue mussel species complex (genus Mytilus) as a model system, we investigated the effects of hybridization on temperature induced gene expression plasticity by comparing expression profiles in parental species and their hybrids following a 2-week thermal challenge. Hybrid expression plasticity was most often like one parent or the other (50%). However, a large fraction of genes (26%) showed transgressive expression plasticity (i.e. the change in gene expression was either greater or lesser than that of both parent species), while only 2% were intermediately plastic in hybrids. Despite their close phylogenetic relationship, there was limited overlap in the differentially expressed genes responding to temperature, indicating interspecific differences in the responses to high temperature in which responses from hybrids are distinct from both parent species. We also identified differentially expressed long non-coding RNAs (lncRNAs), which we suggest may contribute to species-specific differences in thermal tolerance. Our findings provide important insight into the impact of hybridization on gene expression under warming. We propose transgressive hybrids may play an important role in population persistence under future warming conditions.

Semi-automatic digital image control of nickel concentration in a Ni-P electroless acid bath using the hexaamminenickel blue complex

Nickel is the most employed metal in electroless coating baths, and its concentration must be continuously well controlled to obtain the desired coating qualities. Nowadays, automated systems for its control are used in the coating industry, but they are expensive and unaffordable for small companies. Therefore, the development of a simplest method that provides rapid results without requiring big amount of sample could be an improvement for these industries. In this study, a semiautomatic method based on digital image analysis (DIA) is presented. A smartphone is used as image acquisition device, and a colorimetric reaction is carried out in a microtitration plate between the Ni2+ present in the samples and ammonia to form a blue complex. A good linear correlation has been obtained between the S channel of the HSV color space and nickel concentration in the range between 2.0 and 5.7 g/L. All evaluated calibrations resulted in a limit of detection (LOD) and quantification (LOQ) below 0.44 g/L and 1.32 g/L respectively. A function developed in MATLAB automates the procedure for obtaining the nickel sample concentration from the acquired image. The function also recommends the necessary amount of nickel solution that must be added to recover the initial metal quantity. Precision and accuracy were evaluated using real samples which had been previously titrated with EDTA to assess nickel concentration. Relative standard deviations (RSD) lower that 2.2 % and relative errors (RE) lower than 2.4 % have been obtained. As a final step, the method has been applied to control a real bath in which 47 measurements were made. The developed automation enables the bath operator to monitor the metal concentration and add the necessary volume of reagents to maintain the optimum conditions, helping the coating industry to save time, reagents, sample, and money.

The Iodine/Iodide/Starch Supramolecular Complex

The nature of the blue color in the iodine–starch reaction (or, in most cases, iodine–iodide-starch reaction, i.e., I2 as well as I− are typically present) has for decades elicited debate. The intensity of the color suggests a clear charge-transfer nature of the band at ~600 nm, and there is consensus regarding the fact that the hydrophobic interior of the amylose helix is the location where iodine binds. Three types of possible sources of charge transfer have been proposed: (1) chains of neutral I2 molecules, (2) chains of poly-iodine anions (complicated by the complex speciation of the I2-I− mixture), or (3) mixtures of I2 molecules and iodide or polyiodide anions. An extended literature review of the topic is provided here. According to the most recent data, the best candidate for the “blue complex” is an I2-I5−-I2 unit, which is expected to occur in a repetitive manner inside the amylose helix.

Towards a genomic resolution of the Phengaris alcon species complex

AbstractTaxonomic entities below the species level often pose difficulties for conservation practice, especially when they are ecologically distinct from the nominal species. Genomic tools provide the opportunity to study and potentially resolve such cryptic diversity. The Alcon blue butterfly Phengaris alcon species complex is such a cryptic example, comprising different ecotypes or even subspecies, one of them is the high elevation taxon P. rebeli from the European Alps. We sequenced a first reference genome for Phengaris alcon. Furthermore, we generated whole genome resequence data for individuals of three Swiss ecotypes, i.e., the low elevation P. alcon, the mid elevation and high elevation alpine P. rebeli and integrated genomic data from across Europe to study the relationship among these ecotypes. At a European scale, our results suggest that for the P. alcon complex, biogeography and the evolutionary context of diversification is more multifaceted than previously suggested, falling in the range of more recent ecological speciation. In Switzerland, the three ecotypes were genetically isolated with only limited current gene flow between them. Past gene flow, however, could have given rise to the mid elevation ecotype. Our findings emphasise that high elevation P. rebeli in the Alps should be treated as a distinct species. Our study highlights how the availability of reference genome assemblies allows to address so far open taxonomic questions in conservation research and that broadscale studies are needed to understand the biogeographic history of apparent diversification.

A facile double moving redox boundary model for visual electrophoresis titration of ascorbic acid.

In this work, we proposed a double moving redox boundary (MROB) model to realize the colorless analyte electrophoresis titration (ET) by the two steps of the redox reaction. Single MROB has been proposed for the development of ET sensing (Analyst, 2013, 138, 1137. ACS Sensor, 2019, 4, 126.), and faces great challenges in detecting the analyte without color change during redox reaction. Herein, a novel model of double-MROB electrophoresis, including its mechanisms, equations, and procedures, was developed for titration by using ascorbic acid as a model analyte. The first MROB was created with ferric iron (Fe3+) and iodide ion (I-) in which Fe3+ was reduced as Fe2+ and I- was oxidized as molecular iodine (I2) used as an indicator of visible MROB due to blue starch-iodine complex. The second boundary was then formed between the molecular iodine and model analyte of ascorbic acid. Under given conditions, there was a quantitative relationship between velocity of MROB (VMROB(ii)) and ascorbic acid concentration (CVit C) in the double-MROB system (1/VMROB(ii)=0.6502CVit C+4.5165, and R=0.9939). The relevant relative standard deviation values of intraday and inter-day were less than ∼5.55% and ∼6.64%, respectively. Finally, the titration of ascorbic acid in chewable vitamin C tablets was performed by the developed method, the titration results agreed with those via the classic iodometric titration. All the results briefly demonstrated the validity of the double MROB model, in which Vit C was used as a model analyte. The developed method had potential use in quantitative analysis of redox-active species in biomedical samples.

Enhanced selective adsorption capacity of lead (II) from complex wastewater by aminopropyltriethoxysilane-functionalized biochar grafted on the MXene based on anion-synergism

The simultaneous elimination of dyes and metal ions from wastewater is essential for industrial wastewater treatment. In the current work, a novel adsorbent, aminopropyltriethoxysilane-functionalized biochar grafted on MXene (APTES/BC/MXene composite), was synthesized and utilized to increase the selectivity of the uptake of lead from a complex multi-metal solution based on anion-synergism. The surface area of the APTES/BC/MXene composite (164 m2/g) was higher as compared to the BC (90 m2/g), APTES (87 m2/g), and APTES/BC (151 m2/g). The outcomes of selective adsorption of metal ions were altered by the composite before (APTES = 52.98 mg/g, APTES/MXene = 58.65 mg/g, and APTES/BC = 313.86 mg/g) and after grafting aminopropyltriethoxysilane-functionalized biochar on the MXene (APTES/BC/MXene = 323.17 mg/g). In this investigation, the composite showed remarkable selectivity for the adsorption of lead. The adsorption capacity of composite for Pb2+ (323.17 mg/g) was superior compared to Cd (16.45 mg/g), Sr (10.99 mg/g), Zn (25.37 mg/g), Ni (7.82 mg/g, Ca (20.79 mg/g), and Ag (58.47 mg/g). Interestingly, the selective uptake of lead by the composite was enhanced from 446.85 to 1072.04 mg/g as coexisting methyl blue dosages increased from 0 to 100 mg/L at a pH value of 6.0. In the lead-methyl blue complex binary system, lead and methyl blue indicated synergistic phenomena, in which the existence of methyl molecules generated new unique sites for lead adsorption, while methyl blue uptake was also increased by the existence of lead. The experiment's findings demonstrate that the prepared APTES/BC/MXene exhibited excellent stability and regeneration capabilities (96.2% and 95.1% adsorption efficacy after 5th cycles for Pb2+ and MB respectively), suggesting it can be employed as a quick and efficient uptake adsorbent for the elimination of MB and Pb2+ in a single pollutant system. Hydrogen bonding, electrostatic interaction, synergistic penetration, and ion exchange processes were primarily involved in the uptake of lead and methyl blue. This investigation offers useful insights for the development of composite that indicate outstanding performance and easy recovery for the synergistic and simultaneous uptake of heavy metal ions and organic dyes. The results also reveal the remarkable enhancement of selective heavy metal uptake from complex wastewater by utilizing anion-bye interactions.

Dinitrogen reduction chemistry with scandium provides a complex with two side-on (N[double bond, length as m-dash]N)2- ligands bound to one metal: (C5Me5)Sc[(µ-η2:η2-N2)Sc(C5Me5)2]2.

Although there are few reduced dinitrogen complexes of scandium, this metal has revealed a new structural type in reductive dinitrogen chemistry by reduction of bis(pentamethylcyclopentadienyl) scandium halides under N2. Reduction of (Cp* = C5Me5) with potassium graphite (KC8) under dinitrogen generates the dark blue paramagnetic complex , 1. This end-on bridging (N[double bond, length as m-dash]N)2- complex is a diradical with a magnetic moment of 2.8µ B. Upon further reduction of 1 with KC8, the orange diamagnetic trimetallic complex , 2, is obtained. This complex has an unprecedented structure in which two side-on bridging (N[double bond, length as m-dash]N)2- ligands are bound to the central (Cp*Sc)2+ moiety. Complex 2 can also be obtained directly from reduction of or a mixture of and with KC8. The reaction of with KC8 in the presence of 18-crown-6 or 2.2.2-cryptand affords 2 along with small amounts of , 3, which is green at room temperature and purple at low temperature and displays a mixture of side-on and end-on bridging isomers in the crystal structure collected at -180 °C. Density functional theory (DFT) calculations are consistent with a triplet ground state for the end-on complex 1 and singlet ground states for the side-on complexes 2 and 3.

Study of Serum Magnesium, Potassium and Calcium in Acute Myocardial Infarction Patients

Introduction: A myocardial infarction happens when blood flow stops or decreases to the coronary arteries of the myocardial muscle, resulting in damage to the heart muscle. Magnesium is important electrolyte plays vital role in suppressing arrhythmias during myocardial ischemia and during reperfusion. Potassium is the most abundant cation of intracellular fluid. A significant correlation between hypokalemia and ventricular fibrillation is recorded. Calcium plays a vital role in myocardial muscle contraction. Aim: To study serum levels of magnesium, potassium and calcium in acute myocardial infarction patients. Material and methods: This was a prospective case control study conducted in Prathima Institute of medical sciences Nagunur, Karimnagar, Telangana state, India between January 2015 to December 2015. A total 50 acute myocardial infarction patients and 50 normal age and sex matched healthy controls selected for study. Serum magnesium estimated by colorimetric xylidyl blue complex method, serum potassium estimated by ion selective electrode method and serum calcium by OCPC method. Statistical analysis carried out using statistical software SPSS version 16 and p-value < 0.05 considered statistically significant. Results: Serum levels of magnesium, potassium and calcium were significantly decreased in acute myocardial infarction patients when compared healthy controls and is statistically significant (<0.05) Conclusion: The above study suggested decreased serum level of key elements such as magnesium, potassium and calcium in acute myocardial infarction patients when compared to healthy controls. Estimation and correction of these elements may play a pivotal role in management of patients with acute myocardial infarction

Phosphorus Analysis in Meat using UV-Vis Spectrophotometry with SnCl2 and Hydrazine Sulfate Reduction

<p>This study aimed to optimize phosphorus analysis in meat using a molybdenum blue reaction involving SnCl<sub>2</sub> and hydrazine sulfate as reducing agents to establish the most effective conditions for phosphorus detection. Meat, an essential source of nutrients like phosphorus, plays a vital role in human health, particularly bone and tooth strength. However, overconsumption of phosphorus can lead to health issues such as hyperphosphatemia, making regular monitoring of phosphorus levels in food necessary. The experiment used SnCl<sub>2</sub> and hydrazine sulfate under varying acidic conditions to produce a stable blue complex indicative of phosphorus presence. The complex exhibited maximum absorbance in the 689–729 nm wavelength range. Validation of the method showed high linearity with R<sup>2</sup> values of 0.9983 and 0.9984 for SnCl<sub>2</sub> and hydrazine sulfate, respectively. The molar absorptivity for SnCl<sub>2</sub> was 2.093 x 105 L mol<sup>-1</sup> cm<sup>-1</sup> and 7.92 x 104 L mol<sup>-1</sup> cm<sup>-1</sup> for hydrazine sulfate. Detection and quantification limits were established, and the %RSD values in each sample ranged from 1.08% to 1.93%, conforming to standard requirements. Upon analysis of meat samples, including duck, chicken, and beef, the phosphorus levels did not meet the Indonesian Nutritionist Association (PERSAGI) standards. This result emphasizes the need for regular phosphorus analysis in meat products to prevent health risks associated with excessive phosphorus intake, such as hyperphosphatemia.</p>

Tools to Simulate Resonance Raman Spectra for in-Situ Studies of Electron Transport Mediators and Bioelectrocatalysts

Raman spectroscopy is widely applied as an in-situ probe of electrochemical processes. When the excitation light is resonant with an electronic transition, the detected signal can be enhanced by more than 1,000-fold. Resonance Raman (RR) spectroscopy has broad application in the study of common organic electron transport mediators (i.e., viologens, phenazines, photosynthetic pigments) and active sites of redox proteins (i.e., laccases, peroxidases, flavin-containing enzymes). To support investigations of bioelectrocatalytic membranes, we have been adapting RR spectroscopy to gain insights into the properties of immobilized redox mediators and biocatalyst active sites.1,2 Computational methods can be useful for guiding spectral interpretation. This poster reports on applications of recently advanced time-dependent density functional theory (TDDFT) codes that enable the simulation of RR spectra for small electron transport mediators (e.g., methyl viologen radical anion) and redox protein active site models (e.g., laccase T1 site mimics). The ORCA program suite3 was adapted. A series of Cu-centered compounds that model the T1 active site in laccases was studied along with the methyl viologen radical cation. The T1 site in laccases facilitates direct electron transport to an electrode and is a target for in-situ RR measurements. The reported work demonstrates careful selection of the functional (B3-LYP versus the long-range corrected hybrid exchange functional, ωB97X-D3) results in TDDFT-calculated electronic absorption and RR spectra that have features in excellent agreement with experiment. The results provide a foundation to build from in advancing models of small redox mediators and laccase catalytic active sites in support of sustainable technologies. Ozuguzel, U.; Aquino, A.J.A.; Nieman, R.; Minteer, S.D.; Korzeniewski, C. “Calculation of Resonance Raman Spectra and Excited State Properties for Blue Copper Protein Model Complexes” ACS Sustainable Chem. Eng. 2022, 10, 14614. Xu, J.; Koh, M.; Minteer, S. D.; Korzeniewski, C. “In Situ Confocal Raman Microscopy of Redox Polymer Films on Bulk Electrode Supports” ACS Measurement Science Au 2023 (DOI: 10.1021/acsmeasuresciau.2c00064). Neese, F.; Wennmohs, F.; Becker, U.; Riplinger, C. “ORCA Quantum Chemistry Program Package” J. Chem. Phys. 2020, 152, 224108.