Determination of uric acid in serum using an optical sensor based on binuclear Pd(II) 2-pyrazinecarboxamide-bipyridine doped in a sol gel matrix

A New approach for simultaneous detection and photocatalytic degradation of imidacloprid and dinotefuran in water using terbium-based fluorometry and mixed-phase TiO2

This study explores a novel method for detecting neonicotinoid insecticides, imidacloprid (IMD) and dinotefuran (DNT), in water using terbium (Tb3+) ions photo probe. The optimal excitation and emission wavelengths for Tb3+ luminescence were identified at 310 nm and 545 nm, respectively. The influence of pH and solvent on Tb-complex fluorescence was investigated. Results indicate a significant enhancement of luminescence intensity at pH 6 for IMD in DMF and pH 7.0 for DNT in DMSO. The fluorescence intensity exhibited a linear relationship with IMD and DNT concentrations ranging from 0.1 to 20 µg/mL (R2 > 0.99). Limits of quantitation (LOQ) were determined as 0.1 µg/mL for IMD and 0.05 µg/mL for DNT. This newly developed photo probe demonstrates the potential for monitoring photolysis and photocatalytic degradation of these neonicotinoids using TiO2 as a catalyst under controlled photoreactor conditions. The method offers a promising alternative for rapidly and sensitively detecting these prevalent insecticides in water samples.

Polymer-Based Terbium Complex as a Fluorescent Probe for Cancer Antigen 125 Detection: A Promising Tool for Early Diagnosis of Ovarian Cancer

A novel photoprobe, Tb-acetylacetone (Tb-ACAC) doped within a modified epoxy cellulose polymer immobilized with CA-125 monoclonal antibody, offers an accurate and highly selective method for early ovarian cancer (OC) diagnosis by detecting cancer antigen 125 (CA-125) in serum samples. This approach leverages quenching of the Tb-ACAC luminescence upon binding to CA-125. Characterization of the photoprobe film through UV-vis and fluorescence measurements confirmed the presence of Tb-ACAC within the polymer matrix. In aqueous solution (pH 6.8, λex = 365 nm), the characteristic emission band of Tb-ACAC at λem = 546.2 nm exhibited significant quenching upon CA-125 binding. This quenching effect enabled the sensitive and specific detection of CA-125 in diverse serum samples from OC patients, demonstrating the applicability, simplicity, and effectiveness of this novel approach.

Novel sensor for the determination of CA 15-3 in serum of breast cancer patients based on Fe-gallic acid complex doped in modified cellulose polymer thin films

Fe-gallic acid MOF embedded in an epoxy methyl cellulose polymer (CMC) thin film was synthesized and characterized by different micro-analytical tools such as: FE-SEM/EDX, XPS analysis, XRD analysis, FT-IR, and fluorescence spectroscopy. Fe-gallic acid MOF doped in a stable CMC polymer thin film is used as a novel sensor to identify CA 15-3 in the sera of patients suffering breast malignancy. The presence of appropriate functional groups in aqueous CA 15-3 solutions enables it to interact with the Fe-gallic acid MOF embedded in the thin film. The Fe-gallic acid MOF was found to absorb energy at 350 nm (λex) and emits radiation at 439 nm which was specifically quenched in the presence of CA 15-3 over a working concentration range of 0.05-570 U mL-1. In contrast to other CA 15-3 detection methods which suffered from electronic noise, interference and slowness, the Fe-gallic acid MOF proved its sensitivity as an economic, stable and reliable probe for the detection and determination of CA 15-3 in patients' serum samples with a detection limit of 0.01 U mL-1 at pH 7.2.

Highly selective optical sensor N/S-doped carbon quantum dots (CQDs) for the assessment of human chorionic gonadotropin β-hCG in the serum of breast and prostate cancer patients

A low-cost, accurate, and highly selective method was used for the assessment of the human chorionic gonadotropin β-hCG in the serum of breast and prostate cancer patients. This method is based on enhancing the intensity of luminescence displayed by the optical sensor N/S-doped carbon dots (CQDs) upon adding different concentrations of β-hCG. The luminescent optical sensor was synthesized and characterized through absorption and emission and is tailored to present blue luminescence at λem = 345 nm and λex = 288 nm at pH 7.8 in DMSO. The enhancement of the luminescence intensity of the N/S-doped CQDs, especially, the characteristic band at λem = 345 nm, is typically used for determining β-hCG in different serum samples. The dynamic range is 1.35-22.95 mU mL-1, and the limit of detection (LOD) and quantitation limit of detection (LOQ) are 0.235 and 0.670 mU mL-1, respectively. This method was practical, simple, and relatively free from interference effect. It was successfully applied to measure PCT in the samples of human serum, and from this method, we can assess some biomarkers of cancer-related diseases in human body.

A highly selective optical sensor Eu-BINAM for assessment of high sensitivity cardiac troponin tumor marker in serum of cancer patients

A novel, easy, touchy and selective spectrofluorimetric technique has been successfully applied for sensitive determination of High Sensitivity Cardiac Troponin (TNHS I) in the serum samples of patients suffering malignant tumors through the usage of optical sensor Eu^3+-BINAM complex. The technique is primarily based on quenching of the Eu³⁺-BINAM complex's luminescence intensity upon introducing various concentrations of High Sensitivity Cardiac Troponin (TNHS I). The synthesis and characterization of the optical sensor was performed via absorption and emission. The sensor was also adapted to offer excitation at 394 nm in acetonitrile at pH 7.5. Concentration of High Sensitivity Cardiac Troponin (TNHS I) in serum samples was found to be proportional to the luminescence intensity quenching of the Eu³⁺-BINAM complex, most prominently at λ_em = 618 nm. The limit of the dynamic range is 4.26 × 10^-4 to 2 ng/mL. The limit of detection and quantitation were calculated to be 1.35 and 4.10 ng/mL, respectively. The suggested analytical approach proved its applicability, simplicity and comparatively interference- free. The technique was effectively recruited to quantify High Sensitivity Cardiac Troponin (TNHS I) in human serum samples. The proposed technique could be further extended to evaluate some biomarkers associated with malignancy related diseases in human.

Abdel-Sattar N, Mohamed EH, Mahmoud SA, Attia MS. Development and validation of molnupiravir assessment in bulk powder and pharmaceutical formulation by the RP-HPLC-UV method

An accurate, sensitive and selective RP-HPLC-UV method has been established for the estimation of Molnupiravir (MOL) in pure bulk powder and pharmaceutical formulation. Separation was achieved on an Inertsil C₁₈ column (150.0 mm × 4.6 mm, 5.0 μm), using a mobile phase of 20 mM phosphate buffer pH 2.5 : acetonitrile (80 : 20, v/v%) in isocratic mode with a flow rate of 1.0 mL min^-1. The λ _max of MOL prepared in the chosen diluent (ethanol : water in equal proportions) was found to be 230.0 nm. The constructed calibration curve was found to be linear in the concentration range of 0.2-80.0 μg mL^-1. The recovery% of MOL using the proposed method was 100.29%. The limit of detection (LOD) and limit of quantification (LOQ) were 0.04 μg mL^-1 and 0.12 μg mL^-1, respectively. No significant interference was detected in the presence of the common pharmaceutical formulation excipients. The method was validated following the ICH recommendations. All the obtained results were statistically compared with those using reported methods and there were no significant differences. The method developed in this work was successfully employed for the assessment of MOL in bulk powder and pharmaceutical formulation.

Synthesis and characterization of new 1,3,4-thiadiazole derivatives: study of their antibacterial activity and CT-DNA binding

1,3,4-Thiadiazole molecules (1-4) were synthesized by the reaction of phenylthiosemicarbazide and methoxy cinnamic acid molecules in the presence of phosphorus oxychloride, and characterized with UV, FT-IR, ¹³C-NMR, and ¹H-NMR methods. DFT calculations (b3lyp/6-311++G(d,p)) were performed to investigate the structures' geometry and physiochemical properties. Their antibacterial activity was screened for various bacteria strains such as Enterobacter aerogenes, Escherichia coli ATCC 13048, Salmonella kentucky, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus and Gram positive such as Staphylococcus aureus ATCC 25923, Listeria monocytogenes ATCC 7644, Enterococcus faecium, Enterococcus durans, Staphylococcus aureus ATCC, Serratia marcescens, Staphylococcus hominis, Staphylococcus epidermidis, alfa Streptococcus haemolyticus, Enterococcus faecium and found to have an inhibitory effect on Klebsiella pneumoniae and Staphylococcus hominis, while molecules 1, 3 and 4 had an inhibitory effect on Staphylococcus epidermidis and alpha Streptococcus haemolyticus. The experimental results were supported by the docking study using the Kinase ThiM from Klebsiella pneumoniae. All the investigated compounds showed an inhibitory effect for the Staphylococcus epidermidis protein. In addition, the mechanism of the 1-4 molecule interaction with calf thymus-DNA (CT-DNA) was investigated by UV-vis spectroscopic methods.

Novel Optical Biosensor Based on a Nano-Gold Coated by Schiff Base Doped in Sol/Gel Matrix for Sensitive Screening of Oncomarker CA-125

The urge for sensitive, facile, minimally invasive, and fast detection method of CA-125, a significant and crucial biomarker in ovarian malignancy, is currently substantial. This paper describes the detailed construction and characterization of a newly designed optical nano-biosensor to detect CA-125 accurately and sensitively. The fabricated sensor consists of a nano-gold thin film doped into a matrix of sol-gel, exhibiting a centered fluorescence band at 423 nm when excited at 340 nm. The quantification of CA-125 relies on its quenching ability of this fluorescence signal. The sensor was challenged to evaluate its sensitivity and specificity in detecting CA-125 present in samples collected from ovarian cancer diagnosed patients and compared to samples from healthy women as a control. Our findings revealed that the developed biosensor had a sensitivity of 97.35% and a specificity of 94.29%. Additionally, a wide linearity range over 2.0-127.0 U mL-1 for CA-125 was achieved with a detection limit of 1.45 U mL-1. Furthermore, the sensor could successfully discriminate samples between healthy and diseased people, which demonstrates its suitability in CA-125 assessment.

PDMS Based Hybrid Sol-Gel Materials for Sensing Applications in Alkaline Environments: Synthesis and Characterization

Nowadays, concrete degradation is a major problem in the civil engineering field. Concrete carbonation, one of the main sources of structures' degradation, causes concrete's pH to decrease; hence, enabling the necessary conditions for corrosion reinforcement. An accurate, non-destructive sensor able to monitor the pH decrease resistant to concrete conditions is envisaged by many researchers. Optical fibre sensors (OFS) are generally used for concrete applications due to their high sensitivity and resistance to external interferences. Organic-inorganic hybrid (OIH) films, for potential functionalization of OFS to be applied in concrete structures, were developed. Polydimethylsiloxane (PDMS) based sol-gel materials were synthesized by the formation of an amino alcohol precursor followed by hydrolysis and condensation. Different ratios between PDMS and (3-aminopropyl)triethoxysilane (3-APTES) were studied. The synthesized OIH films were characterized by Fourier-transformed infrared spectroscopy (FTIR), UV-Vis spectroscopy, electrochemical impedance spectroscopy (EIS) and thermogravimetric analysis (TGA). The OIH films were doped with phenolphthalein (Phph), a pH indicator, and were characterized by UV-Vis and EIS. FTIR characterization showed that the reaction between both precursors, the hydrolysis and the condensation reactions occurred successfully. UV-Vis characterization confirmed the presence of Phph embedded in the OIH matrices. Dielectric and thermal properties of the materials showed promising properties for application in contact with a high alkaline environment.