Electrochemical oxidation and determination of ceftriaxone on a glassy carbon and carbon-nanotube-modified glassy carbon electrodes

Pharmacokinetic Interpretation of Applying Local Drug Delivery System for the Treatment of Deep Surgical Site Infection in the Spine

Surgical site infections (SSIs) after spinal surgery present significant challenges, including poor antibiotic penetration and biofilm formation on implants, leading to frequent treatment failures. Polymethylmethacrylate (PMMA) is widely used for localized drug delivery in bone infections, yet quantifying individual drug release kinetics is often impractical. This retrospective study analyzed 23 cases of deep SSIs (DSSIs) following spinal surgery treated with antibiotic-loaded PMMA. A mathematical model estimated personalized drug release kinetics from PMMA, considering disease types, pathogens, and various antibiotics. The study found that vancomycin (VAN), ceftriaxone (CRO), and ceftazidime (CAZ) reached peak concentrations of 15.43%, 15.42%, and 15.41%, respectively, within the first two days, which was followed by a lag phase (4.91-4.92%) on days 2-3. On days 5-7, concentrations stabilized, with CRO at 3.22% and CAZ/VAN between 3.63% and 3.65%, averaging 75.4 µg/cm2. Key factors influencing release kinetics include solubility, diffusivity, porosity, tortuosity, and bead diameter. Notably, a patient with a low glomerular filtration rate (ASA IV) was successfully treated with a shortened 9-day intravenous VAN regimen, avoiding systemic complications. This study affirms the effectiveness of local drug delivery systems (DDS) in treating DSSIs and underscores the value of mathematical modeling in determining drug release kinetics. Further research is essential to optimize release rates and durations and to mitigate risks of burst release and tissue toxicity.

High sensitivity, low-cost, and disposability: A novel screen-printed electrode developed for direct electrochemical detection of the antibiotic ceftriaxone

This study describes the development of a novel disposable and low-cost electrochemical platform for detecting the antibiotic ceftriaxone. The screen-printed electrode has been modified with a novel hybrid nanostructure containing silicon oxide (SiO2), zirconium oxide (ZrO2), and nitrogen-doped carbon quantum dots (Cdot-N). Different techniques like Fourier-transform infrared spectroscopy, Raman spectroscopy, and transmission electron microscopy characterized the hybrid nanostructure used in the sensor surface modifier material. The hybrid nanostructure showed an excellent synergistic effect that contributed to the oxidation reaction of ceftriaxone. The screen-printed electrode modified with SiO2/ZrO2/Cdot-N nanostructure presented high sensitivity with a detection limit of 0.2 nmol L-1 in the linear range of 0.0078-40.02 μmol L-1. The measurements have been performed by square wave voltammetry technique. Studies on real samples of synthetic urine, urine, and tap water showed 95%-105% recovery without applying any sample pretreatment. The sensor demonstrated excellent selectivity in the antibiotic ceftriaxone determination in the presence of possible interferences cationic, Na+, K+, Ca2+, Mg2+, Cu2+, Pb2+, Mn2+, Zn2+, Co2+, and biological, glucose, caffeine, uric acid, and ascorbic acid. The developed sensor becomes a selective, sensitive, and applicable tool in determining the antibiotic ceftriaxone.

Mechanism and efficiency research of P- and N-codoped graphene for enhanced paracetamol electrocatalytic degradation

Electrocatalytic oxidation is an effective technology for treatment of refractory organic pollutants, and its performance strongly depends on anode materials. Among all anode materials, graphene (GN) owns the advantages of high stability and lack of secondary pollution. The catalytic performance of GN can be further improved through heteroatom doping. Here, P/N-codoped graphene (PN-GN) materials were optimized and used as an anode material for 4-acetamidophenol (APAP) electrocatalytic degradation. Result indicated that PN-GN had lower internal resistance, larger specific surface area, and higher electrochemical activity than single-doped graphene materials. The catalytic activity of GN was greatly improved by P/N codoping. When PN-GN (P8.4%-N7.6%-500 °C) was used as catalyst (current of 20 mA, initial pH of 7, reaction time of 60 min), the degradation efficiency of APAP reached 98.2% ± 1.8%, which was 17.9% ± 3.6% higher than P-codoped graphene (P-GN), 14.7% ± 4.6% higher than N-codoped graphene (N-GN), and 54.0% ± 5.2% higher than GN. After 180 min of reaction, the degradation efficiency of total organic carbon (TOC) was 78.5%. The reaction conditions were optimized and the degradation pathway of APAP was estimated to elucidate the catalytic mechanism. The main active substances generated in the system were identified as active chlorine and O₂^•-.

Development and Validation of a Simple Procedure for the Kinetic Spectrophotometric Quantitative Determination of Ceftriaxone Using Potassium Caroate

A simple procedure for the quantitative determination of the Ceftriaxone pure substance by the spectrophotometric method in its kinetic modification using Caro’s acid has been developed and validated. The scheme of the chemical transformation of Ceftriaxone with the reaction of potassium caroate has been proposed. The appearance of a new wave gives the possibility of developing a new procedure for the quantitative determination of Ceftriaxone. The obtained results of accuracy and precision are as follows: RSD = 1.63-2.25 %, δ = 0.33-0.96 %. LOD = 0.1 µg/mL, LOQ = 0.33 µg/mL.

Development of a Composite of Polypyrrole-Coated Carbon Nanotubes as a Sonosensitizer for Treatment of Melanoma Cancer Under Multi-Step Ultrasound Irradiation

Sonodynamic therapy (SDT) has established a novel route for treating solid cancers. Low-intensity ultrasound irradiation accompanied by a sonosensitizer has revealed remarkable advantages for cancer therapy such as targeted uptake, access to deeper tumors, insignificant side effects and invasiveness, compared with other therapeutic methods. In this study, we scrutinized synthesis and characterization of a polypyrrole-coated multi-walled carbon nanotubes composite (PPy@MWCNTs). PPy@MWCNTs can absorb ultrasound irradiation by both of its components, and it was introduced as a new sonosensitizer. The composite was characterized by field emission scanning electron microscopy (FESEM), and its ability to temperature elevation was explored. FESEM images revealed that PPy@MWCNTs comprised nanotubes of 36.3 ± 5.1 nm in diameter with up to several micrometer in length. Ultrasound irradiation at 1 MHz and 1.0 W cm^-2 for 60 s in four steps led to an efficient SDT in vitro (16.3 ± 2.8°C temperature increment for 250 μg mL^-1 of PPy@MWCNTs), in C540 (B16/F10) cell line and a melanoma tumor model in male balb/c mice. In vitro examinations revealed that PPy@MWCNTs represented a concentration-dependent cytotoxicity on multi-step ultrasound irradiation (a cell viability of 8.9% for 250 μg mL^-1 of PPy@MWCNTs). Histologic analyses and tumor volume decrement after 10 d revealed detrimental SDT effects of PPy@MWCNTs on tumors (75% necrosis and 50% decrement in tumor volume). Thermal effects and reactive oxygen species generation were the reasons of the working function of PPy@MWCNTs in SDT.

Recent Electrochemical Assays on Cephalosporins

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Antibiotics are an important class among drugs because they are a significant agent to deal with infections. Cephalosporins are a very important group of antibiotics in the β-lactam class. The cephalosporins are semisynthetic antibiotics derived from products of the fungus Cephalosporium. Cephalosporins are classified as first, second, third, fourth, and advanced generation, based largely on their antibacterial spectrum and stability to β-lactamases. Electrochemical methods have been used for the determination of cephalosporin just as used in the determination of many antibiotic drugs. Electroanalytical methods present generally high sensitivity, low cost, low requirements, ease of preparation of the samples in a very short time, and a short analysis time. The most commonly used types are cyclic voltammetry, differential pulse voltammetry, square wave voltammetry and linear sweep voltammetry. The aim of this review is to evaluate the advantages and uses of electroanalytical methods used in the determination of cephalosporins. In addition, current applications of the methods to the pharmaceutical analysis of cephalosporins will also be summarized in a table.

Highly Efficient Gold Nano-Flower Optical Biosensor Doped in a Sol-Gel/PEG Matrix for the Determination of a Calcitonin Biomarker in Different Serum Samples

We developed a novel, simple, sensitive, accurate, and precise method for the determination of calcitonin in different serum samples with medullar thyroid carcinoma. The designed flower-like thin film gold nanoparticles doped in a sol-gel/polyethylene glycol mold are used as an optical biosensor for the efficient determination of calcitonin. The sensor was characterized by transmission electron microscopy, scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray microanalysis, and Fourier-transform infrared spectroscopy. The efficiency of the considered bio-sensor is done using the quencher calcitonin of the emission band at 360 nm of biomarker obtained at λ_ex = 333 nm in acetonitrile solvent. The sensing mechanism was based on fluorescence resonance energy transfer. The remarkable quenching of the fluorescence intensity at 360 nm of optical sensor by various concentrations of calcitonin was successfully used as an optical biosensor for the assessment of calcitonin for different serum samples of patients with medullar thyroid carcinoma. The calibration plot was prepared for the concentration range 0.01-1000 pg/mL of calcitonin with a correlation coefficient of 0.99 and a detection limit of 0.707 pg/mL. The suggested method augments the sensitivity of calcitonin as a useful biomarker for the early diagnosis of medullar thyroid carcinoma. This method is considered as a gateway for the construction of a new prototype for the follow-up of thyroid cancer in the spinal cord during and after treatment.

State of the Art in Alcohol Sensing with 2D Materials

Since the discovery of graphene, the star among new materials, there has been a surge of attention focused on the monatomic and monomolecular sheets which can be obtained by exfoliation of layered compounds. Such materials are known as two-dimensional (2D) materials and offer enormous versatility and potential. The ultimate single atom, or molecule, thickness of the 2D materials sheets provides the highest surface to weight ratio of all the nanomaterials, which opens the door to the design of more sensitive and reliable chemical sensors. The variety of properties and the possibility of tuning the chemical and surface properties of the 2D materials increase their potential as selective sensors, targeting chemical species that were previously difficult to detect. The planar structure and the mechanical flexibility of the sheets allow new sensor designs and put 2D materials at the forefront of all the candidates for wearable applications. When developing sensors for alcohol, the response time is an essential factor for many industrial and forensic applications, particularly when it comes to hand-held devices. Here, we review recent developments in the applications of 2D materials in sensing alcohols along with a study on parameters that affect the sensing capabilities. The review also discusses the strategies used to develop the sensor along with their mechanisms of sensing and provides a critique of the current limitations of 2D materials-based alcohol sensors and an outlook for the future research required to overcome the challenges.

Highly sensitive detection of Ceftriaxone in water, food, pharmaceutical and biological samples based on gold nanoparticles in aqueous and micellar media

A colorimetric assay with excellent sensitivity is reported to detect Ceftriaxone in aqueous and micellar solutions. Ceftriaxone could induce the aggregation of gold nanoparticles through hydrogen-bonding interaction and electrostatic attraction. As a result of aggregation, the surface plasmon resonance band around 520 nm decreases and a new band appears at 620 nm. The effect of surfactants was investigated on the aggregation. The band around 620 nm is shifted to around 685 nm in Triton X-100 micellar media and that is seen color conversion from red to deep blue which is clearly detectable by the naked eye. The results were improved in Triton X-100 micellar media as compared to aqueous media so that the lowest measured concentration and detection limit in micellar media have decreased 10 and 8 times, respectively. Triton X-100 showed strong effect on the stabilization of the solutions. The method has been successfully applied for the analysis of various real samples.

Electrooxidation of sulfanilamide and its voltammetric determination in pharmaceutical formulation, human urine and serum on glassy carbon electrode

For the first time, sulfanilamide (SFD) was determined in otologic solution, human urine and serum by electroanalytical techniques on glassy carbon electrode (GCE). The cyclic voltammetry (CV) experiments showed an irreversible oxidation peak at +1.06 V in 0.1 mol/L BRBS (pH = 2.0) at 50 mV/s. Different voltammetric scan rates (from 10 to 250 mV/s) suggested that the oxidation of SFD on the GCE was a diffusion-controlled process. Square-wave voltammetry (SWV) method under optimized conditions showed a linear response to SFD from 5.0 to 74.7 μmol/L (R = 0.999) with detection and quantification limits of 0.92 and 3.10 μmol/L, respectively. The developed SWV method showed better results for detection limit and linear range than the chronoamperometry method. It has been successfully applied to determine SFD concentration in pharmaceutical formulation, human urine and serum samples with recovery close to 100%.

An ultrasensitive and selective method for the determination of Ceftriaxone using cysteine capped cadmium sulfide fluorescence quenched quantum dots as fluorescence probes

In this paper, l-cysteine (Cys) coated CdS quantum dots (QDs) have been prepared, which have excellent water-solubility and are highly stable in aqueous solution. These QDs is proposed as sensitizers for the determination of Ceftriaxone. The quantum dot nanoparticles were structurally and optically characterized by Ultra Violet-Visible absorption Spectroscopy (UV-vis absorption spectroscopy), Fourier transform infrared spectroscopy (FT-IR spectra) and photoluminescence (PL) emission spectroscopy. High resolution transmission electron microscopy (HRTEM) confirms that the Cys-CdS QDs have a spherical structure with good crystallinity. Therefore, a new simple and selective PL analysis system was developed for the determination of Ceftriaxone (CFX). Under the optimum conditions, The response of l-Cys capped CdS QDs as the probe was linearly proportional to the concentration of Ceftriaxone ions in the range of 1.6×10(-9)-1.1×10(-3)M with a correlation coefficient (R2) of 0.9902. The limit of detection of this system was found to be 1.3nM. This method is simple, sensitive and low cost.

Nanostructured materials in electroanalysis of pharmaceuticals

Basic strategies and recent developments for the enhancement of the sensory performance of nanostructures in the electroanalysis of pharmaceuticals are reviewed. A discussion of the properties of nanostructures and their application as modified electrodes for drug assays is presented. The electrocatalytic effect of nanostructured materials and their application in determining low levels of drugs in pharmaceutical forms and biofluids are discussed.

Sensitivity and selectivity determination of bisphenol A using SWCNT-CD conjugate modified glassy carbon electrode

In this study, we demonstrated a highly sensitive electrochemical sensor for the determination of bisphenol A (BPA) in aqueous solution by using single-walled carbon nanotubes (SWCNTs)/β-cyclodextrin (β-CD) conjugate (SWCNT-CD) modified glassy carbon electrode (GCE). The cyclic voltammetry results show that the modified GCE exhibits strong catalytic activity toward the oxidation of BPA with a well-defined cyclic voltammetric peak at 0.543 V. The response current exhibits a linear range between 10.8 nM and 18.5 μM with a high sensitivity (1256 μA mM(-1)). The detection limit of BPA is 1.0 nM (S/N=3). The enhanced performance of the fabricated sensor can be attributed to the combination of the excellent electrocatalytic properties of SWCNTs and the molecular recognition ability of β-CD. The sensor was successfully applied to determine BPA leached from real plastic samples with good recovery, ranging from 95% to 103%.

Glassy carbon electrode modified with multi-walled carbon nanotubes sensor for the quantification of antihistamine drug pheniramine in solubilized systems

A sensitive electroanalytical method for quantification of pheniramine in pharmaceutical formulation has been investigated on the basis of the enhanced electrochemical response at glassy carbon electrode modified with multi-walled carbon nanotubes in the presence of sodium lauryl sulfate. The experimental results suggest that the pheniramine in anionic surfactant solution exhibits electrocatalytic effect resulting in a marked enhancement of the peak current response. Peak current response is linearly dependent on the concentration of pheniramine in the range 200–1500 μg/mL with correlation coefficient 0.9987. The limit of detection is 58.31 μg/mL. The modified electrode shows good sensitivity and repeatability.

Electrocatalytic oxidation and determination of antibiotic in pharmaceutical samples on a nanostructure

A copper hexacyanoferrate nanostructure was prepared on the surface of a disposable pencil graphite electrode. The copper hexacyanoferrate nanostructures showed a pair of symmetric voltammetric peaks at 0.67 V/SCE. An electrochemical comparative characterization between copper hexacyanoferrate nano and bulk structures was presented. The transfer coefficient (α) and apparent charge rate constant (Ks) were evaluated for each of copper hexacyanoferrate nano and bulk structures. The resulting electrode exhibits an excellent electrocatalytic activity for the oxidation of ceftriaxone sodium. Cyclic voltammetry and chronoamperometry were employed to characterize the response to ceftriaxone sodium that changes linearly in the concentration range from 2 to 72 μM, with a detection limit of 0.54 μM (at a signal to noise ratio of 3). Typical features of the sensor include low cost, simple preparation, fast response, good stability, selectivity, and reproducibility. It was applied to the determination of ceftriaxone sodium in pharmaceutical samples. All results obtained were compared to the recommended procedure by British Pharmacopeia.