Magnetic Nanoparticles for Antibiotics Detection

Widespread use of antibiotics has led to pollution of waterways, potentially creating resistance among freshwater bacterial communities. Microorganisms resistant to commonly prescribed antibiotics (superbug) have dramatically increased over the last decades. The presence of antibiotics in waters, in food and beverages in both their un-metabolized and metabolized forms are of interest for humans. This is due to daily exposure in small quantities, that, when accumulated, could lead to development of drug resistance to antibiotics, or multiply the risk of allergic reaction. Conventional analytical methods used to quantify antibiotics are relatively expensive and generally require long analysis time associated with the difficulties to perform field analyses. In this context, electrochemical and optical based sensing devices are of interest, offering great potentials for a broad range of analytical applications. This review will focus on the application of magnetic nanoparticles in the design of different analytical methods, mainly sensors, used for the detection of antibiotics in different matrices (human fluids, the environmental, food and beverages samples)

Methylene Blue and Proflavine as Intraarterial Marker for Functional Perforazome—Comparative Study

Methylene blue (MB) is both a dye and a medicine known and used for a long time including as lymphatic tracer in melanoma and breast cancer for revealing sentinel lymph nodes. Proflavine (PRO) is an acriflavine dye, used as bacteriostatic disinfectant against many gram-positive bacteria that was also successfully applied to evaluate morphopathological changes in tissues. This study was performed on a group of twenty-eight Wistar rats and had as its main objective the in vivo evaluation of the use of MB and PRO as perforator tracers. The two dyes proved to be effective functional perforasome tracers with medium inflammatory infiltrate in the skin of the island perforator flap which heals perfectly at 14 days with complete absence of the inflammatory reaction. At the same injected amount, PRO seems to determine a greater inflammatory reaction compared with MB, but in smaller concentration, the inflammatory response is absent in the case of PRO. In conclusion, both substances tested within this in vivo study are good functional perforasome tracers, but PRO has the advantage of the absence of inflammatory reaction when using lower concentrations, while preserving unalerted its efficiency as tracer

NEW MODIFIED ELECTRODES WITH HRP IMMOBILIZED IN POLYMERIC FILMS FOR PARACETAMOL ANALYSIS

Abstract In order to establish the configurations of biosensors that are able to detect paracetamol in various matrices, it was studied the behaviour of some modified electrodes with an electroconductive polymeric film. Polypyrrole films deposition on glassy carbon and screen-printed electrodes was developped by several methods. The electroanalytical characterization of the deposited films was performed by chronoamperometry in the presence of an enzyme immobilized into the polymeric films. Chronoamperometric study performed with glassy carbon and planar electrodes based on graphite, modified with horseradish peroxidase embedded in polypyrrole films, proved the existence of interactions between the immobilized enzyme and the electroactive species of paracetamol (N-acetyl-p-benzo-quinone imine-NAPQI), enzymatically generated in the presence of hydrogen peroxide. Rezumat În vederea elaborării unor biosenzori capabili să detecteze paracetamolul din diferite matrici a fost studiat comportamentul electrozilor modificați cu filme electroconductoare de polipirol. Depunerea filmelor de polipirol pe suprafața electrozilor de carbon vitros și electrozilor planari imprimați a fost realizată prin mai multe metode. Caracterizarea electroanalitică a filmelor depuse a fost realizată prin cronoamperometrie, în prezența enzimei imobilizate la nivelul filmelor polimerice. Studiile de cronoamperometrie efectuate pe ambele tipuri de electrozi modificați cu peroxidaza din hrean, incorporată în filmul de polipirol, au demonstrat existența intercțiunilor între enzima imobilizată și speciile electroactive ale paracetamolului (Nacetil-p-benzo-chinon imina-NAPQI), generate enzimatic în prezența peroxidului de hidrogen

An Overview of Healthcare Associated Infections and Their Detection Methods Caused by Pathogen Bacteria in Romania and Europe

Healthcare-associated infections can occur in different care units and can affect both patients and healthcare professionals. Bacteria represent the most common cause of nosocomial infections and, due to the excessive and irrational use of antibiotics, resistant organisms have appeared. The most important healthcare-associated infections are central line-associated bloodstream infections, catheter-associated urinary tract infections, surgical site, soft tissue infections, ventilator-associated pneumonia, hospital acquired pneumonia, and Clostridioides difficile colitis. In Europe, some hospitalized patients develop nosocomial infections that lead to increased costs and prolonged hospitalizations. Healthcare-associated infection prevalence in developed countries is lower than in low-income and middle-income countries such as Romania, an Eastern European country, where several factors contribute to the occurrence of many nosocomial infections, but official data show a low reporting rate. For the rapid identification of bacteria that can cause these infections, fast, sensitive, and specific methods are needed, and they should be cost-effective. Therefore, this review focuses on the current situation regarding healthcare-associated infections in Europe and Romania, with discussions regarding the causes and possible solutions. As a possible weapon in the fight against the healthcare-associated infections, the diagnosis methods and tests used to determine the bacteria involved in healthcare-associated infections are evaluated

A Nanocomposite Based on Reduced Graphene and Gold Nanoparticles for Highly Sensitive Electrochemical Detection of <i>Pseudomonas aeruginosa</i> through Its Virulence Factors

Pyoverdine is a fluorescent siderophore produced by Pseudomonas aeruginosa that can be considered as a detectable marker in nosocomial infections. The presence of pyoverdine in water can be directly linked to the presence of the P. aeruginosa, thus being a nontoxic and low-cost marker for the detection of biological contamination. A novel platform was developed and applied for the electrochemical selective and sensitive detection of pyoverdine, based on a graphene/graphite-modified screen-printed electrode (SPE) that was electrochemically reduced and decorated with gold nanoparticles (NPs). The optimized sensor presenting higher sensitivity towards pyoverdine was successfully applied for its detection in real samples (serum, saliva, and tap water), in the presence of various interfering species. The excellent analytical performances underline the premises for an early diagnosis kit of bacterial infections based on electrochemical sensors

Electrochemical Peptide-Based Sensors for Foodborne Pathogens Detection

Food safety and quality control pose serious issues to food industry and public health domains, in general, with direct effects on consumers. Any physical, chemical, or biological unexpected or unidentified food constituent may exhibit harmful effects on people and animals from mild to severe reactions. According to the World Health Organization (WHO), unsafe foodstuffs are especially dangerous for infants, young children, elderly, and chronic patients. It is imperative to continuously develop new technologies to detect foodborne pathogens and contaminants in order to aid the strengthening of healthcare and economic systems. In recent years, peptide-based sensors gained much attention in the field of food research as an alternative to immuno-, apta-, or DNA-based sensors. This review presents an overview of the electrochemical biosensors using peptides as molecular bio-recognition elements published mainly in the last decade, highlighting their possible application for rapid, non-destructive, and in situ analysis of food samples. Comparison with peptide-based optical and piezoelectrical sensors in terms of analytical performance is presented. Methods of foodstuffs pretreatment are also discussed

Correlated quantification using microbiological and electrochemical assays for roxithromycin determination in biological and pharmaceutical samples

Microbiological and electrochemical assays, applying the cylinder-plate and differential pulse voltammetry as techniques, are reported for the quantitative determination of roxithromycin in serum and solid pharmaceutical form. The microbiological assay is based upon the inhibitory effect of this drug on the strain Bacillus subtilis ATCC 9372 used as the test microorganism. Linearity of the calibration curve was observed over the concentration range of 8.37-83.70 μg mL-1, with relative standard deviation values less than 5.0%. The electrochemical behavior of roxithromycin was studied at a graphite screen-printed electrode modified with graphene by using cyclic voltammetry and differential pulse voltammetry. The current value of the oxidative peak obtained for roxithromycin at 0.65 V vs. Ag/AgCl in 0.03 mol L-1 phosphate buffer solution (pH 7.0) with a scan rate of 0.1 V-1 is a linear function of the concentration in a range of 4.19-83.70 μg mL-1 (5-100 μmol L-1). A comparative study was carried out and both methods were applied for the determination of roxithromycin in solid dosage forms and spiked serum. The bioassay results of human serum samples were in accordance with the electrochemical ones (R2 = 0.988, P < 0.001), and the Bland-Altman method also showed good agreement between the values obtained by both procedures. Moreover, the statistical comparison indicated that there was no significant difference between the proposed techniques regarding both accuracy and precision.status: publishe

Electrochemical Sensor for the Evaluation of Doxorubicin from Novel Pharmaceutical Formulations and Serum

This study focuses on addressing the challenges associated with doxorubicin (DOX), an anthracycline chemotherapeutic widely used in cancer treatment. Despite its efficacy, DOX is linked to severe side effects that limit its clinical applications. Novel pharmaceutical formulations aim to mitigate these issues, providing better safety profiles. The development of these formulations requires analytical methods that can accurately and quickly quantify DOX. A cost-effective and portable electrochemical sensor for DOX detection was developed utilizing in-house printed carbon electrodes decorated with gold nanoparticles. DOX was detected using differential pulse voltammetry. The sensor demonstrated an accurate quantification of DOX from novel pharmaceutical formulations and serum, presenting a dynamic range of 1 to 500 μg/mL and a low detection limit of 0.3 μg/mL. The method, successfully applied to characterize DOX-loaded nanosomes, offers a valuable alternative in the early stages of formulation development, reducing costs and saving time, while maintaining accuracy