Characterization and Evaluation of Nano-niosomes Encapsulating Docetaxel against Human Breast, Pancreatic, and Pulmonary Adenocarcinoma Cancer Cell Lines.

Background: Docetaxel (DXL) is an antineoplastic agent for cancer treatment, the therapeutic efficiency of which is limited due to low solubility, hydrophobicity, and tissue specificity. Objective: In this study, nano-niosomes were introduced for improving therapeutic index of DXL. Material and Methods: In this experimental study, two nano-niosomes were synthesized using Span 20® and Span 80® and a thin film hydration method with DXL loading (DXL-Span20 and DXL-Span80). Characterization, in-vitro cytotoxicity and bioavailability of the nano-niosomes was also evaluated via in-vivo experiments. Results: DXL-Span20 and DXL-Span80 have vesicles size in a range of 84-90 nm and negative zeta potentials. DXL entrapment efficiencies were obtained as 69.6 and 74.0% for DXL-Span20 and DXL-Span80, respectively; with an in-vitro sustained release patterns. Cytotoxicity assays were performed against MDA-MB-231, Calu-6, and AsPC-1 cell lines, and the results indicated that DXL loading into nano-niosomes led to decrement in values of half-maximal inhibitory concentration (IC50) at least 2.5 times and at most 6.5 times, compared to free DXL. Moreover, the rat blood bioavailability of DXL after intraperitoneal administration and the pharmacokinetic parameters indicated higher DXL plasma level and the higher effectiveness of DXL-Span80 compared to DXL-Span20. Conclusion: Carrying DXL by the nano-niosomes led to enhanced cytotoxicity (and lower IC50 values) and higher efficacy with enhanced pharmacokinetic parameters.

Synchronized Chemotherapy/Photothermal Therapy/Sonodynamic Therapy of Human Triple-Negative and Estrogen Receptor-Positive Breast Cancer Cells Using a Doxorubicin-Gold Nanoclusters-Albumin Nanobioconjugate.

OBJECTIVE: Novel strategies for treating triple-negative breast cancer (TNBC) are ongoing because of the lack of standard-of-care treatment. Nanoframed materials with a protein pillar are considered a valuable tool for designing multigoals of energy-absorbing/medication cargo and are a bridge to cross-conventional treatment strategies. METHODS: Nanobioconjugates of gold nanoclusters-bovine serum albumin (AuNCs-BSA) and doxorubicin-AuNCs-BSA (Dox-AuNCs-BSA) were prepared and employed as a simultaneous double photosensitizer/sonosensitizer and triple chemotherapeutic/photosensitizer/sonosensitizer, respectively. RESULTS: The highly stable AuNCs-BSA and Dox-AuNCs-BSA have ζ potentials of -29 and -18 mV, respectively, and represent valuable photothermal and sonodynamic activities for the combination of photothermal therapy and sonodynamic therapy (PTT/SDT) and synchronized chemotherapy/photothermal therapy/sonodynamic therapy (CTX/PTT/SDT) of human TNBC cells, respectively. The efficiency of photothermal conversion of AuNCs-BSA was calculated to be a promising value of 32.9%. AuNCs-BSA and Dox-AuNCs-BSA were activated on either laser light irradiation or ultrasound exposure with the highest efficiency on the combination of both types of radiation. CTX/PTT/SDT of MCF-7 and MDA-MB-231 breast cancer cell lines by Dox-AuNCs-BSA were evaluated with the MTT cell proliferation assay and found to progress synergistically. CONCLUSION: Results of the MTT assay, detection of the generation of intracellular reactive oxygen species and occurrence of apoptosis in the cells confirmed that CTX/PTT/SDT by Dox-AuNCs-BSA was attained with lower needed doses of the drug and improved tumor cell ablation, which would result in the enhancement of therapeutic efficacy and overcoming of therapeutic resistance.

Immunological mechanisms of the nucleocapsid protein in COVID-19.

The emergence of corona virus disease 2019 (COVID-19), resulting from Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has left an indelible mark on a global scale, causing countless infections and fatalities. This investigation delves into the role of the SARS-CoV-2 nucleocapsid (N) protein within the HEK293 cells, shedding light on its influence over apoptosis, interferon signaling, and cytokines production. The N gene was amplified, inserted into the pAdTrack-CMV vector, and then transfected to the HEK293 cells. Changes in the expression of IRF3, IRF7, IFN-ß, BAK, BAX, and BCL-2 genes were evaluated. The levels of proinflammatory cytokines of IL-6, IL-12, IL-1ß, and TNF-α were also determined. The N protein exhibited an anti-apoptotic effect by modulating critical genes associated with apoptosis, including BAK, BAX, and BCL-2. This effect potentially prolonged the survival of infected cells. The N protein also played a role in immune evasion by suppressing the interferon pathway, evidenced by the downregulation of essential interferon regulatory factors of IRF3 and IRF7, and IFN-ß expression. The N protein expression led to a substantial increase in the production of proinflammatory cytokines of IL-6, IL-12, IL-1ß, and TNF-α. The N protein emerged as a versatile factor and was exerted over apoptosis, interferon signaling, and cytokine production. These findings carry potential implications for the development of targeted therapies to combat COVID-19 and mitigate its global health impact.

A novel outlook in the delivery of artemisinin: production and efficacy in experimental visceral leishmaniasis.

The visceral form of leishmaniasis (VL), due to infection by Leishmania infantum, is a neglected tropical disease. The accessible therapeutic options are limited. Artemisinin is an efficient antileishmanial product with poor biological availability that requires high repetition of therapeutic doses in VL. Solid lipid nanoparticles (SLNs) provide targeted delivery, increase bioavailability and reduce toxicity of the traditional therapeutic strategy. The spherical shape artemisinin-loaded SLNs were prepared in a particle diameter of 222.0 ± 14.0 nm. The SLNs showed no particular toxic effect on the parasites, whereas the native artemisinin demonstrated a significant toxicity rate of 31% in viability of the promastigotes at the 250 µg/ml concentration. The therapeutic efficacy of the artemisinin-loaded SLNs was demonstrated in the experimental VL, using the L. infantum-infected BALB/c mice, in the present study. The 10 and 20 mg/kg doses of artemisinin-loaded SLNs showed higher level of antileishmanial efficacy compared with the free artemisinin. There was a significant diminishing of the parasite burden in liver (84.7 ± 4.9%) and spleen (85.0 ± 3.1%) and hepatosplenomegaly by the artemisinin-loaded SLNs treated at 20 mg/kg compared to the free artemisinin. Therefore, the present study supports the superior efficacy of artemisinin-loaded SLNs over the free artemisinin and could be considered as a new therapeutic strategy in the treatment of leishmaniasis.

Nucleic acid-based electrochemical biosensor for detection of influenza B by gold nanoparticles.

The influenza virus is a pervasive pathogen that exhibits increased prevalence during colder seasons, resulting in a significant annual occurrence of infections. Notably, pharmaceutical interventions effective against influenza A strains often exhibit limited efficacy against influenza B variants. Against this backdrop, the need for innovative approaches to accurately and swiftly differentiate and detect influenza B becomes evident. Biosensors play a pivotal role in this detection process, offering rapid, specific, and sensitive identification of the virus, facilitating timely intervention and containment efforts. Oligonucleotide sequences targeting the conserved B/Victoria/2/87 influenza virus NP region were designed. Nasopharyngeal swabs were collected from patients suspected of influenza virus infection, and viral RNA was extracted. RNA quality was assessed through one-step PCR. cDNA synthesis was performed using random hexamers, and real-time PCR quantified the influenza genome. Gold nanoparticles were immobilized on a surface to immobilize the specific DNA probe, and electrochemical hybridization was electrochemically followed. The biosensor exhibited high selectivity and effective distinction of complementary sequences from mismatches and influenza virus cDNA genome. The biosensor successfully detected the influenza B virus genome in real samples. Non-influenza samples yielded no significant hybridization signals. The comparison between the results obtained from the biosensor and real-time PCR revealed full agreement of these methods. The biosensor utilized electrochemical detection of hybridization and proved effective in detecting the influenza B virus genome with high specificity, sensitivity, and selectivity. Comparative analysis with real-time PCR underscored the accuracy and potential applicability of the biosensor in rapid and specific virus detection. This innovative approach holds promise for future diagnostic and epidemiological applications in detecting influenza B virus and other pathogens.

Electrochemical Immunosensors Developed for Amyloid-Beta and Tau Proteins, Leading Biomarkers of Alzheimer's Disease.

Alzheimer's disease (AD) is the most common neurological disease and a serious cause of dementia, which constitutes a threat to human health. The clinical evidence has found that extracellular amyloid-beta peptides (Aß), phosphorylated tau (p-tau), and intracellular tau proteins, which are derived from the amyloid precursor protein (APP), are the leading biomarkers for accurate and early diagnosis of AD due to their central role in disease pathology, their correlation with disease progression, their diagnostic value, and their implications for therapeutic interventions. Their detection and monitoring contribute significantly to understanding AD and advancing clinical care. Available diagnostic techniques, including magnetic resonance imaging (MRI) and positron emission tomography (PET), are mainly used to validate AD diagnosis. However, these methods are expensive, yield results that are difficult to interpret, and have common side effects such as headaches, nausea, and vomiting. Therefore, researchers have focused on developing cost-effective, portable, and point-of-care alternative diagnostic devices to detect specific biomarkers in cerebrospinal fluid (CSF) and other biofluids. In this review, we summarized the recent progress in developing electrochemical immunosensors for detecting AD biomarkers (Aß and p-tau protein) and their subtypes (AßO, Aß(1-40), Aß(1-42), t-tau, cleaved-tau (c-tau), p-tau181, p-tau231, p-tau381, and p-tau441). We also evaluated the key characteristics and electrochemical performance of developed immunosensing platforms, including signal interfaces, nanomaterials or other signal amplifiers, biofunctionalization methods, and even primary electrochemical sensing performances (i.e., sensitivity, linear detection range, the limit of detection (LOD), and clinical application).

A ß-Amyloid(1-42) Biosensor Based on Molecularly Imprinted Poly-Pyrrole for Early Diagnosis of Alzheimer's Disease.

BACKGROUND: Alzheimer's disease (AD) is a common form of dementia, characterized by production and deposition of ß-amyloid peptide in the brain. Thus, ß-amyloid peptide is a potentially promising biomarker used to diagnose and monitor the progression of AD. OBJECTIVE: The study aims to develop a biosensor based on a molecularly imprinted poly-pyrrole for detection of ß-amyloid. MATERIAL AND METHODS: In this experimental study, an imprinted poly-pyrrole was employed as an artificial receptor synthesized by electro-polymerization of pyrrole on screen-printed carbon electrodes in the presence of ß-amyloid. ß-amyloid acts as a molecular template within the polymer. The biosensor was evaluated by cyclic voltammetry using ferro/ferricyanide marker. The parameters influencing the biosensor performance, including electro-polymerization cycle umbers and ß-amyloid binding time were optimized to achieve the best biosensor sensitivity. RESULTS: The ß-amyloid binding affinity with the biosensor surface was evaluated by the Freundlich isotherm, and Freundlich constant and exponent were obtained as 0.22 ng mL-1 and 10.60, respectively. The biosensor demonstrated a detection limit of 1.2 pg mL-1. The biosensor was applied for ß-amyloid determination in artificial cerebrospinal fluid. CONCLUSION: The biosensor is applicable for early Alzheimer's disease detection.

Synthesis of Flower-like Nickel Hydroxide Nanosheets and Application in Electrochemical Determination of Famotidine.

An electrochemical sensor was designed and fabricated for electrocatalytic oxidation and determination of famotidine in pharmaceutical forms. The electrochemical oxidation process and its kinetics were investigated using cyclic voltammetry, steady-state polarization measurements, and chronoamperometry techniques, and also the analytical measurements were performed by amperometry. Upon addition of the drug into the solution, cyclic voltammograms of the fabricated sensor exhibited an increased anodic peak current associated with a decrease in the corresponding cathodic current. These results suggested an electrocatalytic EC' oxidation mechanism for famotidine on the oxyhydroxide species immobilized on the electrode surface. Accordingly, a mechanism involving generation of Ni3+ active sites and their subsequent consumption by the drug was proposed. Moreover, the corresponding rate law under the control of charge transfer was developed and kinetic parameters were derived. A sensitive and time-saving amperometric procedure was also developed for the analysis of famotidine with a detection limit of 5.91 mmol L-1. Using the developed amperometric procedure, famotidine was successfully analyzed in the presence of ibuprofen. The developed sensor in this study displayed enhanced sensitivity and selectivity, compared to some other reported methods.

A nanoemulsion-based delivery system for imatinib and in vitro anticancer efficacy

A self-nanoemulsifying drug delivery system (SNEDDS) composed of ethyl oleate, Tween 80 and polyethylene glycol 600 was prepared as a new route to improve the efficacy of imatinib. The drug-loaded SNEDDS formed nanodroplets of ethyl oleate stabilized by Tween 80 and polyethylene glycol 600 with a diameter of 81.0±9.5 nm. The nanoemulsion-based delivery system was stable for at least two months, with entrapment efficiency and loading capacity of 16.4±0.1 and 48.3±0.2%, respectively. Imatinib-loaded SNEDDS was evaluated for the drug release profiles, and its effectiveness against MCF-7 cell line was investigated. IC50 values for the imatinib-loaded SNEDDS and an imatinib aqueous solution were 3.1 and 6.5 µg mL-1, respectively.

An electrochemical peptide-based biosensor for the Alzheimer biomarker amyloid-ß(1-42) using a microporous gold nanostructure.

Alzheimer's disease (AD) is connected to aggregation of amyloid-ß (Aß) peptide and formation of insoluble plaques in the brain. Aß level can be monitored as an AD early diagnosis route. In this study, an irregular shaped microporous gold nanostructure with a typical size of 150 × 250 nm was electrodeposited on a polycrystalline gold surface at 0 mV (vs. AgCl) using sodium alendronate. The nanostructure was then characterized by field-emission scanning electron microscopy. An electrochemical peptide-based biosensor was fabricated by immobilizing an Aß(1-42)-binding peptide on the gold nanostructure. Binding of Aß(1-42) by the peptide was followed electrochemically using ferro/ferricyanide as a redox probe. Differential pulse voltammograms in a potential range of 0-500 mV (vs. AgCl) with typical peak potentials at 224 mV are linear in the 3-7000 pg mL-1 Aß(1-42) concentration range, with a 0.2 pg mL-1 detection limit. The biosensor is free of interferences and was applied to the quantitation of Aß(1-42) in artificial cerebrospinal fluid and spiked serum samples. Graphical abstractSchematic presentation of an immobilized amyloid-ß(1-42)-specific peptide on the surface of a microporous gold nanostructure to fabricate an electrochemical biosensor for early diagnosis of Alzheimer's disease. Aß(1-42) capturing by the peptide led to repulsion of ferrocyanide/ferricyanide redox couple.

An electrochemical troponin T aptasensor based on the use of a macroporous gold nanostructure.

A specific troponin T (TnT) binding aptamer was identified and immobilized on an electrodeposited macroporous gold nanostructure using poly(ethylene glycol) 600, to fabricate a novel and ultrasensitive TnT aptasensor. The transducer surface on the gold disk electrode was characterized by field emission scanning electron microscopy, and immobilization of the aptamer was monitored by open circuit potential measurements. Binding of TnT by the aptamer was monitored by differential pulse voltammetry using ferro/ferricyanide as the redox probe. The aptamer has a high affinity and specificity, and the electrode is sensitive and selective. Best operated at a working potential of 0.23 V (vs. Ag/AgCl), the electrode can detected TnT in the 0.05 to 5.0 ng mL-1 concentration range with a 23 pg mL-1 detection limit. The method was applied to the determination of TnT in 99 spiked human serum samples, and the diagnostic sensitivity and specificity were 94 and 95%, respectively. Graphical abstract Schematic presentation of an electrochemical troponin T aptasensor. A macroporous gold nanostructure was electrodeposited followed by immobilization of a specific TnT aptamer. Binding of TnT by the aptamer was electrochemically monitored. MCH: mercaptohexanol; TnT: troponin T.

A Cardiac Troponin T Biosensor Based on Aptamer Self-assembling on Gold.

In this study, a sensitive and accurate aptasensor was designed for early detection of myocardial infarction through the determination of troponin T (TnT). The successful immobilization of a specific aptamer sequence on the surface of gold that had a high affinity toward TnT was accomplished. TnT was electrochemically quantified. The results indicated that the aptasensor detected TnT in a range of 0.05-5 ng mL, and with a detection limit of 0.01 ng/mL. The performance of the aptasensor was investigated by analyzing 99 human serum samples. Both diagnostic specificity and sensitivity of the aptasensor were found to be 95%. The use of the designed aptamer-based biosensor could be an essential achievement in health policy, preventing deaths caused by myocardial infarction, and reducing patients with heart failure. The extensive use of this aptamer-based biosensor can also reduce costs, enhance speed, and improve accuracy in the diagnosis of TnT as an important myocardial infarction biomarker.

Applications of Nanoflowers in Biomedicine.

BACKGROUND: Nanotechnology has opened new windows for biomedical researches and treatment of diseases. Nanostructures with flower-like shapes (nanoflowers) which have exclusive morphology and properties have been interesting for many researchers. METHODS: In this review, various applications of nanoflowers in biomedical researches and patents from various aspects have been investigated and reviewed. RESULTS: Nanoflowers attracted serious attentions in whole biomedical fields such as cardiovascular diseases, microbiology, sensors and biosensors, biochemical and cellular studies, cancer therapy, healthcare, etc. The competitive power of nanoflowers against other in use technologies provides successful achievements in the progress of mentioned biomedical studies. CONCLUSION: The use of nanoflowers in biomedicine leads to improving accuracy, reducing time to achieve the results, reducing costs, creating optimal treatment conditions as well as avoiding side effects of the treatment of specific diseases, and increasing functional strength.

A signal-on built in-marker electrochemical aptasensor for human prostate-specific antigen based on a hairbrush-like gold nanostructure.

A green electrodeposition method was firstly employed for the synthesis of round hairbrush-like gold nanostructure in the presence of cadaverine as a size and shape directing additive. The nanostructure which comprised of arrays of nanospindles was then applied as a transducer to fabricate a signal-on built in-marker electrochemical aptasensor for the detection of human prostate-specific antigen (PSA). The aptasensor detected PSA with a linear concentration range of 0.125 to 128 ng mL-1 and a limit of detection of 50 pg mL-1. The aptasensor was then successfully applied to detect PSA in the blood serum samples of healthy and patient persons.

Biosynthesis of Silver Nanoparticles Using Pine Pollen and Evaluation of the Antifungal Efficiency.

Background: Nanoparticles have been applied to medicine, hygiene, pharmacy and dentistry, and will bring significant advances in the prevention, diagnosis, drug delivery and treatment of disease. Green synthesis of metal nanoparticles has a very important role in nanobiotechnology, allowing production of non-toxic and eco-friendly particles. Objectives: Green synthesis of silver nanoparticles (AgNPs) was studied using pine pollen as a novel, cost-effective, simple and non-hazardous bioresource. The antifungal activity of the synthesized AgNPs was investigated in vitro. Materials and Methods: Biosynthesis of AgNPs was conducted using pollen of pine (as a novel bioresource) acting as both reducing and capping agents. AgNPs were characterized using UV-visible spectroscopy, X-ray diffraction and transmission electron microscopy. In evaluation for antifungal properties, the synthesized AgNPs represented significant in vitro inhibitory effects on Neofusicoccum parvum cultures. Results: Pine pollen can mediate biosynthesis of colloidal AgNPs with an average size of 12 nm. AgNPs were formed at 22 °C and observed to be highly stable up to three months without precipitation or decreased antifungal property. AgNPs showed significant inhibitory effects against Neofusicoccum parvum. Conclusion: The first report for a low-cost, simple, well feasible and eco-friendly procedure for biosynthesis of AgNPs was presented. The synthesized AgNPs by pine pollen were nontoxic and eco-friendly, and can be employed for large-scale production. The nanoparticles showed strong effect on quantitative inhibition and disruption of antifungal growth.

Inhibitory Effects of Some Carbohydrates on Nano-Globular Aggregation of both Normal and Glycated Albumin.

BACKGROUND: Protein aggregation is one of the important, common and troubling problems in biotechnology, pharmaceutical industries and amyloid-re-lated disorders. METHODS: In the present study, the inhibitory effects of some carbohydrates (alginate, ß-cyclodextrin and trehalose) on the formation of nano-globular aggregates from normal (HSA) and glycated (GHSA) human serum albumin were studied; when the formation of aggregates was induced by the simultaneous heating and addition of dithiotheritol. For the investigations, the biophysical methods of UV-vis spectrophotometry, circular dichroism spectroscopy, transmission electron microscopy and tensiometry were employed. RESULTS: The effect of inhibitory mechanism of these inhibitors on the aggregation of HSA and GHSA was expressed and compared together. CONCLUSION: The results showed that the nucleus formation step of the aggregation process of HSA and GHSA was different in the presence of alginate (compared to ß-cyclodextrin and trehalose). The inhibition efficiencies of the carbohydrates on the aggregate formation of HSA and GHSA were different, arising from the differences in the hydrophobicities of HSA and GHSA, and also, the differences between HSA- and GHSA-carbohydrate interactions.

Synthesis and Applications of Nanoflowers.

BACKGROUND: Recent advances in nanotechnology make novel shapes of nanostructured materials with novel physicochemical properties. Different kinds of materials including carbon, metals, alloys, metal oxides, conducting polymers, metal chalcogenides, pnictides and fluorides have been synthesized with small size of <100 nm with shapes resembled to the natural flowers. The objective of this review is to provide a broad overview of the synthesis strategies, effects of different parameters on the morphology of nanoflowers, and their applications. METHODS: A comprehensive search to assess the current evidence for the synthesis routs of nanoflowers and applications was conducted. 487 studies became selected and the quality of papers were appraised and categorized according to type of nanomaterials. Within each section, the nanomaterials addressed specifically. In addition, recent patents were reviewed in a separate section. RESULTS: The nanoflowers exhibited unique properties which were utilized in the design of efficient applications. These nanostructures can be processed with different methods. The configuration of flower-like nanostructures can be controlled by altering experimental parameters, such as the precursor`s ratio, temperature and reaction time. Despite the huge efforts to control and understand the growth mechanism of these nanostructures, some fundamental phenomena are still not well understood. Investigation of the fundamental effects of size and morphology on their properties is required in order to better apply these nanostructured materials. CONCLUSION: The nanoflowers with interesting properties can be used in the design of future devices with various applications. The existence of different routes to synthesis nanoflowers and their unique properties confirm the importance promoted awareness of potential benefits of nanoflowers in different applications. The reviewed patents emphasized the importance of these nanostructures. Therefore, research efforts based on nanoflowers are dynamic and applicable in various fields.

Effect of Magnetic Fluid Hyperthermia on Implanted Melanoma in Mouse Models.

BACKGROUND: Nowadays, magnetic nanoparticles (MNPs) have received much attention because of their enormous potentials in many fields such as magnetic fluid hyperthermia (MFH). The goal of hyperthermia is to increase the temperature of malignant cells to destroy them without any lethal effect on normal tissues. To investigate the effectiveness of cancer therapy by magnetic fluid hyperthermia, Fe0.5Zn0.5Fe2O4 nanoparticles (FNPs) were used to undergo external magnetic field (f=515 kHz, H=100 G) in mice bearing implanted tumor. METHODS: FNPs were synthesized via precipitation and characterized using transmission electron microscopy (TEM), vibrating sample magnetometer, and Fourier transform infrared. For in vivo study, the mice bearing implanted tumor were divided into four groups (two mice per group), namely, control group, AMF group, MNPs group, and MNPs&AMF group. After 24 hours, the mice were sacrificed and each tumor specimen was prepared for histological analyses. The necrotic surface area was estimated by using graticule (Olympus, Japan) on tumor slides. RESULTS: The mean diameter of FNPs was estimated around 9 nm by TEM image and M versus H curve indicates that this particle is among superparamagnetic materials. According to histological analyses, no significant difference in necrosis extent was observed among the four groups. CONCLUSION: FNPs are biocompatible and have a good size for biomedical applications. However, for MFH approach, larger diameters especially in the range of ferromagnetic particles due to hysteresis loss can induce efficient heat in the target region.

Zepto-molar electrochemical detection of Brucella genome based on gold nanoribbons covered by gold nanoblooms.

Gold nanoribbons covered by gold nanoblooms were sonoelectrodeposited on a polycrystalline gold surface at -1800 mV (vs. AgCl) with the assistance of ultrasound and co-occurrence of the hydrogen evolution reaction. The nanostructure, as a transducer, was utilized to immobilize a Brucella-specific probe and fabrication of a genosensor, and the process of immobilization and hybridization was detected by electrochemical methods, using methylene blue as a redox marker. The proposed method for detection of the complementary sequence, sequences with base-mismatched (one-, two- and three-base mismatches), and the sequence of non-complementary sequence was assayed. The fabricated genosensor was evaluated for the assay of the bacteria in the cultured and human samples without polymerase chain reactions (PCR). The genosensor could detect the complementary sequence with a calibration sensitivity of 0.40 µA dm(3) mol(-1), a linear concentration range of 10 zmol dm(-3) to 10 pmol dm(-3), and a detection limit of 1.71 zmol dm(-3).

Amperometric Determination of Ascorbic Acid in Pharmaceutical Formulations by a Reduced Graphene Oxide-cobalt Hexacyanoferrate Nanocomposite.

Investigation of the redox properties of drugs and their determination are performed by electrochemical techniques. Data obtained from electrochemical techniques are often correlated with molecular structure and pharmacological activity of drugs. In this regard, different modified electrodes were applied as sensors for quantification of different drugs. A nanocomposite of reduced graphene oxide-cobalt hexacyanoferrate was synthesized by a simple precipitation route. Scanning electron microscopy revealed that the nanocomposite comprised nanoparticles of cobalt hexacyanoferrate attached to the reduced graphene oxide nanosheets. A nanocomposite-modified carbon paste electrode was then fabricated. It represented prominent activity toward the electrocatalytic oxidation of ascorbic acid, and the kinetics of the electrooxidation process was evaluated. Finally, an amperometric method was developed for the quantification of ascorbic acid in different pharmaceutical formulations.