Immunosensors

Immunosensors are solid-state devices in which the immunochemical reaction is coupled to a transducer. They form one of the most important classes of affinity biosensors based on the specific recognition of antigens by antibodies to form a stable complex, in a similar way to immunoassay. Depending on the type of transducer there are four types of immunosensor: electrochemical, optical, microgravimetric and thermometric. The most commonly used bioelements for the development of electrochemical immunosensors are antibodies (Ab), followed by aptamers (Apt) and, in the last five years, microRNA (miRNA). In order to perform an early diagnosis, a method that is able to measure peptides and proteins directly in a sample, without any sample pre-treatment or any separation, is preferred. This direct detection can be performed with methods making use of the specific interaction of proteins with Ab, Apt and miRNA. The recent developments made in the immunosensor field, regarding the incorporation of nanomaterials for increased sensitivity, multiplexing or microfluidic-based devices, may have potential for promising use in industry and clinical analysis. Some examples of assays for several commercially available biomarkers will be presented. The main application fields, beside biomedical analysis, are drug abuse control, food analysis and environmental analysis

New Materials for the Construction of Electrochemical Biosensors

The development of electrochemical sensors has attracted great interest due to these sensors’ high sensitivity and selectivity. Here, we present the general concept and the classification of biosensors, their advantages and drawbacks, the main strategies in electrochemical biosensor technology and the materials used in electrochemical sensors, such as electrodes and supporting substrates, materials for improved sensitivity and selectivity, materials for bioreceptor immobilization, and biological recognition elements. Various nanomaterials, such as carbon-based materials (carbon nanotubes, graphene, carbon nanoparticles), inorganic and organic nanoparticles (magnetic and metal nanoparticles, nanosized clays), conductive and insulating polymers (nanosized and nanostructured polymers, molecularly imprinted polymers), and hybrid materials, etc., have been successfully applied for the enhancement of the electroanalytical performance of biosensors and for the immobilization of biorecognition elements. Among these, due to their unique physiochemical features, carbon-based materials, such as carbon nanotubes and graphenes, have received special attention in recent years, and examples of surface functionalization using various types of nanoparticles are presented. The future trends in sensor research activities and areas of development that are expected to have an impact in biosensor performance, like immobilization techniques, nanotechnology, miniaturization and multisensor array determinations, are also examined

Editorial: electrochemical sensors and biosensors in medical and pharmaceutical bioanalysis

Producción CientíficaThis Research Topic collects different contributions in the emerging field of bioanalysis, highlighting the most relevant advances reported in the literature as well as some original research studies in medical and pharmaceutical bioanalysis. The first article of this Topic (Antonacci et al.), describes in a detailed review state of the art the paper-based electrochemical devices for pharmaceutical field. In the last few decades, scientific research has been trying to offer valid and reliable solutions to replace or support conventional techniques, in order to facilitate drug development procedures. These innovative approaches may have extremely positive effects in the production chain, supplying fast and cost-effective quality and safety tests on active pharmaceutical ingredients and their excipients. In this context, the exploitation of electrochemical paper-based analytical devices is still in its infancy, but particularly promising for its fascinating properties in the detection of active pharmaceutical ingredients and excipients in tablets, capsules, suppositories, and injections, as well as for pharmacokinetic bioanalysis in real samples

MUC1 MARKER FOR THE DETECTION OF OVARIAN CANCER. A REVIEW

Abstract Cancer is one of the leading causes of death, ovarian cancer being the seventh leading cause of cancer-related death among women and is associated with the highest morbidity of all the of gynecologic malignancies. Early stage tumor diagnosis is essential for a positive outcome for the patients, therefore it is of paramount importance to develop new, sensitive detection methods for tumor markers found in serum in early stages, in order to improve cancer survival rate. Mucin 1 (MUC1) is a transmembrane protein, heavily O-glycosylated, found on the apical plasma membrane of most secretory epithelia. In case of malignant processes MUC1 loses its apical distribution, is underglycosylated and overexpressed and is secreted into the blood circulation MUC1 has been identified as a marker for preneoplastic lesions, elevated levels of MUC1 protein being involved in tumor progression, especially in the process of metastasis The detection of low levels of MUC1 tumor marker plays an important role in the diagnosis, screening and prognosis of the ovarian cancer, therefore improvement of detection methods for this cancer biomarker and development of new, sensitive methods of detection, such as biosensors, is needed. Rezumat Cancerul reprezintă una dintre principale cauze ale mortalităţii, cancerul ovarian fiind a şaptea cauză a deceselor prin cancer în rândul femeilor şi totodată cea mai agresivă formă de cancer din sfera ginecologică. Diagnosticul precoce al tumorilor maligne este esenţial pentru un bun prognostic al bolii, de aceea pentru o rată crescută a supravieţuirii este deosebit de importantă dezvoltarea unor metode noi, sensibile de detecţie a markerilor tumorali prezenţi în sȃnge în stadiile incipiente de cancer. Mucina 1 (MUC1) este o proteină transmembranară, puternic O-glicozilată, care se găseşte pe suprafaţa apicală a celulelor din majoritatea ţesuturilor epiteliale secretorii. În cazul unui proces malign proteina MUC1 este supraexprimată şi hipoglicozilată, aceasta fiind secretată în sânge [1], făcând astfel posibilă utilizarea ei ca marker în cazul leziunilor preneoplazic

Pharmaceutical Development of Liposomes Using the QbD Approach

Quality by Design (QbD) is a systematic, risk-based approach to pharmaceutical product and manufacturing development, which uses quality-improving scientific methods upstream in the research, development, and design phases, in order to assure that quality and safety are designed into product at as early stage as possible. This work focuses on the state-of-the-art applications of the QbD principles in the development of liposomes. The QbD approach has recently been proposed as a useful tool to obtain higher-quality liposomal products, as their development is a challenging task, involving intricate formulation and manufacturing processes. Thus, the current strategies to define the relationship between the critical material attributes or process parameters and product critical quality attributes and to establish the design space are overviewed. Additionally, the current characterization methodologies are described, as part of the control strategy required within the QbD paradigm

CoRoLa Starts Blooming – An update on the Reference Corpus of Contemporary Romanian Language

This article reports on the on-going CoRoLa project, aiming at creating a reference corpus of contemporary Romanian (from 1945 onwards), opened for online free exploitation by researchers in linguistics and language processing, teachers of Romanian, students. We invest serious efforts in persuading large publishing houses and other owners of IPR on relevant language data to join us and contribute the project with selections of their text and speech repositories. The CoRoLa project is coordinated by two Computer Science institutes of the Romanian Academy, but enjoys cooperation of and consulting from professional linguists from other institutes of the Romanian Academy. We foresee a written component of the corpus of more than 500 million word forms, and a speech component of about 300 hours of recordings. The entire collection of texts (covering all functional styles of the language) will be pre-processed and annotated at several levels, and also documented with standardized metadata. The pre-processing includes cleaning the data and harmonising the diacritics, sentence splitting and tokenization. Annotation will include morpho-lexical tagging and lemmatization in the first stage, followed by syntactic, semantic and discourse annotation in a later stage

Spatio-temporal insights into microbiology of the freshwater-to-hypersaline, oxic-hypoxic-euxinic waters of Ursu Lake

Ursu Lake is located in the Middle Miocene salt deposit of Central Romania. It is stratified, and the water column has three distinct water masses: an upper freshwater-to-moderately saline stratum (0–3 m), an intermediate stratum exhibiting a steep halocline (3–3.5 m), and a lower hypersaline stratum (4 m and below) that is euxinic (i.e. anoxic and sulphidic). Recent studies have characterized the lake's microbial taxonomy and given rise to intriguing ecological questions. Here, we explore whether the communities are dynamic or stable in relation to taxonomic composition, geochemistry, biophysics, and ecophysiological functions during the annual cycle. We found: (i) seasonally fluctuating, light-dependent communities in the upper layer (≥0.987–0.990 water-activity), a stable but phylogenetically diverse population of heterotrophs in the hypersaline stratum (water activities down to 0.762) and a persistent plate of green sulphur bacteria that connects these two (0.958–0.956 water activity) at 3–3.5 to 4 m; (ii) communities that might be involved in carbon- and sulphur-cycling between and within the lake's three main water masses; (iii) uncultured lineages including Acetothermia (OP1), Cloacimonetes (WWE1), Marinimicrobia (SAR406), Omnitrophicaeota (OP3), Parcubacteria (OD1) and other Candidate Phyla Radiation bacteria, and SR1 in the hypersaline stratum (likely involved in the anaerobic steps of carbon- and sulphur-cycling); and (iv) that species richness and habitat stability are associated with high redox-potentials. Ursu Lake has a unique and complex ecology, at the same time exhibiting dynamic fluctuations and stability, and can be used as a modern analogue for ancient euxinic water bodies and comparator system for other stratified hypersaline systems

Special Issue “Women in Science”—The First Edition

This Special Issue entitled “Women in Biosensors” has been launched to celebrate and highlight the achievements of women in the biosensors research area, presenting biosensor-related work performed in groups leaded by women scientists [...

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)