4-Aminophenyl boronic acid modified gold platforms for influenza diagnosis

Carboranylphosphines: B9-Substituted Derivatives with Enhanced Reactivity for the Anchoring to Dendrimers

Several ortho-carboranes bearing a phenoxy or a phenylamino group in the B9 position were prepared employing various protection and deprotection strategies. Following established protocols, dendritic compounds were synthesized from a hexachlorocyclotriphosphazene or thiophosphoryl chloride core, and possible anchoring options for the B9-substituted ortho-carboranes were investigated experimentally and theoretically (DFT). Furthermore, 1- or 1,2-phosphanyl-substituted carborane derivatives were obtained. The resulting diethyl-, diisopropyl-, di-tert-butyl-, diphenyl- or diethoxyphosphines bearing a tunable ortho-carborane moiety are intriguing ligands for future applications in homogeneous catalysis or the medicinal sector.

Electro-Nano Diagnostic Platform Based on Antibody-Antigen Interaction: An Electrochemical Immunosensor for Influenza A Virus Detection

H1N1 is a kind of influenza A virus that causes serious health issues throughout the world. Its symptoms are more serious than seasonal flu and can sometimes be lethal. For this reason, rapid, accurate, and effective diagnostic tests are needed. In this study, an electrochemical immunosensor for the sensitive, selective, and practical detection of the H1N1 virus was developed. The sensor platform included multi-walled carbon nanotube gold-platinum (MWCNT-Au-Pt) hybrid nanomaterial and anti-hemagglutinin (anti-H1) monoclonal antibody. For the construction of this biosensor, a gold screen-printed electrode (AuSPE) was used as a transducer. Firstly, AuSPE was modified with MWCNT-Au-Pt hybrid nanomaterial via drop casting. Anti-H1 antibody was immobilized onto the electrode surface after the modification process with cysteamine was applied. Then, the effect of the interaction time with cysteamine for surface modification was investigated. Following that, the experimental parameters, such as the amount of hybrid nanomaterial and the concentration of anti-H1 were optimized. Under the optimized conditions, the analytical characteristics of the developed electrochemical immunosensor were investigated for the H1N1 virus by using electrochemical impedance spectroscopy. As a result, a linear range was obtained between 2.5-25.0 µg/mL with a limit of the detection value of 3.54 µg/mL. The relative standard deviation value for 20 µg/mL of the H1N1 virus was also calculated and found as 0.45% (n = 3). In order to determine the selectivity of the developed anti-H1-based electrochemical influenza A immunosensor, the response of this system towards the H3N2 virus was investigated. The matrix effect was also investigated by using synthetic saliva supplemented with H1N1 virus.

Application of Nanobiotechnology for Early Diagnosis of SARS-CoV-2 Infection in the COVID-19 Pandemic

A most discussed topic of the new decade, COVID-19 is an infectious disease caused by the recently discovered SARS-CoV-2. With an exceedingly high transmission rate, COVID-19 has affected almost all the countries in the world. Absent any vaccine or specific treatment, the humanity is left with nothing but the legacy method of quarantine. However, quarantine can only be effective when combined with early diagnosis of suspected cases. With their high sensitivity and unmatched specificity, biosensors have become an area of interest for development of novel diagnostic methods. Compared to the more traditional diagnostics, nanobiotechnology introduces biosensors as different diagnostics with greater versatility in application. Today, a growing number of analytes are being accurately identified by these nanoscopic sensing machines. Several reports of validated application with real samples further strengthen this idea. As of recent, there has been a rise in the number of studies on portable biosensors. Despite the slow progression, certain devices with embedded biosensors have managed to be of diagnostic value in several countries. The perceptible increase in development of mobile platforms has revolutionized the healthcare delivery system in the new millennium. The present article reviews the most recent advancements in development of diagnostic nanobiosensors and their application in the clinical fields. KEY POINTS: • There is no specific treatment for highly transmissible SARS-CoV-2. • Early diagnosis is critical for control of pandemic. • Highly sensitive/specific nanobiosensors are emerging assets against COVID-19.

Nanobiosensors for the Detection of Novel Coronavirus 2019-nCoV and Other Pandemic/Epidemic Respiratory Viruses: A Review

The coronavirus disease 2019 (COVID-19) pandemic is considered a public health emergency of international concern. The 2019 novel coronavirus (2019-nCoV) or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that caused this pandemic has spread rapidly to over 200 countries, and has drastically affected public health and the economies of states at unprecedented levels. In this context, efforts around the world are focusing on solving this problem in several directions of research, by: (i) exploring the origin and evolution of the phylogeny of the SARS-CoV-2 viral genome; (ii) developing nanobiosensors that could be highly effective in detecting the new coronavirus; (iii) finding effective treatments for COVID-19; and (iv) working on vaccine development. In this paper, an overview of the progress made in the development of nanobiosensors for the detection of human coronaviruses (SARS-CoV, SARS-CoV-2, and Middle East respiratory syndrome coronavirus (MERS-CoV) is presented, along with specific techniques for modifying the surface of nanobiosensors. The newest detection methods of the influenza virus responsible for acute respiratory syndrome were compared with conventional methods, highlighting the newest trends in diagnostics, applications, and challenges of SARS-CoV-2 (COVID-19 causative virus) nanobiosensors.

Quartz crystal microbalance-based biosensors as rapid diagnostic devices for infectious diseases

Infectious diseases are the ever-present threats to public health and the global economy. Accurate and timely diagnosis is crucial to impede the progression of a disease and break the chain of transmission. Conventional diagnostic techniques are typically time-consuming and costly, making them inefficient for early diagnosis of infections and inconvenient for use at the point of care. Developments of sensitive, rapid, and affordable diagnostic methods are necessary to improve the clinical management of infectious diseases. Quartz crystal microbalance (QCM) systems have emerged as a robust biosensing platform due to their label-free mechanism, which allows the detection and quantification of a wide range of biomolecules. The high sensitivity and short detection time offered by QCM-based biosensors are attractive for the early detection of infections and the routine monitoring of disease progression. Herein, the strategies employed in QCM-based biosensors for the detection of infectious diseases are extensively reviewed, with a focus on prevalent diseases for which improved diagnostic techniques are in high demand. The challenges to the clinical application of QCM-based biosensors are highlighted, along with an outline of the future scope of research in QCM-based diagnostics.

Virus detection using nanosensors

A smart city has a bright and sustainable way to integrate services together and can monitor/control them using intelligent devices called sensors to preserve the efficient utilization of resources. Sensors are distributed everywhere in smart cities. They can be employed to monitor health care, transportation, infrastructure, building, surveillance, government, etc. Especially, nanosensors hold great impact to turn the current techniques for the detection of viruses. With the facility of real-time sensing, there is no need for regular inspections for maintenance and surveying, which results in reduced costs and time wastage. Definitely, common sensing platforms need persistent updates to address increasing doubts in the detection of viruses as they modify quickly and spread from person to person, pointing the urgency of early detection. In this chapter the introduction is briefly described in Section 30.1. The fundamental of nanosensors is explained in Section 30.2. The significance and applications of nanosensors in virus detection are extensively discussed in Sections 30.3 and 30.4. Section 30.5 consists of various challenges and outlook.

Capacitive Saccharide Sensor Based on Immobilized Phenylboronic Acid with Diol Specificity

A capacitive sensor for saccharide detection is described in this study. The detection is based on selective interaction between diols and aminophenylboronic acid (APBA) immobilized on a gold electrode. Glucose, fructose, and dextran (MW: 40 kDa) were tested with the system over wide concentration ranges (1.0 x 10-8 M - 1.0 x 10-3 M for glucose, 1.0 x 10-8 M - 1.0 x 10-2 M for fructose and 1.0 x 10-10 M - 1.0 x 10-5 M for dextran). The limits of detection (LODs) were 0.8 nM for glucose, 0.6 nM for fructose, and 13 pM for dextran. These data were comparable to the others reported previously. In order to demonstrate glycoprotein detection with the same sensor, human immunoglobulin G (IgG) as well as horseradish peroxidase were used as model analytes. The sensor responded to IgG in the concentration range of 1.0 x 10-13 M - 1.0 x 10-7 M with a LOD value of 16 fM. The performance of the assay of peroxidase was compared to a spectrophotometric assay by determining the enzymatic activity of a captured analyte. The results showed that the method might be useful for label-free, fast, and sensitive detection of saccharides as well as glycoproteins over a wide concentration range.

Proteinous Polymeric Shell Decorated Nanocrystals for the Recognition of Immunoglobulin M

This study demonstrates the preparation of photosensitively orientated and crosslinked proteinous polymeric shell having quantum dot based nanocrystals through Amino acid Decorated and Light Underpinning Conjugation Approach (ANADOLUCA). ANADOLUCA is based on photo-electron transfer method and uses these decorated nanocrystals for specifically and effectively recognition and detection of Immunoglobulin M in the aqueous environment. The conjugation method effectively provides an orientation of affinity pairs on the surface of quantum dots nanocrystals. This photosensitive ruthenium-based amino acid monomer is a synthetic and inexpensive material for the preparation of bioconjugates. The nanocrystals give advantages for using a wide pH and temperature range. The construction and preparation method is applicable to silica materials, superparamagnetic particles, quantum dots, carbon nanotubes, Ag/Au nanoparticles, Au surfaces, and polymeric materials. This prepared proteinous polymeric shell decorated nanocrystals are of great potential in applications in life sciences and can be used in infection case studies or allergy symptoms.

Reversible Self-Assembled Monolayers (rSAMs): Adaptable Surfaces for Enhanced Multivalent Interactions and Ultrasensitive Virus Detection

We report on the design of pH-switchable monolayers allowing a reversible and ordered introduction of affinity reagents on sensor surfaces. The principal layer building blocks consist of α-(4-amidinophenoxy)alkanes decorated at the ω-position with affinity ligands. These spontaneously self-assemble on top of carboxylic acid terminated SAMs to form reversible homo or mixed monolayers (rSAMs) that are tunable with respect to the nature of the head group, layer order and stability while featuring pH responsiveness and the dynamic nature of noncovalent build assemblies. We show that this results in a range of unique biosensor features. As a first example a sialic acid rSAM featuring strong lectin affinity is here used to sense hemagglutinin and influenza virus (H5N1) at the pM and fM level by in situ ellipsometry in a fully reversible fashion. We believe that the rSAM concept will find widespread use in surface chemistry and overall for boosting sensitivity in affinity biosensors.

Molecular Imprinting of Macromolecules for Sensor Applications

Molecular recognition has an important role in numerous living systems. One of the most important molecular recognition methods is molecular imprinting, which allows host compounds to recognize and detect several molecules rapidly, sensitively and selectively. Compared to natural systems, molecular imprinting methods have some important features such as low cost, robustness, high recognition ability and long term durability which allows molecularly imprinted polymers to be used in various biotechnological applications, such as chromatography, drug delivery, nanotechnology, and sensor technology. Sensors are important tools because of their ability to figure out a potentially large number of analytical difficulties in various areas with different macromolecular targets. Proteins, enzymes, nucleic acids, antibodies, viruses and cells are defined as macromolecules that have wide range of functions are very important. Thus, macromolecules detection has gained great attention in concerning the improvement in most of the studies. The applications of macromolecule imprinted sensors will have a spacious exploration according to the low cost, high specificity and stability. In this review, macromolecules for molecularly imprinted sensor applications are structured according to the definition of molecular imprinting methods, developments in macromolecular imprinting methods, macromolecular imprinted sensors, and conclusions and future perspectives. This chapter follows the latter strategies and focuses on the applications of macromolecular imprinted sensors. This allows discussion on how sensor strategy is brought to solve the macromolecules imprinting.

Erythrocytes-based quartz crystal microbalance cytosensor for in situ detection of cell surface sialic acid

Erythrocytes-based quartz crystal microbalance cytosensor forin situdetection of cell surface sialic acid using AuNPs/APBA signal amplification nanoprobe.

Synthesis and evaluation of temperature- and glucose-sensitive nanoparticles based on phenylboronic acid and N-vinylcaprolactam for insulin delivery

Poly N-vinylcaprolactam-co-acrylamidophenylboronic acid p(NVCL-co-AAPBA) was prepared from N-vinylcaprolactam (NVCL) and 3-acrylamidophenylboronic acid (AAPBA), using 2,2-azobisisobutyronitrile (AIBN) as initiator. The synthesis and structure of the polymer were examined by Fourier Transform infrared spectroscopy (FT-IR) and (1)H-NMR. Dynamic light scattering (DLS), lower critical solution temperature (LCST) and transmission electron microscopy (TEM) were utilized to characterize the nanoparticles, CD spectroscopy was used to determine if there were any changes to the conformation of the insulin, and cell and animal toxicity were also investigated. The prepared nanoparticles were found to be monodisperse submicron particles and were glucose- and temperature-sensitive. In addition, the nanoparticles have good insulin-loading characteristics, do not affect the conformation of the insulin and show low-toxicity to cells and animals. These p(NVCL-co-AAPBA) nanoparticles may have some value for insulin or other hypoglycemic protein delivery.

Quartz-Crystal Microbalance (QCM) for Public Health: An Overview of Its Applications

Nanobiotechnologies, from the convergence of nanotechnology and molecular biology and postgenomics medicine, play a major role in the field of public health. This overview summarizes the potentiality of piezoelectric sensors, and in particular, of quartz-crystal microbalance (QCM), a physical nanogram-sensitive device. QCM enables the rapid, real time, on-site detection of pathogens with an enormous burden in public health, such as influenza and other respiratory viruses, hepatitis B virus (HBV), and drug-resistant bacteria, among others. Further, it allows to detect food allergens, food-borne pathogens, such as Escherichia coli and Salmonella typhimurium, and food chemical contaminants, as well as water-borne microorganisms and environmental contaminants. Moreover, QCM holds promises in early cancer detection and screening of new antiblastic drugs. Applications for monitoring biohazards, for assuring homeland security, and preventing bioterrorism are also discussed.

Boronic acids for sensing and other applications - a mini-review of papers published in 2013

Boronic acids are increasingly utilised in diverse areas of research. Including the interactions of boronic acids with diols and strong Lewis bases as fluoride or cyanide anions, which leads to their utility in various sensing applications. The sensing applications can be homogeneous assays or heterogeneous detection. Detection can be at the interface of the sensing material or within the bulk sample. Furthermore, the key interaction of boronic acids with diols allows utilisation in various areas ranging from biological labelling, protein manipulation and modification, separation and the development of therapeutics. All the above uses and applications are covered by this mini-review of papers published during 2013.

An immunosensor based on antibody binding fragments attached to gold nanoparticles for the detection of peptides derived from avian influenza hemagglutinin H5

This paper concerns the development of an immunosensor for detection of peptides derived from avian influenza hemagglutinin H5. Its preparation consists of successive gold electrode modification steps: (i) modification with 1,6-hexanedithiol and gold colloidal nanoparticles; (ii) immobilization of antibody-binding fragments (Fab') of anti-hemagglutinin H5 monoclonal antibodies Mab 6-9-1 via S-Au covalent bonds; and (iii) covering the remaining free space on the electrode surfaces with bovine serum albumin. The interactions between Fab' fragments and hemagglutinin (HA) variants have been explored with electrochemical impedance spectroscopy (EIS) in the presence of [Fe(CN)6](3-/4-) as an electroactive marker. The immunosensor was able to recognize three different His-tagged variants of recombinant hemagglutinin from H5N1 viruses: H1 subunit (17-340 residues) of A/swan/Poland/305-135V08/2006, the long HA (17-530 residues) A/Bar-headed Goose/Qinghai/12/2005 and H1 subunit (1-345 residues) of A/Vietnam/1194/2004. The strongest response has been observed for the long variant with detection limit of 2.2 pg/mL and dynamic range from 4.0 to 20.0 pg/mL.