Diamine Oxidase-Conjugated Multiwalled Carbon Nanotubes to Facilitate Electrode Surface Homogeneity

Carbon nanomaterials have gained significant interest over recent years in the field of electrochemistry, and they may be limited in their use due to issues with their difficulty in dispersion. Enzymes are prime components for detecting biological molecules and enabling electrochemical interactions, but they may also enhance multiwalled carbon nanotube (MWCNT) dispersion. This study evaluated a MWCNT and diamine oxidase enzyme (DAO)-functionalised screen-printed electrode (SPE) to demonstrate improved methods of MWCNT functionalisation and dispersion. MWCNT morphology and dispersion was determined using UV-Vis spectroscopy (UV-Vis) and scanning electron microscopy (SEM). Carboxyl groups were introduced onto the MWCNT surfaces using acid etching. MWCNT functionalisation was carried out using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) and N-Hydroxysuccinimide (NHS), followed by DAO conjugation and glutaraldehyde (GA) crosslinking. Modified C-MWNCT/EDC-NHS/DAO/GA was drop cast onto SPEs. Modified and unmodified electrodes after MWCNT functionalisation were characterised using optical profilometry (roughness), water contact angle measurements (wettability), Raman spectroscopy and energy dispersive X-ray spectroscopy (EDX) (vibrational modes and elemental composition, respectively). The results demonstrated that the addition of the DAO improved MWCNT homogenous dispersion and the solution demonstrated enhanced stability which remained over two days. Drop casting of C-MWCNT/EDC-NHS/DAO/GA onto carbon screen-printed electrodes increased the surface roughness and wettability. UV-Vis, SEM, Raman and EDX analysis determined the presence of carboxylated MWCNT variants from their non-carboxylated counterparts. Electrochemical analysis demonstrated an efficient electron transfer rate process and a diffusion-controlled redox process. The modification of such electrodes may be utilised for the development of biosensors which could be utilised to support a range of healthcare related fields.

Resonator nanophotonic standing-wave array trap for single-molecule manipulation and measurement

Nanophotonic tweezers represent emerging platforms with significant potential for parallel manipulation and measurements of single biological molecules on-chip. However, trapping force generation represents a substantial obstacle for their broader utility. Here, we present a resonator nanophotonic standing-wave array trap (resonator-nSWAT) that demonstrates significant force enhancement. This platform integrates a critically-coupled resonator design to the nSWAT and incorporates a novel trap reset scheme. The nSWAT can now perform standard single-molecule experiments, including stretching DNA molecules to measure their force-extension relations, unzipping DNA molecules, and disrupting and mapping protein-DNA interactions. These experiments have realized trapping forces on the order of 20 pN while demonstrating base-pair resolution with measurements performed on multiple molecules in parallel. Thus, the resonator-nSWAT platform now meets the benchmarks of a table-top precision optical trapping instrument in terms of force generation and resolution. This represents the first demonstration of a nanophotonic platform for such single-molecule experiments.

Nanoparticles: tech trends in healthcare

Nanotechnology is the use of matter on an atomic, molecular, and supramolecular scale for various purposes. Nanotechnology field of application is very much diverse which includes surface science, organic chemistry, molecular biology, semiconductor physics, energy storage, engineering, microfabrication, and molecular engineering. Its medical application ranges from biological devices, nano-electronic biosensors, and to future biological machines. The main issue nowadays for nanomedicine involve understanding the issues related to toxicity and environmental impact of nanoscale materials. Lot more functionalities can be added to nanomaterials by interfacing them with biological structures. The size of nanomaterials is similar most biological molecules and so useful for both in vivo and in vitro biomedical research and applications. The integration of nanomaterials with biology had paved path to the development of diagnostic devices, contrast agents, analytical tools, physical therapy applications and drug delivery vehicles.

Radiation Modulated Spin coupling in double-stranded DNA model

The spin activity in macromolecules such as DNA and oligopeptides, in the context of the Chiral Induced Spin Selectivity (CISS) has been proposed to be due to the atomic Spin-Orbit Coupling (SOC) and the associated chiral symmetry of the structures. This coupling, associated with carbon, nitrogen, and oxygen atoms in biological molecules, albeit small (meV), can be enhanced by the geometry, and strong local polarization effects such as hydrogen bonding (HB). A novel way to manipulate the spin degree of freedom is by modifying the spectrum using a coupling to the appropriate electromagnetic radiation field. Here we use the Floquet formalism in order to show how the half-filled band Hamiltonian for DNA, can be modulated by the radiation to produce up to a tenfold increase of the effective SOC once the intrinsic coupling is present. On the other hand, the chiral model, once incorporating the orbital angular momentum of electron motion on the helix, opens a gap for different helicity states (helicity splitting) that chooses spin polarization according to transport direction and chirality, without breaking time-reversal symmetry. The observed effects are feasible in physically reasonable parameter ranges for the radiation field amplitude and frequency.

Complex Energies and Transition-Dipoles for the Uracil anion Shape-type Resonances from stabilization curves via Padé

Absorption of slow moving electrons by neutral ground state nucleobases have been known to produce resonance, metastable, states. There are indications that such metastable states may play a key-role in DNA/RNA damage. Therefore, herein, we present an ab-initio, non-Hermitian investigation of the resonance positions and decay rates of the low lying shape-type states of the uracil anion. In addition, we calculate the complex transition dipoles between these resonance states. We employ the resonance via Padé (RVP) method to calculate these complex properties from real stabilization curves by analytical dilation into the complex plane. This method has al-ready been successfully applied to many small molecular systems and herein we present the first application of RVP to a medium-size system. The presented resonance energies are converged with respect to the size of the basis set and compared with previous theoretical works and experimental findings. Complex transition dipoles between the shape-type resonances are computed using the energy-converged basis set. The ability to calculate ab-initio energies and lifetimes of biologically relevant systems opens the door for studying reactions of such systems in which autoionization takes place. While the ability to also calculate their complex transition dipoles open the door for studying photo induced dynamics of such biological molecules.

Biomedical Applications of Nanoparticles

In recent years, there has been significant growth and burgeoning interest in utilizing nanoparticles for various biomedical applications, including medical diagnostics, targeted drug delivery, tissue engineering, regenerative medicine, and biomedical textiles. In particular, nanoparticles functionalized with biological molecules have unique properties and are very effective in medical diagnostics. Besides that, nanoparticles have a wide range of therapeutic applications, including the development of nanodrug delivery systems, the design of novel drugs, as well as their contribution to the design of therapeutic materials. This chapter provides an overview of recent advancements in the biomedical applications of nanoparticles. Finally, this chapter discusses the challenges of the toxicological evaluation of engineered nanoparticles and the importance of conducting detailed studies on the synthesis of future nanomaterials to develop cutting-edge technologies for addressing a wide range of biomedical issues.

Biogenic Synthesis of Silver Nanoparticles, Characterization and Their Applications—A Review

With the growing awareness for the need of sustainable environment, the importance of synthesizing and the application of green nanoparticles has gained special focus. Among various metal nanoparticles, silver nanoparticles (AgNPs) have gain significant attention. AgNPs are synthesized conventionally by physical and chemical methods using chemicals such as reducing agents, which are hazardous to environment due to their toxic properties, provoking a serious concern to create and develop environment friendly methods. Thus, biological alternatives are emerging to fill gaps, such as green syntheses that use biological molecules taken from plant sources in the form of extracts, which have shown to be superior to chemical and physical approaches. These biological molecules derived from plants are assembled in a highly regulated manner to make them suitable for metal nanoparticle synthesis. The current review outlines the wide plant diversity that may be used to prepare a rapid and single-step procedure with a green path over the traditional ones, as well as their antifungal activity.

Multiple Scattering by Two PEC Spheres Using Translation Addition Theorem

An analysis of multiple scattering by two Perfect Electric Conducting (PEC) spheres using translation Addition Theorem (AT) for spherical vector wave functions is presented. Specifically, the Cruzan formalism is used to represent the AT for spherical harmonics, which introduces the translation coefficients for transformation of spherical harmonics from one coordinate to another. The adoption of these coefficients with the use of two PEC spheres in a near zone region makes the calculation of multiple scattering electric fields very efficient. As an illustration, the mathematical formation using advanced computational approaches was inspected. Then, the generic truncation criteria in the scattered electric field by two PEC spheres was deeply investigated using translation AT. However, the numerical validation was obtained using Comsol simulation software. This approach will allow to evaluate the scattering from macro-structures composed of spherical particles, i.e., biological molecules, clouds of airborne particles, etc. An original and fully general solution to the problem using vector quantities is introduced, and the convergence of the solution in several numerical examples is also demonstrated. This approach takes into account the effect of multiple scattering by two PEC spheres for spherical vector function.

A Comprehensive Review on the Heavy Metal Toxicity and Sequestration in Plants

Heavy metal (HM) toxicity has become a global concern in recent years and is imposing a severe threat to the environment and human health. In the case of plants, a higher concentration of HMs, above a threshold, adversely affects cellular metabolism because of the generation of reactive oxygen species (ROS) which target the key biological molecules. Moreover, some of the HMs such as mercury and arsenic, among others, can directly alter the protein/enzyme activities by targeting their –SH group to further impede the cellular metabolism. Particularly, inhibition of photosynthesis has been reported under HM toxicity because HMs trigger the degradation of chlorophyll molecules by enhancing the chlorophyllase activity and by replacing the central Mg ion in the porphyrin ring which affects overall plant growth and yield. Consequently, plants utilize various strategies to mitigate the negative impact of HM toxicity by limiting the uptake of these HMs and their sequestration into the vacuoles with the help of various molecules including proteins such as phytochelatins, metallothionein, compatible solutes, and secondary metabolites. In this comprehensive review, we provided insights towards a wider aspect of HM toxicity, ranging from their negative impact on plant growth to the mechanisms employed by the plants to alleviate the HM toxicity and presented the molecular mechanism of HMs toxicity and sequestration in plants.

An Updated Review on Nanomaterials for Biomedical Advancements: Concepts and Applications

The sphere of Nanotechnology encompasses most of our lives and houses biomedicine and biomedical advancements. Nanoparticles owing to their minuscule sizes and due to various physicochemical and electrical properties have been exploited in pharmaceutical industries, agriculture, packaging, cosmetic, food industries. Nanomedicine is a laboratory-designed molecular-level pharmaceutical material that has revolutionized diagnostic techniques and therapeutics. Nanoscience and nanotechnology and their wide applications have become spread field worldwide because nanomaterials have novel and unique properties. Nanotechnology involves understanding and manipulating materials normally in the size range of 1 to 100 nm, where they show completely novel physicochemical properties from their bulk counterpart. The capacity to study compounds at the molecular level has aided the hunt for materials with exceptional qualities for medical applications. Nanotechnology in recent days is applied in the designing of nano biosensors. Nanobiosensors are biological molecules immobilized onto the surface of a signal transducer. The application of nano biosensors in the field of disease detection has increased in recent years which has influenced in research of cancer and biosensing. Due to the high surface area of nanoparticles, they are important in the production of nano biosensors with high levels of sensitivity and diminish the response times. However, a comprehensive review regarding the type, mode of function, and their application in various diseases is missing. Nano Deterministic lateral displacement technology that provided exosome splitting based on size differences has resulted in providing the much-needed boost to cancer research. The time taken for cancer screening has been reduced drastically. that This review aims to describe the utilization of nano deterministic lateral displacement technology, nano biosensors, and their applications in certain disease diagnoses.