Toward the Ultimate Limit of Analyte Detection, in Graphene-Based Field-Effect Transistors.

The ultimate sensitivity of field-effect-transistor (FET)-based devices for ionic species detection is of great interest, given that such devices are capable of monitoring single-electron-level modulations. It is shown here, from both theoretical and experimental perspectives, that for such ultimate limits to be approached the thermodynamic as well as kinetic characteristics of the (FET surface)-(linker)-(ion-receptor) ensemble must be considered. The sensitivity was probed in terms of optimal packing of the ensemble, through a minimal charge state/capacitance point of view and atomic force microscopy.

CRISPR-Cas-Based Biomonitoring for Marine Environments: Toward CRISPR RNA Design Optimization Via Deep Learning.

Almost all of Earth's oceans are now impacted by multiple anthropogenic stressors, including the spread of nonindigenous species, harmful algal blooms, and pathogens. Early detection is critical to manage these stressors effectively and to protect marine systems and the ecosystem services they provide. Molecular tools have emerged as a promising solution for marine biomonitoring.

Graphene and Two-Dimensional Materials for Biomolecule Sensing.

An ideal biosensor material at room temperature, with an extremely large surface area per unit mass combined with the possibility of harnessing quantum mechanical attributes, would be comprised of graphene and other two-dimensional (2D) materials. The sensing of a variety of sizes and types of biomolecules involves modulation of the electrical charge density of (current through) the 2D material and manifests through specific components of the capacitance (resistance). While sensitive detection at the single-molecule level, i.

Rapid self-test of unprocessed viruses of SARS-CoV-2 and its variants in saliva by portable wireless graphene biosensor.

We have developed a DNA aptamer-conjugated graphene field-effect transistor (GFET) biosensor platform to detect receptor-binding domain (RBD), nucleocapsid (N), and spike (S) proteins, as well as viral particles of original Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) coronavirus and its variants in saliva samples. The GFET biosensor is a label-free, rapid (≤20 min), ultrasensitive handheld wireless readout device. The limit of detection (LoD) and the limit of quantitation (LoQ) of the sensor are 1.

Ion channel formation by N-terminally truncated Aβ (4-42): relevance for the pathogenesis of Alzheimer's disease.

Aβ deposition is a pathological hallmark of Alzheimer's disease (AD). Besides the full-length amyloid forming peptides (Aβ and Aβ), biochemical analyses of brain deposits have identified a variety of N- and C-terminally truncated Aβ variants in sporadic and familial AD patients. However, their relevance for AD pathogenesis remains largely understudied.

MRI reporter gene MagA suppresses transferrin receptor and maps Fe dependent lung cancer.

As a magnetic resonance imaging (MRI) reporter gene, MagA has become a powerful tool to monitor dynamic gene expression and allowed concomitant high resolution anatomical and functional imaging of subcellular genetic information. Here we establish a stably expressed MagA method for lung cancer MRI. The results show that MagA can not only enhance both in vitro and in vivo MRI contrast by specifically alternating the transverse relaxation rate of water, but also inhibit the malignant growth of lung tumor.

Graphene Oxide Quantum Dot Alters Amyloidogenicity of Hen Egg White Lysozyme via Modulation of Protein Surface Character.

A series of neurodegenerative disorders are caused by intracellular or extracellular amyloid deposition, including Alzheimer's disease, Parkinson's disease, Prion disease, and so on. To prevent the progress of such amyloid-mediated disorders, various agents have been tested including nanoparticles. Among different nanomaterials, graphene oxide shows unique electrochemical properties, which have potential applications in various biomedical fields.

DNA Nanotweezers and Graphene Transistor Enable Label-Free Genotyping.

Electronic DNA-biosensor with a single nucleotide resolution capability is highly desirable for personalized medicine. However, existing DNA-biosensors, especially single nucleotide polymorphism (SNP) detection systems, have poor sensitivity and specificity and lack real-time wireless data transmission. DNA-tweezers with graphene field effect transistor (FET) are used for SNP detection and data are transmitted wirelessly for analysis.

Multifunctional stimuli responsive polymer-gated iron and gold-embedded silica nano golf balls: Nanoshuttles for targeted on-demand theranostics.

Multi-functional nanoshuttles for remotely targeted and on-demand delivery of therapeutic molecules and imaging to defined tissues and organs hold great potentials in personalized medicine, including precise early diagnosis, efficient prevention and therapy without toxicity. Yet, in spite of 25 years of research, there are still no such shuttles available. To this end, we have designed magnetic and gold nanoparticles (NP)-embedded silica nanoshuttles (MGNSs) with nanopores on their surface.

Gold-Embedded Hollow Silica Nanogolf Balls for Imaging and Photothermal Therapy.

Hybrid nanocarriers with multifunctional properties have wide therapeutic and diagnostic applications. We have constructed hollow silica nanogolf balls (HGBs) and gold-embedded hollow silica nanogolf balls (Au@SiO HGBs) using the layer-by-layer approach on a symmetric polystyrene (PS) Janus template; the template consists of smaller PS spheres attached to an oppositely charged large PS core. ζ Potential measurement supports the electric force-based template-assisted synthesis mechanism.

Protein functionalization of ZnO nanostructure exhibits selective and enhanced toxicity to breast cancer cells through oxidative stress-based cell death mechanism.

Zinc oxide nanostructure (ZnONS) was chemically synthesized and functionalized (FZnONS) with a small protein bovine α-lactalbumin (BLA) by chemical cross-linking methods. Both nano-structures were characterized using various techniques such as electron microscopy, dynamic light scattering (DLS), UV-Vis spectroscopy, FT-IR, photo-luminescence and X-ray diffraction. Electron microscopy and DLS analysis revealed their (ZnONS and FZnONS) average size of 200nm and 450nm, respectively.

Nano Zinc Oxide Inhibits Fibrillar Growth and Suppresses Cellular Toxicity of Lysozyme Amyloid.

Deposition of amyloid fibers has been a common pathological event in many neurodegenerations, such as Alzheimer's disease, Parkinson's disease, and Prion disease. Although various therapeutic interventions have been reported, nanoparticles have recently been considered as possible inhibitors of amyloid fibrillation. Here, we reported the effect of three different forms of zinc oxide nanoparticles (ZnONP): uncapped (ZnONP), starch-capped (ZnONP), and self-assembled (ZnONP) (average sizes of 10, 30, and 163 nm, respectively), having a core size of 10-15 nm, in the amyloid growth of hen egg white lysozyme (HEWL).

Protein corona over silver nanoparticles triggers conformational change of proteins and drop in bactericidal potential of nanoparticles: Polyethylene glycol capping as preventive strategy.

Here, we demonstrated that starch-capped silver nanoparticles (AgNPST) with a size range of 10-15nm could readily interact with a small protein bovine α-lactalbumin (BLA) through the formation of protein corona. We further observed that such phenomena not only caused structural change of BLA but drastic drop in the bactericidal potential of AgNP. To design a strategy towards minimizing protein adsorption and maximizing the retention of bactericidal potential of AgNP, we developed stable polyethylene glycol (PEG)-capped AgNP (AgNPPEG) that clearly demonstrated reduced conformational changes of protein and retention of substantial bactericidal potential of AgNPPEG, compared to AgNPST.

Zinc oxide nanoparticles modulates the production of β-glucosidase and protects its functional state under alcoholic condition in Saccharomyces cerevisiae.

In the present investigation, we have investigated the effect of zinc oxide nanoparticles (ZnONP) on the production of β-glucosidase (BGL) in Saccharomyces cerevisiae under various conditions. ZnONP was synthesized chemically and characterized using various standard techniques. The results revealed that yeast culture administered with 5 mM ZnONP enhanced the intracellular BGL activity up to 28 % compared to control with simultaneous growth of cells.