A Field-Deployable Diagnostic Assay for the Visual Detection of Misfolded Prions

Diagnostic tools for the detection of protein-misfolding diseases (i.e., proteopathies) are limited. Gold nanoparticles (AuNPs) facilitate sensitive diagnostic techniques via visual color change for the detection of a variety of targets. In parallel, recently developed quaking-induced conversion (QuIC) assays leverage protein-amplification and fluorescent signaling for the accurate detection of misfolded proteins. Here, we combine AuNP and QuIC technologies for the visual detection of amplified misfolded prion proteins from tissues of wild white-tailed deer infected with chronic wasting disease (CWD), a prion disease of cervids. Our newly developed assay, MN-QuIC™, enables both naked-eye and light-absorbance measurements for detection of misfolded prions. MN-QuIC™ leverages basic laboratory equipment that is cost-effective and portable, thus facilitating real-time prion diagnostics across a variety of settings. To test the portability of our assay, we deployed to a rural field-station in southeastern Minnesota and tested for CWD on site. We successfully demonstrated that MN-QuIC™ is functional in a non-traditional laboratory setting by performing a blinded analysis in the field and correctly identifying all CWD positive and CWD not detected deer at the field site in less than 24 hours, thus documenting the portability of the assay. Additionally, we show that electrostatic forces help govern the AuNP/prion interactions. Importantly, all of our white-tailed deer (n=37) were independently tested using ELISA, IHC, and/or RT-QuIC technologies and results secured with MN-QuIC™ were 100% consistent with these tests. We conclude that hybrid AuNP and QuIC assays, such as MN-QuIC™, have great potential for sensitive, field-deployable diagnostics of a variety of protein misfolding diseases.

Download Full-text

Nanotechnology-Based Approaches for the Detection of SARS-CoV-2

Frontiers in Nanotechnology ◽

10.3389/fnano.2020.589832 ◽

2020 ◽

Vol 2 ◽

Author(s):

Ritika Gupta ◽

Poonam Sagar ◽

Nitesh Priyadarshi ◽

Sunaina Kaul ◽

Rajat Sandhir ◽

...

Keyword(s):

Point Of Care ◽

Resonance Energy Transfer ◽

Resonance Energy ◽

Cost Effective ◽

Diagnostic Techniques ◽

Localized Surface Plasmon ◽

Diagnostic Tools ◽

Diagnostic Systems ◽

Economic Activities ◽

Low Sensitivity

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as a pandemic has been validated as an extreme clinical calamity and has affected several socio-economic activities globally. Proven transmission of this virus occurs through airborne droplets from an infected person. The recent upsurge in the number of infected individuals has already exceeded the number of intensive care beds available to patients. These extraordinary circumstances have elicited the need for the development of diagnostic tools for the detection of the virus and, hence, prevent the spread of the disease. Early diagnosis and effective immediate treatment can reduce and prevent an increase in the number of cases. Conventional methods of detection such as quantitative real-time polymerase chain reaction and chest computed tomography scans have been used extensively for diagnostic purposes. However, these present several challenges, including prolonged assay requirements, labor-intensive testing, low sensitivity, and unavailability of these resources in remote locations. Such challenges urgently require fast, sensitive, and accurate diagnostic techniques for the timely detection and treatment of coronavirus disease 2019 (COVID-19) infections. Point-of-care biosensors that include paper- and chip-based diagnostic systems are rapid, cost-effective, and user friendly. In this article nanotechnology-based potential biosensors for SARS-CoV-2 diagnosis are discussed with particular emphasis on a lateral flow assay, a surface-enhanced Raman scattering-based biosensor, a localized surface plasmon resonance-based biosensor, Förster resonance energy transfer, an electrochemical biosensor, and artificial intelligence-based biosensors. Several biomolecules, such as nucleic acids, antibodies/enzymes, or aptamers, can serve as potential detection molecules on an appropriate platform, such as graphene oxide, nanoparticles, or quantum dots. An effective biosensor can be developed by using appropriate combinations of nanomaterials and technologies.

Download Full-text

A Facile Strategy for Immobilizing GOD and HRP onto Pollen Grain and Its Application to Visual Detection of Glucose

International Journal of Molecular Sciences ◽

10.3390/ijms21249529 ◽

2020 ◽

Vol 21 (24) ◽

pp. 9529

Author(s):

Shanxia Jin ◽

Liping Liu ◽

Mengying Fan ◽

Yaru Jia ◽

Ping Zhou

Keyword(s):

Visual Detection ◽

Color Change ◽

Cost Effective ◽

Pollen Grain ◽

Practical Application ◽

Horse Radish Peroxidase ◽

Experimental Conditions ◽

Naked Eye ◽

Cost Effective Approach ◽

Affinity Interaction

Pollen grain was explored as a new carrier for enzyme immobilization. After being modified with boric acid-functionalized titania, the pollen grain was able to covalently immobilize glycosylated enzymes by boronate affinity interaction under very mild experimental conditions (e.g., pH 7.0, ambient temperature and free of organic solvent). The glucose oxidase and horse radish peroxidase-immobilized pollen grain became a bienzyme system. The pollen grain also worked as an indicator of the cascade reaction by changing its color. A rapid, simple and cost-effective approach for the visual detection of glucose was then developed. When the glucose concentration exceeded 0.5 mM, the color change was observable by the naked eye. The assay of glucose in body fluid samples exhibited its great potential for practical application.

Download Full-text

Diagnosis of Onychomycosis: From Conventional Techniques and Dermoscopy to Artificial Intelligence

Frontiers in Medicine ◽

10.3389/fmed.2021.637216 ◽

2021 ◽

Vol 8 ◽

Author(s):

Sophie Soyeon Lim ◽

Jungyoon Ohn ◽

Je-Ho Mun

Keyword(s):

Artificial Intelligence ◽

Confocal Microscopy ◽

Cost Effective ◽

Diagnostic Techniques ◽

Fungal Species ◽

Accurate Diagnosis ◽

Reflectance Confocal Microscopy ◽

Diagnostic Tools ◽

Fungal Culture ◽

Microscopic Features

Onychomycosis is a common fungal nail infection. Accurate diagnosis is critical as onychomycosis is transmissible between humans and impacts patients' quality of life. Combining clinical examination with mycological testing ensures accurate diagnosis. Conventional diagnostic techniques, including potassium hydroxide testing, fungal culture and histopathology of nail clippings, detect fungal species within nails. New diagnostic tools have been developed recently which either improve detection of onychomycosis clinically, including dermoscopy, reflectance confocal microscopy and artificial intelligence, or mycologically, such as molecular assays. Dermoscopy is cost-effective and non-invasive, allowing clinicians to discern microscopic features of onychomycosis and fungal melanonychia. Reflectance confocal microscopy enables clinicians to observe bright filamentous septate hyphae at near histologic resolution by the bedside. Artificial intelligence may prompt patients to seek further assessment for nails that are suspicious for onychomycosis. This review evaluates the current landscape of diagnostic techniques for onychomycosis.

Download Full-text

Green Synthesis and Spectroscopic Studies of Ag-rGO Nanocomposites for Highly Selective Mercury (II) Sensing

Nanoscience &Nanotechnology-Asia ◽

10.2174/2210681207666170705143629 ◽

2018 ◽

Vol 9 (1) ◽

pp. 101-108 ◽

Cited By ~ 1

Author(s):

Shubhangi J. Mane-Gavade ◽

Sandip R. Sabale ◽

Xiao-Ying Yu ◽

Gurunath H. Nikam ◽

Bhaskar V. Tamhankar

Keyword(s):

Green Synthesis ◽

Color Change ◽

Limit Of Detection ◽

Aqueous Media ◽

Suitable Condition ◽

Cost Effective ◽

Spectroscopic Studies ◽

Calibration Plot ◽

First Time

Introduction: Herein we report the green synthesis and characterization of silverreduced graphene oxide nanocomposites (Ag-rGO) using Acacia nilotica gum for the first time. Experimental: We demonstrate the Hg2+ ions sensing ability of the Ag-rGO nanocomposites form aqueous medium. The developed colorimetric sensor method is simple, fast and selective for the detection of Hg2+ ions in aqueous media in presence of other associated ions. A significant color change was noticed with naked eye upon Hg2+ addition. The color change was not observed for cations including Sr2+, Ni2+, Cd2+, Pb2+, Mg2+, Ca2+, Fe2+, Ba2+ and Mn2+indicating that only Hg2+ shows a strong interaction with Ag-rGO nanocomposites. Under the most suitable condition, the calibration plot (A0-A) against concentration of Hg2+ was linear in the range of 0.1-1.0 ppm with a correlation coefficient (R2) value 0.9998. Results & Conclusion The concentration of Hg2+ was quantitatively determined with the Limit of Detection (LOD) of 0.85 ppm. Also, this method shows excellent selectivity towards Hg2+ over nine other cations tested. Moreover, the method offers a new cost effective, rapid and simple approach for the detection of Hg2+ in water samples.

Download Full-text

Tick-borne zoonoses and commonly used diagnostic methods in human and veterinary medicine

Parasitology Research ◽

10.1007/s00436-020-07033-3 ◽

2021 ◽

Author(s):

Andrea Springer ◽

Antje Glass ◽

Julia Probst ◽

Christina Strube

Keyword(s):

Veterinary Medicine ◽

Diagnostic Tests ◽

One Health ◽

Animal Health ◽

Diagnostic Techniques ◽

Diagnostic Methods ◽

Diagnostic Tools ◽

Zoonotic Pathogens ◽

Health Concept ◽

The One

AbstractAround the world, human health and animal health are closely linked in terms of the One Health concept by ticks acting as vectors for zoonotic pathogens. Animals do not only maintain tick cycles but can either be clinically affected by the same tick-borne pathogens as humans and/or play a role as reservoirs or sentinel pathogen hosts. However, the relevance of different tick-borne diseases (TBDs) may vary in human vs. veterinary medicine, which is consequently reflected by the availability of human vs. veterinary diagnostic tests. Yet, as TBDs gain importance in both fields and rare zoonotic pathogens, such as Babesia spp., are increasingly identified as causes of human disease, a One Health approach regarding development of new diagnostic tools may lead to synergistic benefits. This review gives an overview on zoonotic protozoan, bacterial and viral tick-borne pathogens worldwide, discusses commonly used diagnostic techniques for TBDs, and compares commercial availability of diagnostic tests for humans vs. domestic animals, using Germany as an example, with the aim of highlighting existing gaps and opportunities for collaboration in a One Health framework.

Download Full-text

Infrared nanospectroscopy reveals the molecular interaction fingerprint of an aggregation inhibitor with single Aβ42 oligomers

Nature Communications ◽

10.1038/s41467-020-20782-0 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Francesco Simone Ruggeri ◽

Johnny Habchi ◽

Sean Chia ◽

Robert I. Horne ◽

Michele Vendruscolo ◽

...

Keyword(s):

Small Molecules ◽

Single Molecule ◽

Protein Misfolding ◽

Molecular Mechanisms ◽

Chemical Sensitivity ◽

Incomplete Knowledge ◽

Parkinson’S Diseases ◽

Aggregation Inhibitor ◽

Misfolding Diseases

AbstractSignificant efforts have been devoted in the last twenty years to developing compounds that can interfere with the aggregation pathways of proteins related to misfolding disorders, including Alzheimer’s and Parkinson’s diseases. However, no disease-modifying drug has become available for clinical use to date for these conditions. One of the main reasons for this failure is the incomplete knowledge of the molecular mechanisms underlying the process by which small molecules interact with protein aggregates and interfere with their aggregation pathways. Here, we leverage the single molecule morphological and chemical sensitivity of infrared nanospectroscopy to provide the first direct measurement of the structure and interaction between single Aβ42 oligomeric and fibrillar species and an aggregation inhibitor, bexarotene, which is able to prevent Aβ42 aggregation in vitro and reverses its neurotoxicity in cell and animal models of Alzheimer’s disease. Our results demonstrate that the carboxyl group of this compound interacts with Aβ42 aggregates through a single hydrogen bond. These results establish infrared nanospectroscopy as a powerful tool in structure-based drug discovery for protein misfolding diseases.

Download Full-text

Imaging Diagnosis of Right Ventricle Involvement in Chagas Cardiomyopathy

BioMed Research International ◽

10.1155/2017/3820191 ◽

2017 ◽

Vol 2017 ◽

pp. 1-14 ◽

Cited By ~ 3

Author(s):

Minna M. D. Romano ◽

Henrique T. Moreira ◽

André Schmidt ◽

Benedito Carlos Maciel ◽

José Antônio Marin-Neto

Keyword(s):

Right Ventricle ◽

Tissue Characterization ◽

Low Cost ◽

Diagnostic Techniques ◽

Diagnostic Tools ◽

Deformation Analysis ◽

Geometrical Shape ◽

Gold Standard Method ◽

Chagas Cardiomyopathy ◽

Health And Disease

Right ventricle (RV) is considered a neglected chamber in cardiology and knowledge about its role in cardiac function was mostly focused on ventricular interdependence. However, progress on the understanding of myocardium diseases primarily involving the RV led to a better comprehension of its role in health and disease. In Chagas disease (CD), there is direct evidence from both basic and clinical research of profound structural RV abnormalities. However, clinical detection of these abnormalities is hindered by technical limitations of imaging diagnostic tools. Echocardiography has been a widespread and low-cost option for the study of patients with CD but, when applied to the RV assessment, faces difficulties such as the absence of a geometrical shape to represent this cavity. More recently, the technique has evolved to a focused guided RV imaging and myocardial deformation analysis. Also, cardiac magnetic resonance (CMR) has been introduced as a gold standard method to evaluate RV cavity volumes. CMR advantages include precise quantitative analyses of both LV and RV volumes and its ability to perform myocardium tissue characterization to identify areas of scar and edema. Evolution of these cardiac diagnostic techniques opened a new path to explore the pathophysiology of RV dysfunction in CD.

Download Full-text

Visual detection of carbonate ions by inverse opal photonic crystal polymers in aqueous solution

Journal of Materials Chemistry C ◽

10.1039/c5tc02253c ◽

2015 ◽

Vol 3 (37) ◽

pp. 9524-9527 ◽

Cited By ~ 12

Author(s):

Lu Li ◽

Bin Zhao ◽

Yue Long ◽

Jin-Ming Gao ◽

Guoqiang Yang ◽

...

Keyword(s):

Aqueous Solution ◽

Photonic Crystal ◽

Polymer Films ◽

Visual Detection ◽

Color Change ◽

Ph Dependence ◽

Inverse Opal ◽

Carbonate Ions ◽

Crystal Polymer

This communication demonstrates a facile method to detect CO32− by naked eyes through color change based on the pH dependence of inverse opal photonic crystal polymer films.

Download Full-text