Modern Trends in Imaging VIII: Lensfree Computational Microscopy Tools for Cell and Tissue Imaging at the Point-of-Care and in Low-Resource Settings

The recent revolution in digital technologies and information processing methods present important opportunities to transform the way optical imaging is performed, particularly toward improving the throughput of microscopes while at the same time reducing their relative cost and complexity. Lensfree computational microscopy is rapidly emerging toward this end, and by discarding lenses and other bulky optical components of conventional imaging systems, and relying on digital computation instead, it can achieve both reflection and transmission mode microscopy over a large field-of-view within compact, cost-effective and mechanically robust architectures. Such high throughput and miniaturized imaging devices can provide a complementary toolset for telemedicine applications and point-of-care diagnostics by facilitating complex and critical tasks such as cytometry and microscopic analysis of e.g., blood smears, Pap tests and tissue samples. In this article, the basics of these lensfree microscopy modalities will be reviewed, and their clinically relevant applications will be discussed.

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A Disposable Paper-Based Electrochemical Sensor Made of Pencil Graphite and Its Modification with Au for Detection of Glucose in Alkaline Solutions

10.26434/chemrxiv.12102975.v2 ◽

2020 ◽

Author(s):

Mustafa Sen

Keyword(s):

Environmental Monitoring ◽

Electrochemical Sensor ◽

Point Of Care ◽

Low Cost ◽

Cost Effective ◽

Alkaline Solutions ◽

Glucose Detection ◽

Electrochemical Modification ◽

Point Of Care Diagnostics

Paper-based sensors have great potential to be used in a variety of fields ranging from environmental monitoring to clinical and point-of-care diagnostics. These sensors are disposable, cost effective, flexible and easy to use. The aim of this study was to fabricate a low cost, disposable, reliable and easy to use paper-based electrochemical sensor and its electrochemical modification with nanostructured Au for glucose detection in alkaline solutions.

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Toward spectrometerless instant Raman identification with tailored metasurfaces-powered guided-mode resonances (GMR) filters

Nanophotonics ◽

10.1515/nanoph-2021-0444 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Mohamed A. Mousa ◽

Nadia H. Rafat ◽

Amr A. E. Saleh

Keyword(s):

Point Of Care ◽

Cost Effective ◽

Transmission Efficiency ◽

Guided Mode ◽

Point Of Care Diagnostics ◽

Identification Approach ◽

Pharmaceutical Industries ◽

Guided Mode Resonance ◽

New Generation

Abstract Raman identification is an instrumental tool with a broad range of applications, yet current spectroscopy approaches fall short in facilitating practical and scalable Raman identification platforms. In this work, we introduce a spectrometerless Raman identification approach that utilizes guided-mode resonance filters. Unlike arrayed narrowband-filters spectrometer, we tailor the transmission characteristics of each filter to match the Raman signature of a given target. Hence, instantaneous Raman identification could be directly achieved at the hardware level with no spectral data post-processing. The filters consist of a metasurface grating encapsulated between two identical distributed Bragg reflectors and are characterized by transmission peaks line-widths narrower than 0.01 nm and transmission efficiency exceeding 98%. We develop a rigorous design methodology to customize the filters’ characteristics such that the maximum optical transmission through a given filter is only attained when exposed to the Raman scattering from its matched target. To illustrate the potential of our approach, we theoretically investigate the identification of four different saccharides as well as the classification of two antibiotic-susceptible and resistant strains of Staphylococcus aureus. We show that our proposed approach can accurately identify these targets. Our work lays the foundation for a new-generation of scalable, compact, and cost-effective instant Raman identification platforms that can be adopted in countless applications from wearables and point-of-care diagnostics to in-line quality control in food and pharmaceutical industries.

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Cost-Effective Flexible CSRR-Based Sensor for Noninvasive Measurement of Permittivity of Biomaterials

Engineering Proceedings ◽

10.3390/ecsa-8-11303 ◽

2021 ◽

Vol 10 (1) ◽

pp. 26

Author(s):

Faezeh Shanehsazzadeh ◽

Nafise Azizi ◽

Hosna Kazerooni Haghighat ◽

Fatemeh Mashayekhi ◽

Mehdi Fardmanesh

Keyword(s):

Ring Resonator ◽

Point Of Care ◽

Cost Effective ◽

Split Ring Resonator ◽

Point Of Care Testing ◽

Split Ring ◽

Tissue Samples ◽

Complementary Split Ring Resonator ◽

Microwave Sensor ◽

Wide Range

A novel, cost-effective, flexible microwave sensor is proposed to facilitate point-of-care testing (POCT) methods for medical diagnosis. The sensor is based on the complementary split-ring resonator (CSRR) to accurately measure the permittivity of biomaterials over a wide range of frequencies. This ability can be used to characterize various materials under test (MUT) such as blood, saliva, tissue samples, etc. The flexibility of the proposed sensor means that it can be used when the accessibility of the sample has technical difficulties, such as on curved surfaces. Firstly, the optimized structure and coupling to the readout transmission line are evaluated using finite element method (FEM) simulations. Then, the prototype of the optimized structure is fabricated on a thin polydimethylsiloxane (PDMS) substrate as a biocompatible economical polymer, and aluminium is carefully chosen for the fabrication of CSRR and readout parts. The proposed flexible sensor is tested and compared to conventional rigid CSRR sensors. The proposed structure withstood the different bending positions well, and also showed an improvement in the results for curved MUT.

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A novel split mode TFBAR device for quantitative measurements of prostate specific antigen in a small sample of whole blood

Nanoscale ◽

10.1039/d0nr00416b ◽

2020 ◽

Vol 12 (17) ◽

pp. 9647-9652

Author(s):

Ewelina Wajs ◽

Girish Rughoobur ◽

Keith Burling ◽

Anne George ◽

Andrew J. Flewitt ◽

...

Keyword(s):

Prostate Specific Antigen ◽

Whole Blood ◽

Point Of Care ◽

Effective Means ◽

Specific Antigen ◽

Cost Effective ◽

Small Sample ◽

Quantitative Measurements ◽

Point Of Care Diagnostics ◽

Split Mode

TFBAR technology demonstrates a cost-effective means for point-of-care diagnostics and monitoring of PSA.

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Reusable Surface Molecular Imprint Biosensors Aided by Naturally Occurring Surface Roughness Indices for Point-of-Care Diagnostics

MRS Advances ◽

10.1557/adv.2019.138 ◽

2019 ◽

Vol 4 (22) ◽

pp. 1299-1308 ◽

Cited By ~ 1

Author(s):

Yehoshua Auerbach ◽

Rebecca Isseroff ◽

Nicholas Clayton ◽

Miguel Hulyalkar ◽

Andrew Todt ◽

...

Keyword(s):

Real Time ◽

Molecular Imprinting ◽

Point Of Care ◽

High Sensitivity ◽

Cost Effective ◽

Stem Cell Differentiation ◽

Diverse Range ◽

Point Of Care Diagnostics ◽

Molecular Imprint ◽

Detection Of Biomarkers

ABSTRACTWe have shown that molecular imprinting (MI) technology can be used to produce sensitive, robust, cost-effective biosensing systems with a real-time electrochemical readout that can be utilized for point of care diagnostics. Real time detection of biomarkers is essential when rapid, critical decisions need to be made, such as in situations where public health is threatened. Our biosensor has high sensitivity compared to standard methods like ELISA, and results are obtained within minutes, using inexpensive, accessible potentiometric readout technology. These biosensors utilize surface molecular imprinting of a self-assembling monolayer of hydroxy-terminated alkanethiol chains which form a crystalline ‘lock-and-key’ structure around a target analyte, allowing the sensors to detect and differentiate between bio-macromolecules of similar size and shape with high selectivity and sensitivity. The sensors are extremely versatile and able to detect a diverse range of molecules of varied chemical composition and structure. To fully exploit the sensors’ advantages, especially in remote, economically disadvantaged areas, it is important to quantify their durability and reusability. Biosensor chips were created to test the viability of hemoglobin detection and to evaluate the potential for sensor reusability when washed after detection testing. The successful readsorption of hemoglobin even after washing, accompanied by cyclic voltammetry data indicating the preservation of the SAM, indicate that these biosensors are reusable, significantly augmenting the device’s value. Potential applications include the analysis of complex chemical and biological processes such as stem cell differentiation and on-the-spot detection of diseases such as Zika.

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A Sensitive, Rapid, and Portable CasRx-based Diagnostic Assay for SARS-CoV-2

10.1101/2020.10.14.20212795 ◽

2020 ◽

Author(s):

Daniel J Brogan ◽

Duverney Chaverra-Rodriguez ◽

Calvin P Lin ◽

Andrea L Smidler ◽

Ting Yang ◽

...

Keyword(s):

Public Health ◽

Nucleic Acid ◽

Point Of Care ◽

Cost Effective ◽

Molecular Diagnostic ◽

Emerging Pathogens ◽

Public Health Importance ◽

Point Of Care Diagnostics ◽

Effective Diagnosis ◽

Critical Public Health

AbstractSince its first emergence from China in late 2019, the SARS-CoV-2 virus has spread globally despite unprecedented containment efforts, resulting in a catastrophic worldwide pandemic. Successful identification and isolation of infected individuals can drastically curtail virus spread and limit outbreaks. However, during the early stages of global transmission, point-of-care diagnostics were largely unavailable and continue to remain difficult to procure, greatly inhibiting public health efforts to mitigate spread. Furthermore, the most prevalent testing kits rely on reagent- and time-intensive protocols to detect viral RNA, preventing rapid and cost-effective diagnosis. Therefore the development of an extensive toolkit for point-of-care diagnostics that is expeditiously adaptable to new emerging pathogens is of critical public health importance. Recently, a number of novel CRISPR-based diagnostics have been developed to detect COVID-19. Herein, we outline the development of a CRISPR-based nucleic acid molecular diagnostic utilizing a Cas13d ribonuclease derived from Ruminococcus flavefaciens (CasRx) to detect SARS-CoV-2, an approach we term SENSR (Sensitive Enzymatic Nucleic-acid Sequence Reporter). We demonstrate SENSR robustly detects SARS-CoV-2 sequences in both synthetic and patient-derived samples by lateral flow and fluorescence, thus expanding the available point-of-care diagnostics to combat current and future pandemics.

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Eco-Friendly Synthesis of SnO2-Cu Nanocomposites and Evaluation of Their Peroxidase Mimetic Activity

Nanomaterials ◽

10.3390/nano11071798 ◽

2021 ◽

Vol 11 (7) ◽

pp. 1798

Author(s):

Ravi Mani Tripathi ◽

Sang J. Chung

Keyword(s):

Ph Value ◽

Point Of Care ◽

Low Cost ◽

Colorimetric Detection ◽

Cost Effective ◽

Promising Alternative ◽

Enzyme Mimetic ◽

Peroxidase Mimetic ◽

Point Of Care Diagnostics ◽

Cost Effective Method

The enzyme mimetic activity of nanomaterials has been applied in colorimetric assays and point-of-care diagnostics. Several nanomaterials have been exploited for their peroxidase mimetic activity toward 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of hydrogen peroxide. However, an efficient nanomaterial for the rapid and strong oxidation of TMB remains a strategic challenge. Therefore, in this study, we developed copper-loaded tin oxide (SnO2-Cu) nanocomposites that rapidly oxidize TMB. These nanocomposites have strong absorption at 650 nm and can be used for highly sensitive colorimetric detection. An environmentally friendly (green), rapid, easy, and cost-effective method was developed for the synthesis of these nanocomposites, which were characterized using ultraviolet-visible, energy-dispersive X-ray, and Fourier-transform infrared spectroscopy, as well as scanning electron microscopy. This is the first green synthesis of SnO2-Cu nanocomposites. Their enzyme mimetic activity, which was first studied here, was found to be strongly dependent on the temperature and pH value of the solution. The synthesized nanocomposites have the advantages of low cost, high stability, and ease of preparation for enzyme mimetic applications. Hence, SnO2-Cu nanocomposites are a promising alternative to peroxidase enzymes in colorimetric point-of-care diagnostics.

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Time for a change: addressing R&D and commercialization challenges for antibacterials

Philosophical Transactions of the Royal Society B Biological Sciences ◽

10.1098/rstb.2014.0086 ◽

2015 ◽

Vol 370 (1670) ◽

pp. 20140086 ◽

Cited By ~ 43

Author(s):

David J. Payne ◽

Linda Federici Miller ◽

David Findlay ◽

James Anderson ◽

Lynn Marks

Keyword(s):

Antibacterial Agents ◽

Point Of Care ◽

Cost Effective ◽

Pharmaceutical Companies ◽

Therapeutic Area ◽

Contributing Factors ◽

Point Of Care Diagnostics ◽

Global Harmonization ◽

The Right ◽

Perfect Storm

The antibacterial therapeutic area has been described as the perfect storm. Resistance is increasing to the point that our hospitals encounter patients infected with untreatable pathogens, the overall industry pipeline is described as dry and most multinational pharmaceutical companies have withdrawn from the area. Major contributing factors to the declining antibacterial industry pipeline include scientific challenges, clinical/regulatory hurdles and low return on investment. This paper examines these challenges and proposes approaches to address them. There is a need for a broader scientific agenda to explore new approaches to discover and develop antibacterial agents. Additionally, ideas of how industry and academia could be better integrated will be presented. While promising progress in the regulatory environment has been made, more streamlined regulatory paths are still required and the solutions will lie in global harmonization and clearly defined guidance. Creating the right incentives for antibacterial research and development is critical and a new commercial model for antibacterial agents will be proposed. One key solution to help resolve both the problem of antimicrobial resistance (AMR) and lack of new drug development are rapid, cost-effective, accurate point of care diagnostics that will transform antibacterial prescribing and enable more cost-effective and efficient antibacterial clinical trials. The challenges of AMR are too great for any one group to resolve and success will require leadership and partnerships among academia, industry and governments globally.

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A Disposable Paper-Based Electrochemical Sensor Made of Pencil Graphite and Its Modification with Au for Detection of Glucose in Alkaline Solutions

10.26434/chemrxiv.12102975.v1 ◽

2020 ◽

Author(s):

Mustafa Sen

Keyword(s):

Environmental Monitoring ◽

Electrochemical Sensor ◽

Point Of Care ◽

Low Cost ◽

Cost Effective ◽

Alkaline Solutions ◽

Glucose Detection ◽

Electrochemical Modification ◽

Point Of Care Diagnostics

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Capillary-Driven Flow Microfluidics Combined with Smartphone Detection: An Emerging Tool for Point-of-Care Diagnostics

Diagnostics ◽

10.3390/diagnostics10080509 ◽

2020 ◽

Vol 10 (8) ◽

pp. 509

Author(s):

Sammer-ul Hassan ◽

Aamira Tariq ◽

Zobia Noreen ◽

Ahmed Donia ◽

Syed Z. J. Zaidi ◽

...

Keyword(s):

Scientific Community ◽

Point Of Care ◽

Cost Effective ◽

Healthcare Systems ◽

Clinical Settings ◽

Internal Wall ◽

Point Of Care Diagnostics ◽

The World ◽

Flow Devices ◽

Near Patient Testing

Point-of-care (POC) or near-patient testing allows clinicians to accurately achieve real-time diagnostic results performed at or near to the patient site. The outlook of POC devices is to provide quicker analyses that can lead to well-informed clinical decisions and hence improve the health of patients at the point-of-need. Microfluidics plays an important role in the development of POC devices. However, requirements of handling expertise, pumping systems and complex fluidic controls make the technology unaffordable to the current healthcare systems in the world. In recent years, capillary-driven flow microfluidics has emerged as an attractive microfluidic-based technology to overcome these limitations by offering robust, cost-effective and simple-to-operate devices. The internal wall of the microchannels can be pre-coated with reagents, and by merely dipping the device into the patient sample, the sample can be loaded into the microchannel driven by capillary forces and can be detected via handheld or smartphone-based detectors. The capabilities of capillary-driven flow devices have not been fully exploited in developing POC diagnostics, especially for antimicrobial resistance studies in clinical settings. The purpose of this review is to open up this field of microfluidics to the ever-expanding microfluidic-based scientific community.

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