Point-of-care vertical flow immunoassay system for ultra-sensitive multiplex biothreat-agent detection in biological fluids.

This paper presents simple, fast, and sensitive detection of multiple biothreat agents by paper-based vertical flow colorimetric sandwich immunoassay for detection of Yersinia pestis (LcrV and F1) and Francisella tularensis (lipopolysaccharide; LPS) antigens using a vertical flow immunoassay (VFI) prototype with portable syringe pump and a new membrane holder. The capture antibody (cAb) printing onto nitrocellulose membrane and gold-labelled detection antibody (dAb) were optimized to enhance the assay sensitivity and specificity. Even though the paper pore size was relaxed from previous 0.

Optimization of an Antibody Microarray Printing Process Using a Designed Experiment.

Antibody microarrays have proven useful in immunoassay-based point-of-care diagnostics for infectious diseases. Noncontact piezoelectric inkjet printing has advantages to print antibody microarrays on nitrocellulose substrates for this application due to its compatibility with sensitive solutions and substrates, simple droplet control, and potential for high-capacity printing. However, there remain real-world challenges in printing such microarrays, which motivated this study.

Critical Comparison between Large and Mini Vertical Flow Immunoassay Platforms for Detection.

is a Gram-negative bacterium that is the causative agent of plague and is widely recognized as a potential biological weapon. Due to the high fatality rate of plague when diagnosis is delayed, the development of rapid, sensitive, specific, and cost-effective methods is needed for its diagnosis. The low calcium response V (LcrV) protein has been identified as a potential microbial biomarker for the diagnosis of plague.

Characterization and Optimization of Isotachophoresis Parameters for Pacific Blue Succinimidyl Ester Dye on a PDMS Microfluidic Chip.

Isotachophoresis (ITP) for Pacific Blue (PB) dye using a polydimethylsiloxane (PDMS) microfluidic chip is developed and characterized by determining the types and concentrations of electrolytes, the ITP duration, and the electric field density. Among candidate buffers for the trailing electrolyte (TE) and leading electrolyte (LE), 40 mM borate buffer (pH 9) and 200 mM trisaminomethane hydrochloride (Tris-HCl) (pH 8) were selected to obtain the maximum preconcentration and resolution of the PB bands, respectively. With the selected TE and LE buffers, further optimization was performed to determine the electric field (EF) density and the ITP duration.

Smartphone coupled handheld array reader for real-time toxic gas detection.

Smartphones and related accessories are rapidly expanding their applications in various fields. Herein we developed a smartphone coupled handheld array reader with the integration of complementary metal oxide (CMOS) image sensor for detecting various toxic gases by colorimetric monitoring approach. In this study, toxic gases such as hydrogen fluoride (HF), chlorine (Cl), ammonia (NH), and formaldehyde (CHO) were detected using titanium nanoparticles (TiO NPs) blended poly (vinyl alcohol) (PVA) hydrogel test strips, which were patterned with chemically responsive dyes.

A Chemically Patterned Microfluidic Paper-based Analytical Device (C-µPAD) for Point-of-Care Diagnostics.

A chemically patterned microfluidic paper-based analytical device (C-µPAD) is developed to create fluidic networks by forming hydrophobic barriers using chemical vapor deposition (CVD) of trichlorosilane (TCS) on a chromatography paper. By controlling temperature, pattern size, and CVD duration, optimal conditions were determined by characterizing hydrophobicity, spreading patterns, and flow behavior on various sized fluidic patterns. With these optimal conditions, we demonstrated glucose assay, immunoassay, and heavy metal detection on well-spot C-µPAD and lateral flow C-µPAD.

Recent analytical approaches to detect exhaled breath ammonia with special reference to renal patients.

The ammonia odor from the exhaled breath of renal patients is associated with high levels of blood urea nitrogen. Typically, in the liver, ammonia and ammonium ions are converted into urea through the urea cycle. In the case of renal dysfunction, urea is unable to be removed and that causes a buildup of excessive ammonia.

Real-time DNA Amplification and Detection System Based on a CMOS Image Sensor.

In the present study, we developed a polypropylene well-integrated complementary metal oxide semiconductor (CMOS) platform to perform the loop mediated isothermal amplification (LAMP) technique for real-time DNA amplification and detection simultaneously. An amplification-coupled detection system directly measures the photon number changes based on the generation of magnesium pyrophosphate and color changes. The photon number decreases during the amplification process.

Whole blood glucose analysis based on smartphone camera module.

Complementary metal oxide semiconductor (CMOS) image sensors have received great attention for their high efficiency in biological applications. The present work describes a CMOS image sensor-based whole blood glucose monitoring system through a point-of-care (POC) approach. A simple poly-ethylene terephthalate (PET) chip was developed to carry out the enzyme kinetic reaction at various concentrations (110–586 mg∕dL) of mouse blood glucose.

Label Free Quantitative Immunoassay for Hepatitis B.

Complementary metal oxide semiconductor (CMOS) technology has already been proven in molecular diagnostics. The present research proved that CMOS image sensor based immunodetection is a suitable diagnostic system for hepatitis B virus antigen (HBV-Ag)-antibody (Ab) interaction. The Ag-Ab was interacted on InNP substrate which was analyzed by a CMOS image sensor by photon number variation.

An ultrasensitive method of real time pH monitoring with complementary metal oxide semiconductor image sensor.

CMOS sensors are becoming a powerful tool in the biological and chemical field. In this work, we introduce a new approach on quantifying various pH solutions with a CMOS image sensor. The CMOS image sensor based pH measurement produces high-accuracy analysis, making it a truly portable and user friendly system.

CMOS image sensors as an efficient platform for glucose monitoring.

Complementary metal oxide semiconductor (CMOS) image sensors have been used previously in the analysis of biological samples. In the present study, a CMOS image sensor was used to monitor the concentration of oxidized mouse plasma glucose (86-322 mg dL(-1)) based on photon count variation. Measurement of the concentration of oxidized glucose was dependent on changes in color intensity; color intensity increased with increasing glucose concentration.

CMOS image sensor-based immunodetection by refractive-index change.

A complementary metal oxide semiconductor (CMOS) image sensor is an intriguing technology for the development of a novel biosensor. Indeed, the CMOS image sensor mechanism concerning the detection of the antigen-antibody (Ag-Ab) interaction at the nanoscale has been ambiguous so far. To understand the mechanism, more extensive research has been necessary to achieve point-of-care diagnostic devices.

Toward CMOS image sensor based glucose monitoring.

Complementary metal oxide semiconductor (CMOS) image sensor is a powerful tool for biosensing applications. In this present study, CMOS image sensor has been exploited for detecting glucose levels by simple photon count variation with high sensitivity. Various concentrations of glucose (100 mg dL(-1) to 1000 mg dL(-1)) were added onto a simple poly-dimethylsiloxane (PDMS) chip and the oxidation of glucose was catalyzed with the aid of an enzymatic reaction.

A CMOS image sensor to recognize the cardiovascular disease markers troponin I and C-reactive protein.

A complementary metal oxide semiconductor (CMOS) image sensor was utilized to detect the interaction of cardiovascular disease markers, troponin I and C-reactive protein. Each marker with its respective antibodies was adsorbed to an indium nanoparticle (InNP)-coated glass substrate. Dielectric layers of antigens and antibodies bound onto and interacted on conducting InNPs.

Fish-on-a-chip: a sensitive detection microfluidic system for Alzheimer's disease.

Microfluidics has become an important tool in diagnosing many diseases, including neurological and genetic disorders. Alzheimer's disease (AD) is a neurodegenerative disease that irreversibly and progressively destroys memory, language ability, and thinking skills. Commonly, detection of AD is expensive and complex.