Lateral flow assay for carbohydrate antigen 19–9 in whole blood by using magnetized carbon nanotubes

Abstract

The authors describe a rapid, low-cost and sensitive approach for the determination of carbohydrate antigen 19-9 (CA 19-9) in whole blood by using magnetized carbon nanotube (MCNT) and lateral flow strip biosensor (LFSB). MCNTs were synthesized by depositing magnetite (Fe3O4) nanoparticles on multiwalled carbon nanotube (CNT) via co-precipitation of ferric and ferrous ions within a dispersion of shortened multiwalled CNTs. Antibody against CA 19-9 (Ab1) was covalently immobilized on the MCNTs and were used to capture CA 19-9 in blood. After magnetic separation, the formed MCNT-Ab1-CA 19-9 complexes are applied to the LFSB, in which a capture antibody (Ab2) and a secondary antibody (Ab3) are immobilized on the test zone and control zone of the LFSB, respectively. The captured MCNTs on the test zone and control zone are producing characteristic brown bands, and this enables CA 19-9 to be visually detected. Quantitation is accomplished by reading the intensities of the bands with a portable strip reader. Under optimized conditions, the assay has a detection limit as low as 30 U⋅mL−1 of CA19-9 in blood. This is below the cutoff value (37 U mL−1) of CA 19-9. The assay duration for blood samples is 35 min. In our perception, the assay represents a rapid and low-cost tool for rapid determination of CA19-9 in blood that holds promise for clinical applications, particularly in limited resource settings.

Antibacterial Activity of Fe3O4/Cu Nanocomposite: Green Synthesis Using Carum carvi L. Seeds Aqueous Extract

“…In the last decade, magnetite nanoparticles (Fe 3 O 4 NPs) have attracted much attention due to biocompatibility and magnetic properties, and many studies have been done on their application . Thus, Fe 3 O 4 NPs with crystalline phase seem to be an important nanomaterial (NM) for many biomedical uses including cell therapy as cell labeling, as a tool for separate and purify cell populations, tissue repair, targeting, drug delivery, MRI, hyperthermia,, photocatalysis, ferro‐fluid technology, magneto‐caloric refrigeration, pigment, magnetic storage, magnetic ink printing, microwave absorption, biosensors, bioseparation and immune magnetic array …”

Magnetized Carbon Nanotube Based Lateral Flow Immunoassay for Visual Detection of Complement Factor B

“…The CNTs collected after the final washing step were dispersed in 10 mL of water for further use. A co-precipitation method was used to prepare MCNTs [20]. In brief, 0.015 mmol FeCl 3 ·6H 2 O and 0.075 mmol FeCl 2 ·4H 2 O were mixed with 10 mL of shortened CNTs.…”

“…We prepared MCNT-Ab 1 and MCNT-Ab 2 conjugates with the reported methods [20]. 0.25 mL of MCNTs was spun down and mixed with 4.8 mg EDC and 2.7 mg sulfo-NHS in 0.5 mL MES buffer (0.1 M, pH 4.7).…”

“…In our previous work, we have devised magnetized carbon nanotube (MCNT)-based LFIs for determination of IgG and CA 19-9 in human blood [19,20]. Herein, a MCNT-based LFI for the fast and efficient detection of CFB in blood is developed.…”

Commercially available rapid diagnostic tests for the detection of high priority pathogens: status and challenges

“…The fabrication of most LFIs involves combining several materials, e.g., paper membranes, Au nanoparticles, antibodies, and antigens. Despite the overwhelming number of scientific reports and discussion of how the integration of LFIs with novel materials with intrinsic properties, such as carbon nanotubes, 149,150 III-V nanostructures, 151,152 and graphene, [153][154][155] will disrupt the diagnostic market, only a few materials and techniques have made the transition from the lab bench to commercialization for disease detection during outbreaks. More efficient interactions between researchers in fields like immunology, biochemistry, materials science, diagnostics, and regulating bodies are required to accelerate the development of robust RDTs that fulfill the criteria listed by the WHO for the ideal rapid detection device during disease outbreaks, 13 Fig.…”