Facile preparation of carbon nanotube-conducting polymer network for sensitive electrochemical immunoassay of Hepatitis B surface antigen in serum

Dias

J. Chem. Technol. Biotechnol.

et al. 2014

BACKGROUND: A sensitive nanostructured immunoelectrode based on poly(allylamine) (PAH) sandwich is developed for nonstructural 1 (NS1) of dengue virus. NS1 is a secretory protein abundant in the acute phase of disease associated to hemorrhagic fever. Anti-NS1 antibodies are immobilized on the electrode surface by a thin layer of PAH assembled on carboxylated carbon nanotubes (CNTs). PAH is cationic polymer acting as bi-functional agent to tightly attach CNTs to the electrode surface and anti-NS1 antibodies through their Fc terminal, avoiding random immobilization. Electrochemical responses of immunoassay are generated at a controlled potential by a reaction between H 2 O 2 and peroxidase enzyme conjugated to anti-NS1 antibodies.

Section: Resultsmentioning

confidence: 81%

Electrochemical detection of dengue virus NS1 protein with a poly(allylamine)/carbon nanotube layered immunoelectrode

Dias

J. Chem. Technol. Biotechnol.

et al. 2014

“…They also developed lab-on-a-chip using this CNT-ECL immunoassay to detect SEB [66,67]. Hu et al [68] reported an electrochemical immunosensor built on 3-D CNT-conducting polymer network for detection of hepatitis B surface antigen in human serum, reaching a detection limit of 0.01 ng/mL with a dynamic range of 5 orders of magnitude.…”

Section: Immunoassay Lab-on-a-chip With Electrochemical Detectionmentioning

confidence: 99%

Lab-on-a-Chip Pathogen Sensors for Food Safety

Yoon

Kim

2012

Sensors

165

There have been a number of cases of foodborne illness among humans that are caused by pathogens such as Escherichia coli O157:H7, Salmonella typhimurium, etc. The current practices to detect such pathogenic agents are cell culturing, immunoassays, or polymerase chain reactions (PCRs). These methods are essentially laboratory-based methods that are not at all real-time and thus unavailable for early-monitoring of such pathogens. They are also very difficult to implement in the field. Lab-on-a-chip biosensors, however, have a strong potential to be used in the field since they can be miniaturized and automated; they are also potentially fast and very sensitive. These lab-on-a-chip biosensors can detect pathogens in farms, packaging/processing facilities, delivery/distribution systems, and at the consumer level. There are still several issues to be resolved before applying these lab-on-a-chip sensors to field applications, including the pre-treatment of a sample, proper storage of reagents, full integration into a battery-powered system, and demonstration of very high sensitivity, which are addressed in this review article. Several different types of lab-on-a-chip biosensors, including immunoassay- and PCR-based, have been developed and tested for detecting foodborne pathogens. Their assay performance, including detection limit and assay time, are also summarized. Finally, the use of optical fibers or optical waveguide is discussed as a means to improve the portability and sensitivity of lab-on-a-chip pathogen sensors.

“…For instance, their huge accessible surface areas make them a promising representative for biomolecules binding [16]. Moreover, their electrical properties can improve the electrochemical performance and promote electron transfer between the electroactive species and electrode [17]. Therefore, they have been served as attractive candidates for biosensors.…”

Section: Introductionmentioning

confidence: 99%

Immunoassay for netrin 1 via a glassy carbon electrode modified with multi-walled carbon nanotubes, thionine and gold nanoparticles

Gao

et al. 2015

Microchim Acta

We describe a nanostructured immunosensor for the cardiovascular biomarker netrin 1. A glassy carbon electrode was consecutively modified with multi-walled carbon nanotubes (MWCNTs), nafion (to retain the MWCNTs), thionine-coated gold nanoparticles (Thi@AuNPs), and monoclonal antibodies against netrin 1. The modified electrode was characterized by transmission electron microscopy, cyclic voltammetry, differential pulse voltammetry, UV-visible spectrophotometry and X-ray diffraction. The presence of Thi@AuNPs warrants direct and convenient immobilization of the antibody. This immunoelectrode enables netrin 1 to be determined, best at a voltage of −300 mV (vs. SCE), with a limit of detection of 30 fg mL −1 (at an S/N ratio of 3) after a 50 min incubation time. The detection range extends from 0.09 to 1800 pg mL −1 . The method is simple, sensitive, specific and reproducible. We presume this stable and reproducible biosensor to be useful for the early detection of cardiovascular diseases.