A novel electrochemical immunosensor for the detection of matrix metalloproteinase-3 (MMP-3), a cancer biomarker protein, based on vertically aligned single-wall carbon nanotube (SWCNT) arrays is presented. Detection was based on a sandwich immunoassay consisting of horseradish peroxidase (14-16 labels) conjugated to a secondary antibody and/or a polymer bead loaded with multi-enzyme labels. Pe...

A versatile immunosensor using CdTe quantum dots as electrochemical and fluorescent labels has been developed for sensitive protein detection. This sandwich-type sensor is fabricated on an indium tin oxide chip covered with a well-ordered gold nanoparticle monolayer. Gel imaging systems were successfully introduced to develop a novel high-efficient optical immunoassay, which could perform simul...

Scanning electrochemical microscopy (SECM) has been widely used for the electrochemical imaging of dynamic topographical and metabolic changes in alive adherent mammalian cells. However, extracting intracellular information by SECM is challenging, since it requires redox species to travel in and out the lipid cell membrane. Herein, we present cell fixation and permeabilization approaches as an ...

sayed by liquid chromatography, immunoassay, or capillary electrophoresis. The separation systems offer selective detection of analytes, but in many cases, the temporal resolution of the assay is not sufficient for continuous real-time monitoring of the microdialysate. These techniques are limited by the minimum sample volume required for practical sample handling and reliable measurements. The...

An amperometric electrochemical immunoassay specific for protein A-bearing Staphylococcus aureus was developed. The method was based on a sandwich immunosorbent assay and incorporated an enzyme amplification step, using a NAD-specific redox cycle generating NADH (C. H. Stanley, A. Johannsson, and C. H. Self, J. Immunol. Methods 83:89-95, 1985). Reduction of the mediator, ferricyanide, was depen...

Recent work has demonstrated nanopatterning of gold, using a Focussed Ion Beam, and similarly, nanotemplating gold, for direct protein attachment, useful for alternative sensing techniques. The impedance changes due to myoglobin capture by antimyoglobin immobilised on gold, have been measured, in a 3 electrode electrochemical cell. The impedance changes reach an end-point level after 15-20 minu...

There is an increasing interest in developing microfluidic bioreactors and organs-on-a-chip platforms combined with sensing capabilities for continual monitoring of cell-secreted biomarkers. Conventional approaches such as ELISA and mass spectroscopy cannot satisfy the needs of continual monitoring as they are labor-intensive and not easily integrable with low-volume bioreactors. This paper rep...

A novel electrochemical immunosensor using screen-printed carbon electrodes and functionalized magnetic particles was developed for the determination of cortisol. Anti-cortisol antibody was immobilized onto protein A-modified magnetic particles and a direct competitive immunoassay involving cortisol antigen labeled with alkaline phosphatase (AP) was employed. The resulting conjugate was trapped...

BACKGROUND The purpose of this study was to devise a novel electrochemical immunosensor for ultrasensitive detection of alfa-fetoprotein based on Fe(3)O(4)/Au nanoparticles as a carrier using a multienzyme amplification strategy. METHODS AND RESULTS Greatly enhanced sensitivity was achieved using bioconjugates containing horseradish peroxidase (HRP) and a secondary antibody (Ab(2)) linked to ...

background: improving the performance of hiv diagnosis assays is one of the most important ways to reduce hiv transmission. because of the high mutation rate of hiv, it is critical to use the conserved proteins to develop diagnostic immunoassay methods. because integrase is one of the most conserved proteins of hiv, it may be a good target for this purpose. in this paper cloning, purification a...