A novel experimental methodology based on the unique characteristics of chitosan-branched ferrocene (CS-Fc) and gold nanoparticles (Au NPs) was developed to design a label-free amperometric immunosensor for the sensitive detection of hepatitis B surface antigen (HBsAg) as a model protein. The controllable electrodeposition of CS-Fc solution formed a three-dimensional robust film with good biocompatibility and large surface area for the assembly of Au NPs and further immobilization of hepatitis B surface antibody (HBsAb) on an electrode. The morphologies and electrochemistry of the formed nanocomposite biofilm were investigated by using scanning electron microscopy and electrochemical techniques including cyclic voltammetry and electrochemical impedance spectroscopy, respectively. The HBsAg concentration was measured through the decrease of amperometric responses in the corresponding specific binding of antigen and antibody. The decreased differential pulse voltametric values were proportional to the HBsAg concentration in the range of 0.05-305ngmL(-1) with a detection limit 0.016ng. This would provide an approach for the application of mediator in immunoassays.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bios.2009.08.048DOI Listing

Publication Analysis

Top Keywords

label-free amperometric
8
amperometric immunosensor
8
hepatitis surface
8
hbsag concentration
8
immunosensor based
4
based biocompatible
4
biocompatible conductive
4
conductive redox
4
redox chitosan-ferrocene/gold
4
chitosan-ferrocene/gold nanoparticles
4

Similar Publications

Interleukin-6 (IL6) is a cytokine mainly involved in inflammatory processes associated with various diseases, from rheumatoid arthritis and pathogen-caused infections to cancer, where malignant cells exhibit high proliferation and overexpression of cytokines, including IL6. Furthermore, IL6 plays a fundamental role in detecting and differentiating tumor cells, including colorectal cancer (CRC) cells. Therefore, given its range of biological activities and pathological role, IL6 determination has been claimed for the diagnosis/prognosis of immune-mediated diseases.

View Article and Find Full Text PDF

Molecularly imprinted composite-based biosensor for the determination of SARS-CoV-2 nucleocapsid protein.

Biosens Bioelectron

May 2024

Department of Nanotechnology, State Research Institute Center for Physical and Technological Sciences (FTMC), Sauletekio Ave. 3, Vilnius, LT-10257, Lithuania; Department of Physical Chemistry, Institute of Chemistry, Faculty of Chemistry and Geosciences, Vilnius University (VU), Naugarduko Str. 24, 03225 Vilnius, LT-03225, Lithuania. Electronic address:

This article aims to present a comparative study of three polypyrrole-based molecularly imprinted polymer (MIP) systems for the detection of the recombinant severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid protein (rN). The rN is known for its relatively low propensity to mutate compared to other SARS-CoV-2 antigens. The aforementioned systems include screen-printed carbon electrodes (SPCE) modified with gold nanostructures (MIP1), platinum nanostructures (MIP2), and the unmodified SPCE (MIP3), which was used for control.

View Article and Find Full Text PDF
Article Synopsis
  • Human milk is rich in carbohydrates, specifically human milk oligosaccharides (HMOs) and various types of glycans, but the specific profile of glycans had not been thoroughly studied until now.
  • This study employed label-free chromatography-mass spectrometry (LC-MS) to analyze the variation in glycan composition and concentration in 200 samples of Japanese human milk from mothers 1-2 months postpartum.
  • Findings showed that the presence of fucose linked to galactose affected the abundance of certain glycans and HMOs, with secretor mothers producing more of these compounds compared to nonsecretors, although the overall profile of glycans remained unchanged.
View Article and Find Full Text PDF

An electrochemical bioplatform involving screen-printed carbon electrodes modified with rGO/MoS/AgNPs nanocomposites, the covalent immobilization of the specific capture antibody, and label-free detection has been developed for the determination of Glial Fibrillary Acidic Protein (GFAP). The resulting immunosensor profits the benefits of the rGO high conductivity, the pseudo-peroxidase activity of MoS and the electrocatalytic effect provided by AgNPs for improving the reduction current responses of hydrogen peroxide at the electrode surface. GFAP is a biomarker of central nervous system injuries has been proposed for the detection and monitoring of neurological diseases as epilepsy, encephalitis, or multiple sclerosis.

View Article and Find Full Text PDF

Hybrid Functional Polymer-Enabled Multiplexed Chemosensor Patch for Wearable Adrenocortex Stress Profiling.

ACS Appl Mater Interfaces

November 2023

School of Electrical Engineering and Computer Science, Oregon State University, Corvallis, Oregon 97331, United States.

Measuring bioactive stress hormones, including cortisol and dehydroepiandrosterone (DHEA), allows for evaluating the hypothalamic-pituitary-adrenal (HPA) axis functioning, offering valuable insights into an individual's stress response through adrenocortex stress profiles (ASPs). Conventional methods for detecting steroid hormones involve sample collections and competitive immunoassays, which suffer from drawbacks such as time-consuming labeling and binding procedures, reliance on unstable biological receptors, and the need for sophisticated instruments. Here, we report a label-free and external redox reagent-free amperometric assay directly detecting sweat cortisol and DHEA levels on the skin.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!