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.2009.08.048 | DOI Listing |
Mikrochim Acta
October 2024
Max Planck Tandem Group in Nanobioengieneering, University of Antioquia, Complejo Ruta N, Calle 67 Nº 52-20, 050010, Medellín, Colombia.
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 PDFBiosens 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 PDFInt J Mol Sci
February 2024
Milk Science Research Institute, Megmilk Snow Brand Co., Ltd., 1-1-2 Minamidai, Kawagoe-shi 350-1165, Saitama, Japan.
Talanta
April 2024
Department of Analytical Chemistry, Faculty of Chemistry, University Complutense of Madrid, 28040, Madrid, Spain.
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 PDFACS 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 PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!