Search results for "Biosensing techniques"
showing 10 items of 96 documents
Equilibrium coverage fluctuations: a new approach to quantify reversible adsorption of proteins.
2005
Scrutiny of annexin A1 mediated membrane-membrane interaction by means of a thickness shear mode resonator and computer simulations.
2004
The dissipational quartz crystal microbalance (D-QCM) technology was applied to monitor the adsorption of vesicles to membrane-bound annexin A1 by simultaneously reading out the shifts in resonance frequency and dissipation. Solid-supported membranes (SSMs) composed of a chemisorbed octanethiol monolayer and a physisorbed 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine/1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoserine monolayer were immobilized on the gold electrode of a 5 MHz quartz plate. Adsorption and desorption of annexin A1 to the SSM was followed by means of the QCM technique. After nonbound annexin A1 was removed from solution, the second membrane binding was monitored by the D-QCM t…
Partially Reversible Adsorption of Annexin A1 on POPC/POPS Bilayers Investigated by QCM Measurements, SFM, and DMC Simulations
2005
The kinetics of annexin A1 binding to solid-supported lipid bilayers consisting of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC)/1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoserine (POPS; 4:1) has been investigated as a function of the calcium ion concentration in the bulk phase. Quartz crystal microbalance measurements in conjunction with scanning force microscopy, fluorescence microscopy, and computer simulations indicate that at a given Ca2+ concentration annexin A1 adsorbs irreversibly on membrane domains enriched in POPS. By contrast, annexin A1 adsorbs reversibly on the POPC-enriched phase, which is composed of single POPS molecules embedded within a POPC matrix. The overall are…
A thin layer-based amperometric enzyme immunoassay for the rapid and sensitive diagnosis of respiratory syncytial virus infections
2012
Abstract A simple electrochemical sandwich immunoassay involving a polystyrene microarray slide coated with monoclonal capture antibodies and carbon screen-printed sensors (SPS) was designed for the rapid diagnosis of respiratory syncytial virus (RSV). The detection of the antibody-antigen complex formation relied on the use of a horseradish peroxidase conjugate. Its chronoamperometric measurement detection was performed by confining a droplet of H 2 O 2 /3,3',5,5'-tetramethylbenzidine enzyme substrate/mediator solution within a thin layer between one spot of the microarray and the surface of one screen-printed electrochemical cell. The accumulation of the enzyme product in the thin film of…
Effect of DNA Aptamer Concentration on the Conductivity of a Water-Gated Al:ZnO Thin-Film Transistor-Based Biosensor
2022
This research was supported by State Education Development Agency, Project No. 1.1.1.2/ 16/I/001, Research Proposal No. 1.1.1.2/VIAA/4/20/590 “Portable diagnostic device based on a biosensor array of 2D material sensing elements”.
Recent advances on aptamer-based biosensors to detection of platelet-derived growth factor.
2018
Platelet-derived growth factor (PDGF-BB), a significant serum cytokine, is an important protein biomarker in diagnosis and recognition of cancer, which straightly rolled in proceeding of various cell transformations, including tumor growth and its development. Fibrosis, atherosclerosis are certain appalling diseases, which PDGF-BB is near to them. Generally, the expression amount of PDGF-BB increases in human life-threatening tumors serving as an indicator for tumor angiogenesis. Thus, identification and quantification of PDGF-BB in biomedical fields are particularly important. Affinity chromatography, immunohistochemical methods and enzyme-linked immunosorbent assay (ELISA), conventional m…
Probing the Conformational States of a pH-Sensitive DNA Origami Zipper via Label-Free Electrochemical Methods
2021
Funding Information: Financial support from EPSRC DTP (grant EP/R513349/1), the Emil Aaltonen Foundation, the Sigrid Jusélius Foundation, the Jane and Aatos Erkko Foundation, and the Vilho, Yrjö and Kalle Väisälä Foundation of the Finnish Academy of Science and Letters is gratefully acknowledged. This work was carried out under the Academy of Finland Centers of Excellence Programme (2014–2019). We acknowledge the provision of facilities and technical support by Aalto University Bioeconomy Facilities and OtaNano—Nanomicroscopy Center (Aalto-NMC) and Micronova Nanofabrication Center. Publisher Copyright: © 2021 The Authors. Published by American Chemical Society DNA origami structures represe…
Straightforward access to water-soluble unsymmetrical sulfoxanthene dyes: application to the preparation of far-red fluorescent dyes with large stoke…
2014
An efficient synthesis of water-soluble unsymmetrical sulforhodamine/sulforhodol fluorophores containing a single julolidine fragment is presented. Owing to their valuable spectral properties in aqueous buffers, these dyes, especially those bearing a free aniline or phenol moiety, are valuable components of fluorogenic probes for a variety of biosensing applications. A further extension of this synthetic methodology to unusual phenols, namely 7-N,N-dialkylamino-4-hydroxy coumarins has enabled us to provide a new family water-soluble dyes of large Stokes’ shift with far-red spectral features.
Modular Breath Analyzer (MBA): Introduction of a Breath Analyzer Platform Based on an Innovative and Unique, Modular eNose Concept for Breath Diagnos…
2021
Exhaled breath analysis for early disease detection may provide a convenient method for painless and non-invasive diagnosis. In this work, a novel, compact and easy-to-use breath analyzer platform with a modular sensing chamber and direct breath sampling unit is presented. The developed analyzer system comprises a compact, low volume, temperature-controlled sensing chamber in three modules that can host any type of resistive gas sensor arrays. Furthermore, in this study three modular breath analyzers are explicitly tested for reproducibility in a real-life breath analysis experiment with several calibration transfer (CT) techniques using transfer samples from the experiment. The experiment …
Metal ion affinity-based biomolecular recognition and conjugation inside synthetic polymer nanopores modified with iron-terpyridine complexes.
2011
Here we demonstrate a novel biosensing platform for the detection of lactoferrin (LFN) via metal-organic frameworks, in which the metal ions have accessible free coordination sites for binding, inside the single conical nanopores fabricated in polymeric membrane. First, monolayer of amine-terminated terpyridine (metal-chelating ligand) is covalently immobilized on the inner walls of the nanopore via carbodiimide coupling chemistry. Second, iron-terpyridine (iron-terPy) complexes are obtained by treating the terpyridine modified-nanopores with ferrous sulfate solution. The immobilized iron-terPy complexes can be used as recognition elements to fabricate biosensing nanodevice. The working pri…