Search results for "biosensor"
showing 10 items of 236 documents
Polarimetric Plasmonic Sensing with Bowtie Nanoantenna Arrays
2015
We propose a polarimetric plasmonic biosensor based on bowtie nanoantenna array transducers. Through numerical simulations, based on the finite element method (FEM), we study the phase retardation between the components of light polarized parallel and perpendicular to the major axis of the bowties within the arrays. From a design for high volumetric sensitivity at a wavelength of 780 nm, sensitivities ∼5 rad/RIU is obtained, corresponding to a detection limit of ∼10−7 when using a polarimetric readout platform. Similarly, surface sensitivity of the same array is evaluated by simulating the phase retardation changes induced by the coverage of bioreceptors and analytes of the metallic nanostr…
Hybrid Circuits with Nanofluidic Diodes and Load Capacitors
2017
[EN] The chemical and physical input signals characteristic of micro- and nanofluidic devices operating in ionic solutions should eventually be translated into output electric currents and potentials that are monitored with solid-state components. This crucial step requires the design of hybrid circuits showing robust electrical coupling between ionic solutions and electronic elements. We study experimentally and theoretically the connectivity of the nanofluidic diodes in single-pore and multipore membranes with conventional capacitor systems for the cases of constant, periodic, and white-noise input potentials. The experiments demonstrate the reliable operation of these hybrid circuits ove…
Analysis of multi-spectral photoplethysmograph biosensors
2013
Multi-spectral photoplethysmograph biosensor intended for analysis of peripheral blood volume pulsations at different vascular depths has been experimentally tested. Light emitting diodes with four different wavelengths were used as the light emitters. A single photodiode with multi-channel signal output processing was used as the light detector. This study analyzed rising time difference between wavelengths at systole maximum, wavelengths relations between systole and diastole peak difference. The proposed methodology is discussed.
Model network architectures in vitro on extracellular recording systems using microcontact printing
2001
A PDMS stamp is used to transfer a synthetic peptide in a given pattern to any suitable surface. Using this method two-dimensional neuronal model networks could be formed on glass substrates as well as on electronic devices and adjusted to the given microelectronic structure. The present work focuses on the mechanism of neurite guidance under simplified in vitro conditions, using in vitro guidance cues and outline the incorporation of these interfacial methods into microelectronic sensor devices.
Clinical measurements analysis of multi-spectral photoplethysmograph biosensors
2014
The developed portable multi-spectral photoplethysmograph (MS-PPG) optical biosensor device, intended for analysis of peripheral blood volume pulsations at different vascular depths, has been clinically verified. Multi-spectral monitoring was performed by means of a four – wavelengths (454 nm, 519 nm, 632 nm and 888 nm) light emitted diodes and photodiode with multi-channel signal output processing. Two such sensors can be operated in parallel and imposed on the patient’s skin. The clinical measurements confirmed ability to detect PPG signals at four wavelengths simultaneously and to record temporal differences in the signal shapes (corresponding to different penetration depths) in normal a…
Clinical measurements with multi-spectral photoplethysmography sensors
2012
A portable multi-spectral photoplethysmography device has been used for studies of 40 subjects. Multi-spectral monitoring was performed by means of a four - wavelengths (465 nm, 530 nm, 630 nm and 870 nm) light emitted diodes (LED) and a single photodiode with multi-channel signal output processing. The proposed methodology and potential clinical applications are discussed.
Hybrid molecular materials for optoelectronic devices
2005
Hybrid molecular materials based on semiconductor nanocrystalline metal oxides are a subject of intense research for the development of optoelectronic devices. Such devices follow the strategy of combining high surface area mesoporous materials with optically and electrochemically active molecules. Photovoltaic devices, molecular sensors and biosensors are some of the examples discussed in this paper.
Plasmonic Biosensors for the Detection of Lung Cancer Biomarkers: A Review
2021
Lung cancer is the most common and deadliest cancer type globally. Its early diagnosis can guarantee a five-year survival rate. Unfortunately, application of the available diagnosis methods such as computed tomography, chest radiograph, magnetic resonance imaging (MRI), ultrasound, low-dose CT scan, bone scans, positron emission tomography (PET), and biopsy is hindered due to one or more problems, such as phenotypic properties of tumours that prevent early detection, invasiveness, expensiveness, and time consumption. Detection of lung cancer biomarkers using a biosensor is reported to solve the problems. Among biosensors, optical biosensors attract greater attention due to being ultra-sensi…
Porous Aluminium Oxide Coating for the Development of Spectroscopic Ellipsometry Based Biosensor: Evaluation of Human Serum Albumin Adsorption
2020
An electrochemically synthesised porous anodic aluminium oxide (pAAO) layer has been analysed by means of spectroscopic ellipsometry. The determined thickness of the formed pAAO layer obtained from spectroscopic ellipsometry measurements and modelling was 322.75 ±
A DNA-nanoparticle actuator enabling optical monitoring of nanoscale movements induced by an electric field.
2018
Merging biological and non-biological matter to fabricate nanoscale assemblies with controllable motion and function is of great interest due to its potential application, for example, in diagnostics and biosensing. Here, we have constructed a DNA-based bionanoactuator that interfaces with biological and non-biological matter via an electric field in a reversibly controllable fashion. The read-out of the actuator is based on motion-induced changes in the plasmon resonance of a gold nanoparticle immobilized to a gold surface by single stranded DNA. The motion of the gold nanoparticle and thus the conformational changes of the DNA under varying electric field were analyzed by dark field spect…