Fluidic and Electronic Transport in Silicon Nanotube Biosensors

MRS Advances ◽  
2016 ◽  
Vol 1 (56) ◽  
pp. 3761-3766 ◽  
Author(s):  
Nicolas Hibst ◽  
Annina M. Steinbach ◽  
Steffen Strehle
Keyword(s):  
Electronic Transport ◽  
Field Effect Transistors ◽  
Building Blocks ◽  
Microfluidic System ◽  
Label Free ◽  
Ion Diffusion ◽  
Charge Sensing ◽  
Silicon Nanotubes ◽  
Order Of Magnitude ◽  
Electronic Sensing

ABSTRACTSilicon nanotubes (SiNTs) represent unique building blocks for future nanoscale biosensor devices merging electronic sensing and nanofluidics. Configured as ion-sensitive field effect transistors (ISFETs), SiNTs have great potential for charge sensing or label-free chemical detection in minute sample volumes flowing through their inner cavity. In the present study, doped SiNTs were synthesized from the gas phase in a bottom-up approach. To study their nanofluidic and electronic transport properties, single SiNTs were functionally integrated as ISFETs and coupled to a microfluidic system. The experimental results for ion diffusion through a SiNT are in full agreement with numerical calculations based on Fick's second law if a diffusion coefficient is assumed approximately one order of magnitude smaller than the bulk value.

The Coarse Scale Velocity

2017 ◽  
Author(s):  
Philip Isett
Keyword(s):  
Velocity Field ◽  
Building Blocks ◽  
Coarse Scale ◽  
Divergence Equation ◽  
Higher Derivatives ◽  
Order Of Magnitude ◽  
Derivatives Of

This chapter deals with the coarse scale velocity. It begins the proof of Lemma (10.1) by choosing a double mollification for the velocity field. Here ∈ᵥ is taken to be as large as possible so that higher derivatives of velement are less costly, and each vsubscript Element has frequency smaller than λ‎ so elementv⁻¹ must be smaller than λ‎ in order of magnitude. Each derivative of vsubscript Element up to order L costs a factor of Ξ‎. The chapter proceeds by describing the basic building blocks of the construction, the choice of elementv and the parametrix expansion for the divergence equation.

Influence of VC and FEC Additives on Interphase Properties of Carbon in Li-Ion Cells Investigated by Combined EIS & EQCM-D

2020 ◽  
Author(s):  
Paul Kitz ◽  
Matthew Lacey ◽  
Petr Novák ◽  
Erik Berg
Keyword(s):  
Electrochemical Impedance ◽  
Solid Electrolyte Interphase ◽  
Electrochemical Quartz Crystal Microbalance ◽  
Gas Analysis ◽  
Side Reactions ◽  
Ion Diffusion ◽  
Battery Cell ◽  
Anode Passivation ◽  
Order Of Magnitude ◽  
Li Ion

<div>The electrolyte additives vinylene carbonate (VC) and fluoroethylene carbonate (FEC) are well known for increasing the lifetime of a Li-ion battery cell by supporting the formation of an effective solid electrolyte interphase (SEI) at the anode. In this study combined simultaneous electrochemical impedance spectroscopy (EIS) and <i>operando</i> electrochemical quartz crystal microbalance with dissipation monitoring (EQCM-D) are employed together with <i>in situ</i> gas analysis (OEMS) to study the influence of VC and FEC on the passivation process and the interphase properties at carbon-based anodes. In small quantities both additives reduce the initial interphase mass loading by 30 to 50 %, but only VC also effectively prevents continuous side reactions and improves anode passivation significantly. VC and FEC are both reduced at potentials above 1 V vs. Li<sup>+</sup>/Li in the first cycle and change the SEI composition which causes an increase of the SEI shear storage modulus by over one order of magnitude in both cases. As a consequence, the ion diffusion coefficient and conductivity in the interphase is also significantly affected. While small quantities of VC in the initial electrolyte increase the SEI conductivity, FEC decomposition products hinder charge transport through the SEI and thus increase overall anode impedance significantly. </div>

scholarly journals Microfluidics for the rapid and controlled preparation of organic nanotubes of bent-core based dendrimers

2021 ◽  
Author(s):  
M. Blanca Ros ◽  
Martín Castillo-Vallés ◽  
Pilar Romero ◽  
Victor Sebastian
Keyword(s):  
Building Blocks ◽  
Microfluidic System ◽  
Promising Tool ◽  
Organic Nanotubes ◽  
Controlled Preparation

Recently, bent-core molecules have arised as excellent building blocks for the obtaining of nanostructures in solvents. Herein, we report the use of a coaxial microfluidic system as a promising tool...

scholarly journals Affinity Sensors for the Diagnosis of COVID-19

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 390
Author(s):  
Maryia Drobysh ◽  
Almira Ramanaviciene ◽  
Roman Viter ◽  
Arunas Ramanavicius
Keyword(s):  
Field Effect Transistors ◽  
Resonance Field ◽  
Analytical Signal ◽  
Nucleic Acid Hybridization ◽  
Detection Methods ◽  
Label Free ◽  
Infected People ◽  
Label Free Detection ◽  
Main Instrument ◽  
Antigen Antibody

The coronavirus disease 2019 (COVID-19) outbreak caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was proclaimed a global pandemic in March 2020. Reducing the dissemination rate, in particular by tracking the infected people and their contacts, is the main instrument against infection spreading. Therefore, the creation and implementation of fast, reliable and responsive methods suitable for the diagnosis of COVID-19 are required. These needs can be fulfilled using affinity sensors, which differ in applied detection methods and markers that are generating analytical signals. Recently, nucleic acid hybridization, antigen-antibody interaction, and change of reactive oxygen species (ROS) level are mostly used for the generation of analytical signals, which can be accurately measured by electrochemical, optical, surface plasmon resonance, field-effect transistors, and some other methods and transducers. Electrochemical biosensors are the most consistent with the general trend towards, acceleration, and simplification of the bioanalytical process. These biosensors mostly are based on the determination of antigen-antibody interaction and are robust, sensitive, accurate, and sometimes enable label-free detection of an analyte. Along with the specification of biosensors, we also provide a brief overview of generally used testing techniques, and the description of the structure, life cycle and immune host response to SARS-CoV-2, and some deeper details of analytical signal detection principles.

scholarly journals Biologically sensitive field-effect transistors: from ISFETs to NanoFETs

2016 ◽  
Vol 60 (1) ◽  
pp. 81-90 ◽  
Author(s):  
Vivek Pachauri ◽  
Sven Ingebrandt
Keyword(s):  
Field Effect ◽  
Gate Dielectric ◽  
Gate Dielectrics ◽  
Field Effect Transistors ◽  
Silicon Nanowire ◽  
Label Free ◽  
Biomolecular Detection ◽  
New Device ◽  
Label Free Detection ◽  
History Of

Biologically sensitive field-effect transistors (BioFETs) are one of the most abundant classes of electronic sensors for biomolecular detection. Most of the time these sensors are realized as classical ion-sensitive field-effect transistors (ISFETs) having non-metallized gate dielectrics facing an electrolyte solution. In ISFETs, a semiconductor material is used as the active transducer element covered by a gate dielectric layer which is electronically sensitive to the (bio-)chemical changes that occur on its surface. This review will provide a brief overview of the history of ISFET biosensors with general operation concepts and sensing mechanisms. We also discuss silicon nanowire-based ISFETs (SiNW FETs) as the modern nanoscale version of classical ISFETs, as well as strategies to functionalize them with biologically sensitive layers. We include in our discussion other ISFET types based on nanomaterials such as carbon nanotubes, metal oxides and so on. The latest examples of highly sensitive label-free detection of deoxyribonucleic acid (DNA) molecules using SiNW FETs and single-cell recordings for drug screening and other applications of ISFETs will be highlighted. Finally, we suggest new device platforms and newly developed, miniaturized read-out tools with multichannel potentiometric and impedimetric measurement capabilities for future biomedical applications.

Boronate ester post-functionalization of PPEs: versatile building blocks for poly(2,2′-(1-(4-(1,2-di(thiophen-2-yl)vinyl)phenyl)-2-(2,5-dioctylphenyl)ethene-1,2-diyl)dithiophene) and application in field effect transistors

2015 ◽  
Vol 3 (39) ◽  
pp. 10074-10078 ◽  
Author(s):  
Junwei Yang ◽  
Moyun Chen ◽  
Ji Ma ◽  
Wei Huang ◽  
Haoyun Zhu ◽  
...  
Keyword(s):  
Field Effect ◽  
Field Effect Transistors ◽  
Building Blocks ◽  
Boronate Esters ◽  
Boronate Ester ◽  
Post Functionalization

Novel boronate esters synthesized by the post-functionalization of PPEs and oligomers can provide an versatile platform for analogues.

Transport properties of hydrogen passivated silicon nanotubes and silicon nanotube field effect transistors

2017 ◽  
Vol 5 (6) ◽  
pp. 1409-1413 ◽  
Author(s):  
E. Montes ◽  
U. Schwingenschlögl
Keyword(s):  
Transport Properties ◽  
Field Effect ◽  
Field Effect Transistors ◽  
Silicon Nanotubes ◽  
High Transconductance ◽  
Passivated Silicon ◽  
Silicon Nanotube

Hydrogen passivated silicon nanotube field effect transistors are predicted to combine high transconductance with low sub-threshold swing.

scholarly journals Development of a label-free microfluidic impedimetric immunoassay for anti-SPAG16 antibody

2021 ◽  
Author(s):  
T Froyen ◽  
F Vreys ◽  
L Slaets ◽  
V Somers ◽  
R Thoelen
Keyword(s):  
Multiple Sclerosis ◽  
Flow Cell ◽  
Microfluidic System ◽  
Electrochemical Analysis ◽  
Antigen Binding ◽  
Label Free ◽  
Linear Pattern ◽  
Novel Approach ◽  
Zijn Voor ◽  
Pet Foils

ABSTRACTA recently found biomarker regarding multiple sclerosis, namely the anti-SPAG16 antibody (Ab), could be a potential way for early detection, prognosis and diagnosis of said autoimmune disease. Merging electrochemical analysis with a microfluidic system is a novel approach, which avoids the use of labelling steps as seen in traditional ELISA immunoassays. In this study, aluminium interdigitated electrodes on polystyrene-coated PET foils were implemented in a microfluidic flow cell to bind and detect SPAG16 Abs by impedimetric measurements. The coated PET foils showed a clear affinity for the fusion protein SPAG16-THIO and thioredoxin (THIO). Determining sensitivity and specificity of antibody-antigen binding using a microfluidic ELISA immunoassay has revealed the test to be unreliable by showing no linear pattern of a dilution series of the standard and producing skewed inconsistent results. The impedimetric analysis showed opposite results of what one would expect. The systems efficiency is in need to be revised and optimised before undergoing actual diagnostic tests. Further advancement could be done by reducing leakage, securing a more stable entrance for injection and circumventing the occurence of air bubbles in the wells.SAMENVATTINGMultiple sclerosis (MS) is een auto-immune ziekte, gekenmerkt door inflammatie van het centraal zenuwstelsel en demyelinisatie van axonen. Een recent gevonden proteïne, namelijk het anti-SPAG16 antilichaam, is bewezen een biomerker te zijn voor MS. Met behulp van een elektrochemisch analytisch systeem gecombineerd met microfluidica zou men anti-SPAG16 antilichamen kunnen opsporen voor vroegtijdige detectie, prognose en diagnose. Het grote voordeel tegenover traditionele ELISA testen is het elimineren van labelling stappen waardoor de immunoassay goedkoper en gebruiksvriendelijk wordt. In deze studie werden overlappende aluminium elektrodes op polystyreen-gecoate PET-plaatjes geïmplementeerd in een microfluidische flow cell voor binding en detectie van anti-SPAG16 antilichamen door middel van impedimetrische metingen. De gecoate PET-plaatjes vertonen een duidelijke affiniteit voor 0,1 μg/ml SPAG16 en THIO. Het bepalen van sensitiviteit en specificiteit van antilichaam-antigen binding, gebruikmakende van een ELISA immunoassays, gaf aan dat de test onbetrouwbaar is doordat geen duidelijk patroon voor standaardoplossingen zichtbaar was en resultaten vertekend en inconsistent bleken te zijn. De impedimetrische analyse vertoonde tevens onbetrouwbare resultaten, waarbij een omgekeerd effect werd geobserveerd van wat er in theorie zou moeten gebeuren. De efficiëntie van het systeem moet herzien en geoptimaliseerd worden voordat men het voor diagnostische testen kan gebruiken. Verdere vorderingen zouden gerealiseerd kunnen worden door lekkages te reduceren, steviger bevestigen van de PDMS-ingang en de ontwikkeling van luchtbellen in de wells te vermijden.

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