Measurement and control of the ion diffusion coefficient in a nanochannel

Tsai, Yu-Tze; Chang, Kang J.; Wang, Gou‐Jen

doi:10.1007/s00542-013-1751-x

Cited by 4 publications

(2 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The high sensitivity can be attributed to higher active surface area on the nanoporous membrane which enabled the site-specific immobilization and control of DNA orientation and crowdedness 38 and higher pore resistance as an impact of electrical double layer on electrolyte concentration. 6 The latter causes the smaller pores to encounter strictly and tightly flowing electrical double layer on each side of the pore wall which initiates ion movement blockings inside the pore, high resistance in the system leading to signal amplification, 39,40 and low translocation velocity due to intense interaction between DNA and nanoporous surface. 19,20,41 Following up the optimum analytical performance of Au nanoporous EGFET made by 100 nm PS template and 40 nm thick Au film, this substrate was subsequently used for specificity test.…”

Section: Resultsmentioning

confidence: 99%

A Colloidal Nanopatterning and Downscaling of a Highly Periodic Au Nanoporous EGFET Biosensor

Purwidyantri

Kamajaya

Chen

et al. 2018

J. Electrochem. Soc.

View full text Add to dashboard Cite

The nanopattern of highly ordered and uniform Au nanoporous membranes with different sizes and thicknesses and the downscaling approach through the combination of colloidal based nanosphere lithography (NSL) and thermal evaporation was proposed to fabricate an extending-gate field effect transistor (EGFET) membrane. The fabrication involved the use of PS nanospheres templates of 500 nm and 100 nm in diameters and various Au thickness of 10, 25 and 40 nm. Carried out in the detection of Staphylococcus aureus 16S rRNA hybridization test with analytical range of 10 1 -10 6 pM DNA targets, the smaller the Au nanoporous diameter made up by the thicker Au layer produced a gradual improvement in potentiometric study. The Au-nanoporous produced by the thickest Au film at 40 nm and smaller diameter of PS nanospheres (100 nm) demonstrated the most optimum threshold voltage shift and limit of detection (LOD) of ∼1 pM altogether with remarkable specificity in the presence of highly concentrated non-specific DNA of other pathogens. Analytical outcomes point out that smaller, periodic and uniform nanoporous EGFET membrane facilitated the larger hybridization signal due to the higher active surface area enabling the more optimum control of DNA orientation and immobilization. The replacement of Ion Selective Field Effect Transistor (ISFET) with extending gate FET (EGFET) structure has brought electrochemical DNA sensor to a new era of semiconductor genetics. EGFET enables the isolation of the sensing membrane apart from the MOS-FET part and offers numbers of advantages including cost-effective fabrication, simple structure, packaging simplicity, long term stability, resistance to light and temperature and also disposable gate. 1,2In constructing an extending gate, beside a variety of metallic thin films, nanoporous materials act as a potential candidate for sensing membrane materials owing to its higher surface area to volume ratio than the planar surface due to its three-dimensional topography which inherently results in signal amplification.3,4 Small pore diameter establishment has greatly targeted and aroused attention in sensor fabrication due to its excellent capabilities in providing greater sensitivity and performance related to the reinforcement of ion transport and molecules translocation. 5,6 Numbers of studies focused on porous FET with a range of size from meso to macropores (nm scales) and with different materials. Semiconductive organic network, e.g Ni 3 (HITP) 2 , 7 nanoporous silicon 8-10 and porous platinum 11 have also been proven effective in numbers of chemical sensors since they provide a wide range of application on voltage-gated ion channels or microfluidic chips beneficial for sensitivity improvement in ion or gas sensor. Nevertheless, these nanoporous structures are somehow generated in a z E-mail: cslai@mail.cgu.edu.tw randomly disoriented structure while the downscaling of the pore size with simple and cost-effective techniques and instrumentation remains challenging. The emergence of a highly oriente...

show abstract

Section: Resultsmentioning

confidence: 99%

A Colloidal Nanopatterning and Downscaling of a Highly Periodic Au Nanoporous EGFET Biosensor

Purwidyantri

Kamajaya

Chen

et al. 2018

J. Electrochem. Soc.

View full text Add to dashboard Cite

show abstract

“…With the rapid development of nanofabrication technology, the demand for nanofluidic devices with the one-dimensional size smaller than 100 nm is continuously increasing [11]. Nanofluidic chips can also be effectively used for virus detection [12], nanoparticle manipulation [13], and the study of ion diffusion [14]. However, the detection efficiency and sensitivity of the nanofluidic chips depend on the feature dimensions and distribution of the nanochannels.…”

Section: Introductionmentioning

confidence: 99%

Fabrication of polydimethylsiloxane nanofluidic chips under AFM tip-based nanomilling process

et al. 2019

View full text Add to dashboard Cite

In current research realm, polydimethylsiloxane (PDMS)-based nanofluidic devices are widely used in medical, chemical, and biological applications. In the present paper, a novel nanomilling technique (consisting of an AFM system and a piezoelectric actuator) was proposed to fabricate nanochannels (with controllable sizes) on PDMS chips, and nanochannel size was controlled by the driving voltage and frequency inputted to the piezoelectric actuator. Moreover, microchannel and nanochannel molds were respectively fabricated by UV lithography and AFM tip-based nanomilling, and finally, PDMS slabs with micro/nanochannels were obtained by transfer process. The influences of PDMS weight ratio on nanochannel size were also investigated. The bonding process of microchannel and nanochannel slabs was conducted on a homemade alignment system consisted of an optical monocular microscope and precision stages. Furthermore, the effects of nanochannel size on electrical characteristics of KCl solution (concentration of 1 mM) were analyzed. Therefore, it can be concluded that PDMS nanofluidic devices with multiple nanochannels of sub-100-nm depth can be efficiently and economically fabricated by the proposed method. Electronic supplementary material The online version of this article (10.1186/s11671-019-2962-6) contains supplementary material, which is available to authorized users.

show abstract

Ion diffusion coefficient measurements in nanochannels at various concentrations

Wang

Zhang²,

Xue

et al. 2014

Biomicrofluidics

View full text Add to dashboard Cite

Diffusion is one of the most fundamental properties of ionic transport in solutions. Here, we present experimental studies and theoretical analysis on the ion diffusion in nanochannels. Based on Fick's second law, we develop a current monitoring method to measure ion diffusion coefficient of high solution concentrations in nanochannels. This method is further extended to the cases at medium and low concentrations. Through monitoring ionic current during diffusion, we obtain diffusion coefficients of potassium chloride solution at different concentrations in nanochannels. These diffusion coefficients within the confined space are close to theirs bulk values. It is also found that the apparent ion diffusion equilibrium in the present experiments is very slow at low concentration, which we attribute to the slow equilibrium of the nanochannel surface charge. Finally, we get a primary acknowledge of the equilibrium rate between the nanochannel surface charge and electrolyte solution. The results in this work have improved the understanding of nanoscale diffusion and nanochannel surface charge and may be useful in nanofluidic applications such as ion-selective transport, energy conversion, and nanopore biosensors.

show abstract

Measurement and control of the ion diffusion coefficient in a nanochannel

Cited by 4 publications

References 34 publications

A Colloidal Nanopatterning and Downscaling of a Highly Periodic Au Nanoporous EGFET Biosensor

A Colloidal Nanopatterning and Downscaling of a Highly Periodic Au Nanoporous EGFET Biosensor

Fabrication of polydimethylsiloxane nanofluidic chips under AFM tip-based nanomilling process

Ion diffusion coefficient measurements in nanochannels at various concentrations

Contact Info

Product

Resources

About