In recent decades,the properties and behaviors of nanofluidic devices have been widely explored in varied subjects such as engineering,physics,chemistry,and biology.Among the rich properties of nanofluidics,ionic curr...In recent decades,the properties and behaviors of nanofluidic devices have been widely explored in varied subjects such as engineering,physics,chemistry,and biology.Among the rich properties of nanofluidics,ionic current rectification(ICR) is a unique phenomenon arising from asymmetric nanofluidic devices with electric double layer(EDL) overlapped.The ICR property is especially useful in applications including energy conversion,mass separation,sea water purification and bioanalysis.In this review,the ICR property in nanofluidics as well as the underlying mechanism is demonstrated.The influencing factors concerning to the ICR property are systematically summarized.The asymmetric geometry as well as the charge distribution is in charge of the ICR behavior occurring in nanofluidic devices.This review is aimed at readers who are interested in the fundamentals of mass transport in nanofluidics in general,as well as those who are willing to apply nanofluidics in various research fields.展开更多
A systematic understanding of the mechanism in the rectification and capacitance of nanochannels and their regulation with the electrolyte concentration and electrical bias is pivotal for its wide applications to nano...A systematic understanding of the mechanism in the rectification and capacitance of nanochannels and their regulation with the electrolyte concentration and electrical bias is pivotal for its wide applications to nanofluidic electronics,ion separation,energy storage,and molecule sensing.Single unipolar and bipolar cylindrical nanochannels through polymer film were fabricated using single ion bombardment and track etching.Cyclic voltammetry results show that the bipolar nanochannel switches from rectification to capacitance as the electrolyte concentration decreases.Electrochemical impedance spectroscopy revealed that the capacitive impedance fraction in the bipolar nanochannel is regulated by electrolyte concentration and voltage.The switch from rectification to capacitance in the polymer nanochannel is well explained through a fluidic p-n junction model with a variable ion depletion layer regulated by the applied bias voltage,which is supported by the multi-physics simulation using Poisson-Nernst-Planck and Navier-Stokes solution.This work provides a mechanistic insight into the ionic current rectification and ionic capacitance in complex ionic nanochannels and paves the way for biomimetic nanofluidic electronics design.展开更多
Nanofluidics is a recent appearing research field, introduced in 1995 as an analogue of the field of microfluidics, and has been becoming popular in the past few years. The proximity of the channel dimension, the Deby...Nanofluidics is a recent appearing research field, introduced in 1995 as an analogue of the field of microfluidics, and has been becoming popular in the past few years. The proximity of the channel dimension, the Debye length, and the size of biomolecules such as DNA and proteins gives the unique features of nanofluidic devices. Of various unique properties of the nanofluidics, mass transport in nanochannel plays determining roles in fundamental reaches and practical applications of nanofluidic device. Thus, much work including numerical and experimental researches has been performed to investigate the mass transport behaviors in nanofluidic devices. This review summarizes the fabrication technologies for nanofluidic devices, the mass transport behaviors in nanochannel, and their applications in bioanalysis. The main focus will be laid on the effects of nanochannel size and surface charge on mass transport including electrokinetic transport of charged analytes, diffusion of electric neutral molecules, ionic current rectification, concentration polarization, nonlinear electrokinetic flow at the micro-nanofluidic interfaces.展开更多
基金supported by the National Natural Science Foundation of China(Nos.21874155,21575163)the Natural Science Foundation of Jiangsu Province(No.BK20191316)+2 种基金the Double First-Class University Project(No.CPU2018GY25)the State Key Laboratory of Analytical Chemistry for Life Science(No.SKLACLS1919)the Qing-Lan Project ofjiangsu Province(2019)。
文摘In recent decades,the properties and behaviors of nanofluidic devices have been widely explored in varied subjects such as engineering,physics,chemistry,and biology.Among the rich properties of nanofluidics,ionic current rectification(ICR) is a unique phenomenon arising from asymmetric nanofluidic devices with electric double layer(EDL) overlapped.The ICR property is especially useful in applications including energy conversion,mass separation,sea water purification and bioanalysis.In this review,the ICR property in nanofluidics as well as the underlying mechanism is demonstrated.The influencing factors concerning to the ICR property are systematically summarized.The asymmetric geometry as well as the charge distribution is in charge of the ICR behavior occurring in nanofluidic devices.This review is aimed at readers who are interested in the fundamentals of mass transport in nanofluidics in general,as well as those who are willing to apply nanofluidics in various research fields.
基金supported by the National Key R&D Program of China(Grant No.2021YFA1601400)the National Natural Science Foundation of China(Grant Nos.12241201,1197283,12375287,and U1632271).
文摘A systematic understanding of the mechanism in the rectification and capacitance of nanochannels and their regulation with the electrolyte concentration and electrical bias is pivotal for its wide applications to nanofluidic electronics,ion separation,energy storage,and molecule sensing.Single unipolar and bipolar cylindrical nanochannels through polymer film were fabricated using single ion bombardment and track etching.Cyclic voltammetry results show that the bipolar nanochannel switches from rectification to capacitance as the electrolyte concentration decreases.Electrochemical impedance spectroscopy revealed that the capacitive impedance fraction in the bipolar nanochannel is regulated by electrolyte concentration and voltage.The switch from rectification to capacitance in the polymer nanochannel is well explained through a fluidic p-n junction model with a variable ion depletion layer regulated by the applied bias voltage,which is supported by the multi-physics simulation using Poisson-Nernst-Planck and Navier-Stokes solution.This work provides a mechanistic insight into the ionic current rectification and ionic capacitance in complex ionic nanochannels and paves the way for biomimetic nanofluidic electronics design.
基金supported by the National Basic Research Program (2012CB933804)the National Natural Science Foundation of China (20890020, 20975047, 21035002)+2 种基金the National Science Fund for Creative Research Groups (21121091)Specialized Research Fund for the Doctoral Program of Higher Fducation (200802840012)the Natural Science Foundation of Jiangsu Province (BK2010009)
文摘Nanofluidics is a recent appearing research field, introduced in 1995 as an analogue of the field of microfluidics, and has been becoming popular in the past few years. The proximity of the channel dimension, the Debye length, and the size of biomolecules such as DNA and proteins gives the unique features of nanofluidic devices. Of various unique properties of the nanofluidics, mass transport in nanochannel plays determining roles in fundamental reaches and practical applications of nanofluidic device. Thus, much work including numerical and experimental researches has been performed to investigate the mass transport behaviors in nanofluidic devices. This review summarizes the fabrication technologies for nanofluidic devices, the mass transport behaviors in nanochannel, and their applications in bioanalysis. The main focus will be laid on the effects of nanochannel size and surface charge on mass transport including electrokinetic transport of charged analytes, diffusion of electric neutral molecules, ionic current rectification, concentration polarization, nonlinear electrokinetic flow at the micro-nanofluidic interfaces.
