Confined Nanopipette-A new microfluidic approach for single cell analysis

Nested-channel for on-demand alternation between electrospray ionization regimes

“…20 External pump-driven ESI could reduce ow rates for micrometer-sized emitter tip down to 0.3 nL min À1 . 9,21 Although a wealth of methods have been developed in the electrochemical eld to manufacture nanopipette, 22 the efforts of lowering the ESI ow rate by using smaller emitter tips have been constrained by practical obstacles such as emitter clogging, 23 nanometer tip fabrication, 24 and sample handling. 13 Besides using the circular opening of the capillary tips to form ESI meniscus that covers the whole tip opening, other emitter congurations have been found to be effective as well to forming the ESI meniscus.…”

Selective Sensing of Proteins Using Aptamer Functionalized Nanopore Extended Field‐Effect Transistors

“…[6,7] Single molecules techniques, such as nanopore sensors are becoming popular due to their label-free operation, ease of fabrication, the ability of active transportation, and in some cases, the ability to tailor the sensor chemistry via surface modification. [8][9][10][11][12][13][14] Nanopores have been widely used for the detections of nucleic acids, DNA sequencing, [15] and protein sensing. [16][17][18][19][20][21][22][23] However, detection of proteins remains challenging due to fast analyte transport, low capture rates, and the need for relatively high protein concentration.…”

Direct Fabrication of Freestanding and Patterned Nanoporous Junctions in a 3D Micro‐Nanofluidic Device for Ion‐Selective Transport

“…[ 1–3 ] In a nanoscale channel, the dimension of the channel becomes comparable to an electrical double layer (EDL), and thus, the EDL is eventually overlapped, which allows for ion‐selective transport: repelling co‐ions (to the surface charge of the nanoscale channel) and transporting counterions. [ 4–7 ] Therefore, electrokinetic properties in the nanoscale channels exhibit different behaviors compared with the microscale and macroscale channels, such as ion concentration polarization (ICP) [ 8 ] and ion rectification. [ 9–11 ] These unique electrokinetic properties enabled the nanofluidics‐based devices to be implemented in various research fields such as preconcentration, [ 12 ] water desalination, [ 13,14 ] energy harvesting, [ 15 ] nanofluidic transistors, [ 16 ] chemical mixing, [ 17,18 ] and separation.…”