Picoliter enzyme reactor on a nanofluidic device exceeding the bulk reaction rate

Abstract

<p>Single-cell analyses have recently become important to understand cell heterogeneity, the mechanism of cell function, and diseases. In contrast to single-cell analyses that target nucleic acids, single-cell protein analyses still...</p>

Metal-Free Fabrication of Fused Silica Extended Nanofluidic Channel to Remove Artifacts in Chemical Analysis

“…For comparison, the TMB reaction rate was measured using a 20 μM K 2 CrO 7 solution, for which the rate was 0.33 μM/min. We have previously reported that the reaction rate in nanochannels can be increased by 10 1 times due to size confinement effects [ 27 ]. Therefore, whether or not to consider the size confinement effects would require at least a micromolar order (apparent concentration by nanochannel surface-to-volume ratio) reaction of Cr 6+ , which would have a significant effect on the chemical process.…”

“…For example, the biotin–streptavidin reaction [ 21 , 22 ], hybridization of microRNA [ 23 ], enzymatic reactions [ 24 ], and electrochemical reactions [ 25 , 26 ] have been performed at solid/liquid interfaces in nanochannels. In our group, a picoliter enzymatic reactor [ 27 ] using an enzyme-immobilized nanochannel, and femtoliter chromatography devices [ 28 , 29 ] using silica surfaces or C 18 -modified surfaces have been developed, and their superior performance over conventional bulk methods has been verified. A femtoliter enzyme-linked immunosorbent assay (ELISA) [ 30 ] using antibody-immobilized nanochannels enabled protein quantification at the single–molecule level.…”

A simple and reversible glass–glass bonding method to construct a microfluidic device and its application for cell recovery

“…Even though these values of bonding strength could not tell exact leaking pressure, 600 kPa were high enough to cover practical uses of microfluidic devices. [52][53][54][55] In addition, 6 h of clip-pressing had advantages in low risk of damaging glasses by thermal expansion/ contraction and total length of bonding period. Meanwhile, fusion bonding was overnight process, typically requiring more than 8 h for glass heating, bonding, and cooling in a furnace with risk of thermally damaging glasses.…”

Stable Formation of Aqueous/Organic Parallel Two-phase Flow in Nanochannels with Partial Surface Modification

“…[22][23][24][25][26][27] Our group has been exploiting this field utilizing 10-1000 nm sized nanochannels on a glass substrate. 28 Based on the high surface area effect in such a small volume, novel unit operations at the molecular level such as single-molecule ELISA (enzyme-linked immunosorbent assay), 29 single DNA molecule sorting, 30 nano-chromatography using the channel as a separation column, 31 and picoliter enzyme reactors 32 have been performed. These operations are called nano unit operations (NUOs) and in order to interconnect NUOs and realize integrated nanofluidic analytical systems, formation of parallel multiphase flows in nanochannels is required.…”