Toward million-fold sensitivity enhancement by sweeping in capillary electrophoresis combined with thermal lens microscopic detection using an interface chip.

This paper reports a thermal lens microscope (TLM) detection coupled with capillary electrophoresis (CE) by using an interface chip (IFChip) to achieve highly sensitive detection with high reproducibility. Fused silica capillaries with an inner diameter of 50 microm were directly connected to a microchannel on the IFChip. In comparison with an on-capillary detection method in CE-TLM, ca.

Optimization of an interface chip for coupling capillary electrophoresis with thermal lens microscopic detection.

This paper presents a capillary-to-microchip connection, which can be used as an interface for coupling capillary electrophoresis (CE) with a thermal lens microscope (TLM). It is difficult to directly apply TLM to samples in a capillary with a curved surface, and such an interface chip at the end of a CE separation column is needed for reliable TLM measurements. The dependence of the TLM signal intensity on the TLM detection point in the interface chip and the dependence of the theoretical plate number of CE separation on the channel dimensions of the interface chip were investigated and optimized with a mixture of 4-dimethylaminoazobenze-4'-sulfonyl (DABSYL)-derivatized amino acids (glycine, alanine, methionine, and proline) as a model sample.

Pile-up glass microreactor.

We made a 'pile-up' microreactor in which ten levels of microchannel circuits were integrated to form a single glass entity. Solutions were distributed to each layer via cylindrical holes with a diameter much larger than that of the microchannel. Fabrication of the pile-up reactor was completed using only conventional photolithography, wet etching and thermal bonding techniques, and no special facilities or instruments were required.

Glass microchip with three-dimensional microchannel network for 2 x 2 parallel synthesis.

An integrated multireactor system for 2 x 2 parallel organic synthesis has been developed on a single glass microchip. Three-dimensional channel circuits in the chip were fabricated by laminating three glass plate layers. The fabrication method is a straightforward extension of the conventional one, and topological equivalence for any three-dimensional circuits can be constructed easily with it.

An interface chip connection between capillary electrophoresis and thermal lens microscope.

A thermal lens microscope (TLM) detection of capillary electrophoresis (CE) utilizing microchip technology was developed. Fused-silica capillaries with an inner diameter of 50 microm were directly connected to a microchannel in a microchip. The detection limit by TLM was estimated as 2.

Chemicofunctional membrane for integrated chemical processes on a microchip.

Here we report a design and synthesis of a chemically functional polymer membrane by an interfacial polycondensation reaction and multilayer flow inside a microchannel. Single and parallel dual-membrane structures are successfully prepared by using organic/aqueous two-layer flow and organic/aqueous/organic three-layer flow inside the microchannel followed by an interfacial polycondensation reaction. By using the inner-channel membrane, permeation of ammonia species through the inner-channel membrane is successfully achieved.

Three-layer flow membrane system on a microchip for investigation of molecular transport.

A stable three-layer flow system, water/organic solvent/water, has been successfully applied for the first time in a microchannel to get rapid transport through an organic liquid membrane. In the continuous laminar flow region, the analyte (methyl red) was rapidly extracted across the microchannel from the donor to the acceptor phase through the organic solvent phase (cyclohexane). Thermal lens microscopy was used to monitor the process.

Stabilization of liquid interface and control of two-phase confluence and separation in glass microchips by utilizing octadecylsilane modification of microchannels.

We demonstrated a liquid/liquid and a gas/liquid two-phase crossing flow in glass microchips. A 250-microm-wide microchannel for aqueous-phase flow was fabricated on a top glass plate. Then, as a way to utilize the surface energy difference for stable phase confluence and separation, a 250-microm-wide microchannel for organic-phase (or gas-phase) flow was fabricated on a bottom glass plate and the wall was chemically modified by octadecylsilane (ODS) group.

Continuous-flow chemical processing on a microchip by combining microunit operations and a multiphase flow network.

A new design and construction methodology for integration of complicated chemical processing on a microchip was proposed. This methodology, continuous-flow chemical processing (CFCP), is based on a combination of microunit operations (MUOs) and a multiphase flow network. Chemical operations in microchannels, such as mixing, reaction, and extraction, were classified into several MUOs.