In-column field-amplified sample stacking of biogenic amines on microfabricated electrophoresis devices.

A novel method for performing in-column field-amplified sample stacking (FASS) in chip-based electrophoretic systems is presented. The methodology involves the use of a narrow sample channel (NSC) injector. NSC injectors allow sample plugs to be introduced directly into the separation channel, and subsequent stacking and separation can proceed without any need for leakage control.

Electrophoretic analysis of amines using reversed-phase, reversed-polarity, head-column field-amplified sample stacking and laser-induced fluorescence detection.

This paper describes the use of reversed-phase, reversed-polarity head-column field-amplified sample stacking (HCFASS) for on-line sample concentration in conventional capillary electrophoresis. The effective stacking efficiency was determined as a function of sodium hydroxide concentration in the sample matrix. Results concur with theoretical predictions where stacking efficiency depends on the conductivity (electric field strength) and electrophoretic mobility in the sample matrix solution.

Solution-phase electroluminescence.

We report emissive devices exhibiting electroluminescence in the solution phase. The principle operating mechanism for these devices--direct electronic carrier injection from the electrodes into the carrier bands of the dissolved polymer--resembles that of a conventional solid-state organic light-emitting diode and is distinct from the solvent-mediated electrochemical devices recently reported by Chang et al.

A polydimethylsiloxane/glass capillary electrophoresis microchip for the analysis of biogenic amines using indirect fluorescence detection.

A polydimethylsiloxane-glass capillary microchip is fabricated for the rapid analysis of a mixture of common biogenic amines using indirect fluorescence detection. Using a running buffer of phosphate and 2-propanol, and Rhodamine 110 as a background fluorophore, both co-ionic and counter-ionic systems are explored. Studies demonstrate the separation and analysis of cations using indirect fluorescence detection for the first time in a chip-based system.

Microfluidic routes to the controlled production of nanoparticles.

A microfluidic procedure for the controlled production of cadmium sulfide nanoparticles is described.