New analytical portable instrument for microchip electrophoresis with electrochemical detection

Abstract

A new portable instrument that includes a high voltage power supply, a bipotentiostat, and a chip holder has been especially developed for using microchips electrophoresis with electrochemical detection. The main unit of the instrument has dimensions of 150 x 165 x 70 mm (wxdxh) and consists of a four-outputs high voltage power supply with a maximum voltage of +/-3 KV and an acquisition system with two channels for dual amperometric (DC or pulsed amperometric detection) detection. Electrochemical detection has been selected as signal transduction method because it is relatively easily implemented, since nonoptical elements are required. The system uses a lithium-ion polymer battery and it is controlled from a desktop or laptop PC with a graphical user interface based on LabVIEW connected by serial RS232 or Bluetooth. The last part of the system consists of a reusable chip holder for housing the microchips, which contain all the electrical connections and reservoirs for making the work with microchips easy. The performance of the new instrument has been evaluated and compared with other commercially available apparatus using single- and dual-channel pyrex microchips for the separation of the neurotransmitters dopamine, epinephrine, and 3,4-dihydroxy-L-phenyl-alanine. The reduction of the size of the instrument has not affected the good performance of the separation and detection using microchips electrophoresis with electrochemical detection. Moreover, the new portable instrument paves the way for in situ analysis making the use of microchips electrophoresis easier.

Separation of natural antioxidants using PDMS electrophoresis microchips coupled with amperometric detection and reverse polarity

“…At the same time, electrochemical detection (ED) is an interesting detection mode to be coupled with ME and has been successfully used for the determination of many biologically important compounds . Electrochemical methods are particularly attractive for the determination of antioxidants due to their high sensitivity and specificity for compounds undergoing redox reactions .…”

Recent advances in amino acid analysis by capillary electrophoresis

“…This instrument uses a ±3 kV power supply and an acquisition system with two channels for dual amperometric data for the separation of the neurotransmitters dopamine, epinephrine, and 3,4‐dihydroxy‐ L ‐phenyl‐alanine (DOPA). The separation buffer was optimized (25 mM 2‐(N‐morpholine) ethane sulfonic (MES)‐sodium acetate, pH 5.57) and provided LODs of 2.6, 2.4, and 12.2 μM, respectively 59.…”

Micro Total Analysis Systems for Cell Biology and Biochemical Assays

“…Several recent devices run off batteries, 123,126,127 USB power, 121 or wireless power using RF circuits. 128 These portable options were sufficient to power many important analytical steps, including valving, 123 dielectrophoretic manipulations, 128 electrokinetic separations, 121,126 and electrochemical 126 or LIF detection.…”