Poly(methylmethacrylate) and Topas capillary electrophoresis microchip performance with electrochemical detection

Abstract

A capillary electrophoresis (CE) microchip made of a new and promising polymeric material: Topas (thermoplastic olefin polymer of amorphous structure), a cyclic olefin copolymer with high chemical resistance, has been tested for the first time with analytical purposes, employing an electrochemical detection. A simple end-channel platinum amperometric detector has been designed, checked, and optimized in a poly-(methylmethacrylate) (PMMA) CE microchip. The end-channel design is based on a platinum wire manually aligned at the exit of the separation channel. This is a simple and durable detection in which the working electrode is not pretreated. H(2)O(2) was employed as model analyte to study the performance of the PMMA microchip and the detector. Factors influencing migration and detection processes were examined and optimized. Separation of H(2)O(2) and L-ascorbic acid (AsA) was developed in order to evaluate the efficiency of microchips using different buffer systems. This detection has been checked for the first time with a microchip made of Topas, obtaining a good linear relationship for mixtures of H(2)O(2) and AsA in different buffers.

Fast and versatile fabrication of PMMA microchip electrophoretic devices by laser engraving

“…On the other extreme, techniques using paper and polyester-toner have been used to manufacture chips in less than 10 min with a cost lower than $ 0.10 per device, but the chemistry and topography of the materials often hinder the applicability of the technology [10,14,15]. Besides these examples, a range of polymers have emerged as alternative materials to fabricate ME devices [16][17][18][19]. In most cases, these plastics offer an adequate balance between fabrication procedures, cost, and analytical performance.…”

Electroactive intercalators for DNA analysis on microchip electrophoresis

“…The 250 mm diameter gold wire working electrode was manually aligned at the outlet of the separation channel as previously reported [10]. In brief, the wire was introduced in the reservoir with the aid of a micropipette tip, then, it was adhered to the microchip with Araldit.…”

“…Several polymers such as poly(methylmethacrylate) (PMMA) [4], PDMS [5], polycarbonate (PC) [6], polyester [7], and poly(ethylenterephthalate) (PET) [8] have been employed. Recently, cyclic olefin polymers and copolymers such as Zeonor [9] or thermoplastic olefin polymer of amorphous structure (Topas) [10] have also received attention due to their high chemical resistance, good machinability, and optical transparency.…”

“…The working electrode can be permanently integrated on-chip by means of thin-films made of platinum [23,24], gold [25][26][27], copper [26], or carbon [28] placed close to the channel exit. Other approach is based on an off-chip alignment of replaceable disk [10,[29][30][31][32][33] or thick-film [33][34][35] working electrodes. In this case, the working electrode could be replaced when surface fouling happened.…”

Permanent surface modification of polymeric capillary electrophoresis microchips for protein and peptide analysis

“…The most commonly used polymers include PDMS [13][14][15], poly(methyl methacrylate) (PMMA) [16][17][18], polystyrene (PS) [19,20], polycarbonate (PC) [21,22], polyethylene terephthalate (PET/PETG) [23,24], polyimide (PI) [25,26], and polycycloolefin (PCOC, under the commercial name of Topas or Zeonex/Zeonor) [27][28][29]. Meanwhile, many mature polymer machining techniques such as injection molding [30], hot embossing [31], casting [32], and laser ablation [33] have been tested for the fabrication of polymeric microfluidic devices.…”