Carbon Nanotube/Poly(methyl methacrylate) (CNT/PMMA) Composite Electrode Fabricated by In Situ Polymerization for Microchip Capillary Electrophoresis

Abstract

We describe the development and application of a novel carbon nanotube/poly(methyl methacrylate) (CNT/PMMA) composite electrode as a sensitive amperometric detector of microchip capillary electrophoresis (CE). The composite electrode was fabricated by the in situ polymerization of a mixture of CNTs and prepolymerized methyl methacrylate in the microchannel of a piece of fused silica capillary under heat. The performance of this unique system was demonstrated by the separation and detection of phenolic pollutants and purines. The new CNT-based CE detector offered significantly lower operating potentials, yielded substantially enhanced signal-to-noise characteristics, and exhibited resistance to surface fouling and, hence, enhanced stability. Long-term stability and reproducibility with relative standard deviations of less than 5 % for the peak current (n=20) were also demonstrated. The simplicity and significant performance exhibited by the CNT/PMMA composite electrode indicate great promise for conventional CE, flowing-injection analysis, and other microfluidic analysis systems.

Nanomaterials as electrochemical detectors in microfluidics and CE: Fundamentals, designs, and applications

“…See Fig. 2 for a comparison of the response and noise of CNT/PMMA detectors [50] for microfluidic systems. Several materials were used as binders of the CNT composites in order to fabricate detectors for electrophoretic systems.…”

“…Several materials were used as binders of the CNT composites in order to fabricate detectors for electrophoretic systems. These included mineral oil [46], PMMA [50,51], polystyrene [52], epoxy resin [53], and alginate [33]. The PMMA/CNT composite offers a distinct advantage because it enables integration of CNT-based electrodes into the body of PMMA microchips [50].…”

Facile Preparation of Carbon Nanotube/Poly(ethyl 2‐cyanoacrylate) Composite Electrode by Water‐Vapor‐Initiated Polymerization for Enhanced Amperometric Detection

“…Recently, a method based on in situ polymerization was developed for the fabrication of CNT/polymer composition electrodes as the end-column amperometric detectors of conventional and microchip capillary electrophoresis (CE). CNTs were mixed with the oligomers of epoxy, [19] methyl acrylate, [36] and styrene [37] and were filled into the inner bores of fused silica capillaries. After the CNT-containing mixtures were cured, CNT/polymer composite electrodes were obtained.…”

Carbon‐Nanotube–Alginate Composite Modified Electrode Fabricated by In Situ Gelation for Capillary Electrophoresis

“…Recently, we developed a method based on in situ polymerization to fabricate CNT-polymer composite electrodes as end-column amperometric detectors for conventional and microchip CE. CNTs were mixed with oligomers of epoxy, [15] methyl acrylate, [25] and styrene [26] and were inserted into the inner bores of fused silica capillaries. After the mixtures had cured, CNT-polymer composite electrodes were obtained.…”