Electrochemical detector integrated on microfabricated capillary electrophoresis chips
First Claim
1. In a microfabricated capillary electrophoresis chip including a substrate with an elongated separation channel with conductive means at each end of the channel for applying a separation voltage along the channel, the improvement comprising an integrated electrochemical detector having a thin film working electrode extending into said separation channel at or near the very end of said separation channel where the working electrode is close to ground potential and has minimal influence from the high electrophoresis potentials, in order to detect current generated by molecules undergoing redox reaction as they migrate past the thin film electrode after they have migrated the length of the channel, the portion of said thin film electrode extending into said channel being very narrow to minimize the electrophoresis voltage gradient which it senses, and a reference electrode spaced from said working electrode.
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Abstract
A microfabricated capillary electrophoresis chip which includes an integral thin film electrochemical detector for detecting molecules separated in the capillary.
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Citations
18 Claims
- 1. In a microfabricated capillary electrophoresis chip including a substrate with an elongated separation channel with conductive means at each end of the channel for applying a separation voltage along the channel, the improvement comprising an integrated electrochemical detector having a thin film working electrode extending into said separation channel at or near the very end of said separation channel where the working electrode is close to ground potential and has minimal influence from the high electrophoresis potentials, in order to detect current generated by molecules undergoing redox reaction as they migrate past the thin film electrode after they have migrated the length of the channel, the portion of said thin film electrode extending into said channel being very narrow to minimize the electrophoresis voltage gradient which it senses, and a reference electrode spaced from said working electrode.
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8. A microfabricated capillary electrophoresis chip including a substrate with an elongated separation channel and a cover plate mounted on said substrate to form, with said channel, a separation capillary comprising:
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thin film conductive means at each end of said capillary for applying a separation voltage along said capillary, and an electrochemical detector having a thin film working electrode near the very end of said channel where the working electrode is close to ground potential and has minimal influence from the high electrophoresis potentials, wherein the thin film working electrode is adapted to detect molecules undergoing redox reaction as they migrate past the thin film electrode, the portion of said thin film working electrode extending into said channel being narrow and near the end of said capillary to minimize the separation voltage gradient which is senses, and a reference electrode spaced from said working electrode. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. A microfabricated capillary electrophoresis chip including an etched glass substrate with an elongated separation channel and an injection channel and a cover plate mounted on said substrate to form, with said channels a separation and injection capillary comprising:
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thin film leads extending from the same edge of said chip to connect to the ends of the separation and injection channels, an integrated electrochemical detector having a thin film working electrode extending from said one edge into said separation channel at or near the very end of said channel where the working electrode is close to ground potential and has minimal influence from the high electrophoresis potentials, in order to detect current generated by molecules undergoing redox reaction as they migrate past the thin film electrode after they have migrated the length of the channels, the portion of said thin film electrode extending into said channel being narrow to minimize the electrophoresis voltage gradient which it senses, and a reference electrode spaced from said working electrode. - View Dependent Claims (16, 17, 18)
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Specification