Novel sensor structures for improved redox cycling

Introduction

Electrochemistry studies chemical reactions in which electrical charges or an electrical current are involved. An example of such reactions is the transformation of a certain ion 'A' into ion 'B' inside a solution. This reaction will take place if an electrode with a certain potential is present inside this solution. This transformation of ions from 'A' to 'B' can be reversed by a second electrode with the starting ion 'A' as resulting product. The whole transformation can now start over again and some sort of feedback loop is formed. This loop is called the redox cycling effect. It can be used to amplify measured signals in a chemical way. The higher the number of redox cycles, the higher the amplification of the measured signal will be. The redox cycling effect can be used to increase the selectivity of the sensor as well. To increase the selectivity, a proper choice of potentials has to be applied to the electrodes.

Project description

Inside the BIOS-chair a redox cycling amplification of up to 70x is achieved . Recent efforts were aimed at the design of a novel sensor structure which should reach even higher redox cycling amplification factors. The design of this sensor is finished, but a working sample has still to be fabricated.

Your goals inside this project are:

·	Fabrication of the novel sensor structure inside the Mesa+ cleanroom.

·	Perform measurements on the fabricated device to test its performance.

·	A theoretical study to predict selectivity of this sensor in a mixture of multiple redox-couples.

We offer:

·	Practical, on-hands experience in microfabrication inside the cleanroom.

·	Good support from the technicians of the BIOS-chair.

·	A practical assignment with the possibility to extend it with theoretical work.

Contact

Mathieu Odijk

BIOS-chair

University of Twente

P.O. Box 217

7500 AE Enschede

The Netherlands

Phone: +31 (0)53 489 4782

Fax: +31 (0)53 489 3595

Email: m.odijk@student.utwente.nl

dr. Wouter Olthuis