A2

Chemical Sensors with Nanostructured Transducer Array

 

Chemical and electrochemical sensors are everywhere, from simple pH sensors to the sophisticated electronic nose. In fact, many types of biological sensors are also regarded as chemical sensors as they use a bioassay to translate a biological change to a chemical change. However, the science of molecular recognition is still not well understood. Many of today’s chemical sensors are limited in selectivity and sensitivity, i.e., the ability to discriminate between chemicals and the ability to resolve a small difference in concentration, respectively. This prevents them from serving many important applications requiring the detection of a very small, specific quantity within a mixture, for example the continuous monitoring of hormone levels in blood streams.

 

The goal of this project is to devise a design methodology for high-performance chemical and electrochemical sensors. Our approach is to combine the top-down fabrication technique of standard integrated circuits and the bottom-up technique of nano-fabrication. The combined approach takes advantage of the high level of integration from modern lithography and stellar sensing performance of nano-fabrication. Specifically, to build a fully integrated system (e.g., for cyclic voltammetry, amperometry and impedance spectroscopy), the signal processing and readout electronics will be fabricated using the complementary metal oxide semiconductor (CMOS) process. Then the selectivity and sensitivity of the sensor will be enhanced by introducing nanomaterials to the transducers using either surface-modification or self-assembly techniques.

 

Nanostructure integration directly addresses selectivity and sensitivity, which are of critical importance to chemical sensor performance.

 

Areas of study: chemical sensor design, nanostructuring, sensing materials

Supervisor: Dr. Derek HO (derekho@cityu.edu.hk; www.atomstosystems.com)

Suitable for: M.Phil./Ph.D.