Formation of the biorecognition layers within microfluidic sensor channels must be done after the completion of the channel structure since these layers cannot withstand the wafer bonding temperature. We propose a new post-bonding immobilization process to prepare the enzyme layers within microfluidic channels of electrochemical biosensors. An array of Pt vertical electrodes is electroplated using a SU-8 mold. The cured SU-8 is then removed by plasma etching to expose the Pt electrode and to define the fluidic channel cavity simultaneously. An array of enzyme posts is formed on the Pt surface by either electropolymerizing or photopolymerizing enzyme precursor solutions injected into the channel. Very little report is available about the reactive ion etching (RIE) of SU-8 that is the most critical step in this process. A systematic investigation on the RIE of SU-8 is conducted to obtain the maximum etch rate (1.2 ¿m/min.) based on different combinations of parameters of CF4 and O2 gas flow, RF power and time.

Meeting Name

5th IEEE Conference on Sensors, 2006


Electrical and Computer Engineering

Second Department

Chemical and Biochemical Engineering

Third Department

Materials Science and Engineering


National Science Foundation (U.S.)
University of Missouri--Rolla. Intelligent Systems Center

Keywords and Phrases

Biorecognition Layers; Enzyme Layers; Microfluidic Sensor Channels; Biosensors

Document Type

Article - Conference proceedings

Document Version

Final Version

File Type





© 2007 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Jan 2007