A microbead array chemical sensor using capillary-based sample introduction: toward the development of an "electronic tongue".
The development of a micromachined fluidic structure for the introduction of liquid samples into a chip-based sensor array composed of individually addressable polymeric microbeads is presented. The micromachined structure consists of micromachined storage cavities combined with a covering glass layer that confines the microbeads and fluidic channels. In our sensor array transduction occurs via optical (colorimetric and fluorescence) changes to receptors and indicator molecules that are covalently attached to termination sites on the polymeric microbeads. Spectral data are acquired for each of the individual microbeads using a charged-coupled device (CCD) allowing for the near-real-time analysis of liquid sample. Hence the micromachined fluidic structure must allow for both optical access to the microbeads and fluid flow through the micromachined cavities that serve as the microreactors/analysis chambers. One of the key parts of the structure is a passive fluid introduction system driven only by capillary force. This simple means of fluid introduction realizes a compact device. The capillary flow on the inlet channel has been studied, and the responses of the microbeads (alizarin complexone) to a liquid sample have been characterized. The test results show that this system is useful in a micro-total-analysis-system (mu-TAS) and biomedical applications.
Sohn
Young-Soo
YS
The University of Texas at Austin, Department of Electrical and Computer Engineering, Austin, TX 78712, USA. sohn.ys@mail.utexas.edu
Goodey
Adrian
A
Anslyn
Eric V
EV
McDevitt
John T
JT
Shear
Jason B
JB
Neikirk
Dean P
DP
D032701:Biomimetics / Q000295:instrumentation* / Q000379:methods; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D002197:Capillary Action; D020099:Coated Materials, Biocompatible / Q000032:analysis / Q000737:chemistry; D045424:Complex Mixtures / Q000032:analysis*; D046209:Electrophoresis, Microchip / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D046228:Microarray Analysis / Q000295:instrumentation* / Q000379:methods; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation / Q000379:methods; D008863:Microspheres; D013649:Taste / Q000502:physiology*; D014059:Tongue / Q000502:physiology*; D014159:Transducers
D020099:Coated Materials, Biocompatible; D045424:Complex Mixtures