Dielectric Detection Using Biochemical Assays - Point-of-Care Diagnostics on a Chip - page 92

Chapter 5
Dielectric Detection Using Biochemical Assays

Yang-Kyu Choi, Chang-Hoon Kim, Jae-Hyuk Ahn, Jee-Yeon Kim,
and Sungho Kim

Abstract Point-of-care (POC) diagnostics typically make use of labeling tech-
niques that employ fluorescent, chemiluminescent, redox, or radioactive probes.
Although such methods provide high sensitivity, they are complicated because their
labeling steps require a significant amount of time and labor in their execution
and in the analysis of their results. Thus, the portability, which is meant to
be the primary advantage of POC systems, is sacrificed. The use of electronic
devices for POC systems circumvents this problem, enabling label-free detection,
miniaturization, and low costs. Label-free detection is made possible by direct
electrical measurement of the sample molecules, which works by monitoring
changes in their intrinsic electrical properties. Miniaturization and the integration of
sensors and readout circuitry have been enabled by industrialized microfabrication
technology. By integrating the sensors and circuitry onto a monolithic substrate, the
fabrication cost can be remarkably reduced.

5.1 Introduction

Point-of-care test (POCT) systems have shown great promise as diagnostic tech-
niques that provide fast, convenient results at or near the site of patient care [ 1 ].
These methods, which are widely used, often involve labeling techniques that
employ fluorescent, chemiluminescent, redox, or radioactive probes [ 2 ]. Although
such methods provide high sensitivity, they are complicated because their labeling
steps require a significant amount of time and labor in their execution and in
the analysis of their results. A transducer that converts a molecular signal to an
electrical signal is an indispensible part of the aforementioned approaches, but

Y.-K. Choi ( ) S. Kim

Department of Electrical Engineering, Korea Advanced Institute of Science and Technology,
Daejeon, Republic of Korea
e-mail: [e-mail]

C.-H. Kim J.-H. Ahn J.-Y. Kim