A novel microfluidic biosensor based on an electrical detection system for alpha-fetoprotein.
Conventional immunoassays are labor intensive, expensive and time consuming and require large pieces of equipment for detection. Therefore, we have developed and characterized a novel immunoassay methodology comprised of microbeads and microbiochips. In this method, microbeads are used to filter and immobilize antibodies and an immuno-gold silver staining (IGSS) method is then used to amplify electrical signals that correspond to the bound antibodies. The chip used for this system is composed of an inexpensive and biocompatible polydimethylsiloxane (PDMS) layer over a Pyrex glass substrate that contains a platinum (Pt) microelectrode, which is used to detect the electrical signal in this system, the microelectrode is fabricated on the substrate and a microchannel and pillar-type microfilter is formed in the PDMS layer. A sandwich immunoassay approach was applied to detect alpha-fetoprotein (AFP), a cancer biomarker, using this system. The results of this study showed that the time required for a complete assay was reduced by 1h and a detection limit as low as 1 ng/mL was attained when this system used, which indicates that similar bead-based electrical detection systems could be used for the diagnosis of many forms of cancer.
Maeng
Joon-Ho
JH
Department of Biochemistry, Graduate School, Hanyang University, Ansan, Gyeonggi-do 426-791, Republic of Korea.
Lee
Byung-Chul
BC
Ko
Yong-Jun
YJ
Cho
Woong
W
Ahn
Yoomin
Y
Cho
Nahm-Gyoo
NG
Lee
Seoung-Hwan
SH
Hwang
Seung Yong
SY
D015374:Biosensing Techniques / Q000379:methods*; D007118:Immunoassay; D046210:Microfluidic Analytical Techniques / Q000379:methods*; D013997:Time Factors; D000509:alpha-Fetoproteins / Q000032:analysis*
D000509:alpha-Fetoproteins