TY - GEN
T1 - Highly sensitive immunoassays through dielectrophoresisbased protein enrichment using integrated nanorods
AU - Cao, Zhen
AU - Zhao, Jiongdong
AU - Liu, Yang
AU - Fu, Junxue
N1 - Funding Information:
This project was financially supported by the National Natural Science Foundation of China (Grant No. 61701438), the Fundamental Research Funds for the Central Universities, China (Grant No. 2017QNA5005) and the Hong Kong UGC General Research Fund HKBU 12300714.
PY - 2018
Y1 - 2018
N2 - Here, we present a novel insulator-based dielectrophoresis (DEP) device integrated with nanorod arrays for highly effective and rapid protein enrichment and detection. Dense arrays of Ag nanorods coated with oxide are fabricated on glass wafers prepatterned with microelectrodes; therefore creates a super high electric field gradient and concomitant adequate dielectrophoresis force for trapping of proteins. The fabrication process exploits oblique angle deposition (OAD), a physical vapor deposition method, for easy integration of nanostructures in DEP devices. This technique employs the shadowing effect and surface diffusion of adatoms, which eliminates the requirement of advanced lithography equipment. Leveraging on this platform, enrichment of bovine serum albumin (BSA) protein is demonstrated by 1800-fold with 180-fold/s when only applying 5 V electric potential at 1MHz. Further, the immunoassay of a tumor biomarker, carcinoembryonic antigen (CEA), with femtomolar sensitivity (~7.5 fM) is realized using this platform, referring to a 4,300-fold enhancement in the detection limit compared with identical assays performed on blank glass plates. The enrichment of proteins also accelerates the binding kinetics and enables signal saturation within one minute.
AB - Here, we present a novel insulator-based dielectrophoresis (DEP) device integrated with nanorod arrays for highly effective and rapid protein enrichment and detection. Dense arrays of Ag nanorods coated with oxide are fabricated on glass wafers prepatterned with microelectrodes; therefore creates a super high electric field gradient and concomitant adequate dielectrophoresis force for trapping of proteins. The fabrication process exploits oblique angle deposition (OAD), a physical vapor deposition method, for easy integration of nanostructures in DEP devices. This technique employs the shadowing effect and surface diffusion of adatoms, which eliminates the requirement of advanced lithography equipment. Leveraging on this platform, enrichment of bovine serum albumin (BSA) protein is demonstrated by 1800-fold with 180-fold/s when only applying 5 V electric potential at 1MHz. Further, the immunoassay of a tumor biomarker, carcinoembryonic antigen (CEA), with femtomolar sensitivity (~7.5 fM) is realized using this platform, referring to a 4,300-fold enhancement in the detection limit compared with identical assays performed on blank glass plates. The enrichment of proteins also accelerates the binding kinetics and enables signal saturation within one minute.
KW - Dielectrophoresis
KW - Immunoassay
KW - Oblique angle deposition
KW - Protein enrichment
UR - http://www.scopus.com/inward/record.url?scp=85079882715&partnerID=8YFLogxK
M3 - Conference proceeding
AN - SCOPUS:85079882715
T3 - 22nd International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2018
SP - 358
EP - 361
BT - 22nd International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2018
PB - Chemical and Biological Microsystems Society
T2 - 22nd International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2018
Y2 - 11 November 2018 through 15 November 2018
ER -