TY - JOUR
T1 - ZnO nanorods as immobilization layers for interdigitated capacitive immunosensors
AU - Sanguino, P.
AU - Monteiro, Tiago
AU - Bhattacharyya, S. R.
AU - Dias, C. J.
AU - Igreja, Rui
AU - Franco, Ricardo
N1 - This work was supported by Fundação para a Ciência e a Tecnologia, Portugal (Grants PEstC/EQB/LA0006/2013 to PS and RF; PTDC/CTM-NAN/112241/2009 to RF; post-doc grant SFRH/BPD/70803/2010 to PS; post-doc grant SFRH/BPD/66773/2009 to SRB; and the COMPETE Program).
PY - 2014/12/1
Y1 - 2014/12/1
N2 - ZnO nanorod structures were deposited on micrometer interdigitated Au electrodes to function as three-dimensional matrixes for the immobilization of antibodies in a capacitive immunosensor format. As a proof of concept, anti-horseradish peroxidase (anti-HRP) antibodies were immobilized on the ZnO nanostructured surface by a crosslinking process. The ZnO nanorod layer allows distribution of antibodies across the entire region probed by the measuring electric field applied to the microelectrodes. This is an alternative approach to the use of more expensive nanometer electrodes necessary in the detection of smaller layers of antibodies. The new micrometer interdigitated capacitive immunosensor was able to discriminate between HRP antigen in buffer; a non-specific antigen in buffer; or buffer alone, as proven by capacitance measurements. Maximum response of the sensor was achieved in the 5-6 kHz frequency range, opening the possibility for a simplified single frequency detection system for direct antigen detection in complex biological samples.
AB - ZnO nanorod structures were deposited on micrometer interdigitated Au electrodes to function as three-dimensional matrixes for the immobilization of antibodies in a capacitive immunosensor format. As a proof of concept, anti-horseradish peroxidase (anti-HRP) antibodies were immobilized on the ZnO nanostructured surface by a crosslinking process. The ZnO nanorod layer allows distribution of antibodies across the entire region probed by the measuring electric field applied to the microelectrodes. This is an alternative approach to the use of more expensive nanometer electrodes necessary in the detection of smaller layers of antibodies. The new micrometer interdigitated capacitive immunosensor was able to discriminate between HRP antigen in buffer; a non-specific antigen in buffer; or buffer alone, as proven by capacitance measurements. Maximum response of the sensor was achieved in the 5-6 kHz frequency range, opening the possibility for a simplified single frequency detection system for direct antigen detection in complex biological samples.
KW - Biosensor
KW - Capacitive immunosensor
KW - Impedance spectroscopy
KW - Interdigitated electrodes
KW - ZnO nanorods
UR - http://www.scopus.com/inward/record.url?scp=84906316014&partnerID=8YFLogxK
U2 - 10.1016/j.snb.2014.06.141
DO - 10.1016/j.snb.2014.06.141
M3 - Article
AN - SCOPUS:84906316014
SN - 0925-4005
VL - 204
SP - 211
EP - 217
JO - Sensors and Actuators B: Chemical
JF - Sensors and Actuators B: Chemical
ER -