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Time response and stability of porous silicon capacitive immunosensors

DSpace at IIT Bombay

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Title Time response and stability of porous silicon capacitive immunosensors
 
Creator BETTY, CA
LAL, R
YAKHMI, JV
KULSHRESHTHA, SK
 
Subject biosensor
porous silicon
capacitive immunosensor
time dependent response
stability issues
specific and nonspecific analyte-antibody interactions
 
Description The time response of affinity sensors made with nanostructured materials is a topic of considerable interest, since affinity sensors made with nanostructured materials provide greater sensitivities than corresponding planar crystalline devices but at the cost of stability and drift. We present a study of the time response of capacitive immunosensors made using porous silicon and ultrathin room temperature anodic oxide. It was found that sensor drift can be substantial but can be reduced by subjecting the capacitive immunosensor in buffer to an anodic bias that is larger than the bias at which sensor capacitance is measured. By measuring sensor response before the addition of the analyte and using it for baseline correction after addition of the analyte, the effect of nonspecific sensor drift can be further reduced. We observed that after the addition of the analyte to the porous silicon immunocapacitor, there is a fast decrease in capacitance (order of tens of seconds) followed by a slow increase (order of tens of minutes), which models well as a sum of exponents with a fast exponential decay followed by a slow exponential rise. Possible processes that can give rise to such a response are perturbations of the double layer for the fast decay and column resistance switching for the slow rise. (c) 2006
 
Publisher ELSEVIER ADVANCED TECHNOLOGY
 
Date 2011-07-21T16:01:10Z
2011-12-26T12:52:04Z
2011-12-27T05:39:03Z
2011-07-21T16:01:10Z
2011-12-26T12:52:04Z
2011-12-27T05:39:03Z
2007
 
Type Article
 
Identifier BIOSENSORS & BIOELECTRONICS, 22(6), 1027-1033
0956-5663
http://dx.doi.org/10.1016/j.bios.2006.04.022
http://dspace.library.iitb.ac.in/xmlui/handle/10054/5917
http://hdl.handle.net/10054/5917
 
Language en