Sensitivity Improvement of an Impedimetric Immunosensor Using Functionalized Iron Oxide Nanoparticles

<table class="table-group" width="800px"><tr class="fig-image" id="a"><td><img alt="746548.fig.0012a" src="https://static.hindawi.com/articles/js/volume-2009/746548/figures/746548.fig.0012a.jpg"/></td></tr><tr class="fig-caption"><td align="center"><table><tr><td><b>(a) </b>Detection using system 1 based on SAM</td></tr></table></td></tr><tr class="fig-image" id="b"><td><img alt="746548.fig.0012b" src="https://static.hindawi.com/articles/js/volume-2009/746548/figures/746548.fig.0012b.jpg"/></td></tr><tr class="fig-caption"><td align="center"><table><tr><td><b>(b) </b>Detection using system 2 based on iron oxide nanoparticles</td></tr></table></td></tr></table>

<table>Nyquist diagram (−Im(<svg height="8.4250002" id="M130" style="vertical-align:-0.273pt" version="1.1" viewbox="0 0 8.5874996 8.4250002" width="8.5874996" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g transform="matrix(.017,-0,0,-.017,.062,8.013)"><path d="M475 445l-64 -69q-119 -128 -289 -280q27 6 81 -15q66 -26 102 -26q48 0 111 93l23 -19q-41 -84 -75.5 -116.5t-73.5 -32.5q-37 0 -147 53q-43 21 -63 7q-22 -15 -38 -41q-4 -7 -11 -7q-8 10 -8 26q0 38 47 83l292 273q-32 -5 -67 -1q-63 7 -105 7q-32 0 -53.5 -22
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</svg>) versus Re(<svg height="8.4250002" id="M131" style="vertical-align:-0.273pt" version="1.1" viewbox="0 0 8.5874996 8.4250002" width="8.5874996" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g transform="matrix(.017,-0,0,-.017,.062,8.013)"><path d="M475 445l-64 -69q-119 -128 -289 -280q27 6 81 -15q66 -26 102 -26q48 0 111 93l23 -19q-41 -84 -75.5 -116.5t-73.5 -32.5q-37 0 -147 53q-43 21 -63 7q-22 -15 -38 -41q-4 -7 -11 -7q-8 10 -8 26q0 38 47 83l292 273q-32 -5 -67 -1q-63 7 -105 7q-32 0 -53.5 -22
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</svg>)) at −400 mV versus SCE in PBS solution  10 mM pH 7.4, obtained for the non-Faradic impedance measurement on modified gold electrode with biotin tagged reduced antibody under various concentrations of antigen. </table>

Journal of Sensors

fig12

Figure 12

Figure 12: Sensitivity Improvement of an Impedimetric Immunosensor Using Functionalized Iron Oxide Nanoparticles 