Novel iron (III) phthalocyanine derivative functionalized semiconductor based transducers for the detection of citrate

© 2016 Elsevier B.V. All rights reserved. In the present work, we report a novel citrate-selective sensor based on iron (III) phthalocyanine chloride-C-monoamido-Poly-n-Butyl Acrylate (Fe(III)MAPcCl-P-n-BA) modified silicon nitride and Ion sensitive field effect transistor (ISFET) structures for the electrochemical determination and estimation of the pathophysiological range of citrate. The developed capacitive sensor based on Fe(III)MAPcCl-P-n-BA had a Nernstian sensitivity of (-20.2 ± 1.3) mV/decade with a detection limit of about 7 × 10-7 M and a linear range from 10-6 M to 10-1 M (RSD = 6.2%). Then, the performance of the Fe(III)MAPcCl-P-n-BA functionalized ISFET structure towards the detection of citrate has been investigated. A Nernstian sensitivity of about (-19.8 ± 1.0) mV/decade in the range from 10-6 M to 10-1 M was achieved (RSD = 4.8%) which covered the pathologically important clinical range of citrate. The detection limit was about 4 × 10-7 M. The number of available recognition sites Ns and the complexation constant pK were calculated using the enhanced site binding model. A side by side comparison of the developed chemical sensors based on electrolyte-insulator-Semi conductor (EIS) and ISFET structures showed similar characteristics which proves the successful miniaturization of the semiconductor based transducer. The obtained experimental data of the Fe(III)MAPcCl-P-n-BA functionalized ISFET structure were used to validate the TopSPICE ISFET/MEMFET macromodel. The obtained theoretical sensitivity was in good agreement to the experimental one which proves the successful design of the developed ISFET/MEMFET macromodel.