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

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 x 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 x 10(-7) M. The number of available recognition sites N-s 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. (C) 2016 Elsevier B.V. All rights reserved.