Electrochemical impedance study on nanofibers of poly(m-anthranilic acid)/polyacrylonitrile blends

Electrochemical impedance and spectroscopy study of the EDC/NHS activation of the carboxyl groups on poly(ε-caprolactone)/poly(m-anthranilic acid) nanofibers

“…P3ANA in the PCL/P3ANA nanofibers displays the peaks at 2615, 1690, 1580 and 1510 cm -1 which were attributed to O-H stretching, C=O stretching, C=C stretching and N-H stretching, respectively. The peaks at 1250 and 1070 cm -1 were attributed to C-N stretching [8,26]. The carboxyl groups on P3ANA provide active sites for albumin binding through forming succinimidyl ester (-COOSuc) by reacting with NHS, in the presence of EDC [7].…”

“…In Nyquist plot (Figure 9), albumin immobilized PCL/P3ANA nanofibers exhibited a semicircle while PCL/P3ANA nanofibers showed a linear behaviour. The diameter of the semicircle of Nyquist plot represents the charge-transfer resistance (R ct ) [8] and linear line with high-slope indicates capacitive behavior [36]. Nanofibers became resistive after treated with albumin and the chargetransfer resistance of the albumin immobilized nanofibers was increased.…”

“…Moreover, negatively charged ions can be repulsed by albumin on the surface and the transfer of positively charged and relatively big ions into positively charge nanofibers become challenging [24]. Q represents the constant phase element (CPE) which was applied in the equivalent circuit for the simulation of the impedance data, since CPE takes into account the non-homogeneity of the conductance [8] and the electrode [38]. The impedance of a non-ideal electrode is defined by the formula (Z CPE = T CPE (jw) -n ) where T CPE and n are frequency-independent constants; w is the angular frequency [35], n is a parameter describing the deviation from an ideal capacitor and arises from the slope of the log Z versus log f plot.…”

“…Poly(manthranilic acid) (P3ANA) is a very convenient conductive polymer for immobilization of biomolecules covalently due to the presence of carboxylic acid group -COOH on the main polyaniline backbone [8]. Covalent immobilization of the biomolecules by using reactive groups has been recognized as an attractive strategy since it provides the control of the immobilization of biological probes on the surface [9].…”

“…The nanofibers become resistive due to albumin immobilization. The obtained data revealed that electrochemical impedance spectroscopy can be used for investigation of surface modification with biomolecule immobilization by the determina- Poly(m-anthranilic acid) (P3ANA) was synthesized according to our previous study [8]. Briefly, 3-aminobenzoic acid (0.043 mol) has been dissolved in 90 mL of 0.5 M NaOH.…”