Nafion® Coated Electropolymerised Flavanone‐based pH Sensor

Abstract

This work summarizes the electrochemical response of flavanone carbon composite electrodes in comparison with Nafion ® -coated flavanone carbon composite electrodes, for use as voltammetric pH sensors in both buffered and low-buffered media. Square wave voltammetric measurements suggest the peak potential achieved from the electrochemical polymerization after the electron-proton oxidation responds with accuracy to buffered pH solutions for both coated and non-coated electrodes, with a potential shift of 55.1 mV and 54.6 mV per pH unit respectively. However, a considerable improvement in stability, accuracy and sensitivity is provided by the proton-transfer Nafion ® layer in CO 2 bubbled sea water. Furthermore, Nafion ® -coated flavanone carbon composite electrodes predicted a pH of 8.04 for the commercial seawater, which is in excellent agreement with the measured pH 8.05 value.

Moving towards in pouch diagnostics for ostomy patients: exploiting the versatility of laser induced graphene sensors

“…It is noteworthy that Srinivas et al (2022) also observed a similar non Nernstian (2H + /3e − ) behaviour (45 mV) with a carbazole-quinone derivative and attributed the response to the orientation/interaction of the redox probe on the surface [ 70 ]. The change in behaviour upon being surface confined is supported by the work by Lee et al (2013) where the pKa and hence protonation of the redox species can be modified by the surface interactions [ 73 ]. Nevertheless, it can be seen from Table 2 that while the sensitivity of the probe may be reduced, the accuracy is retained.…”

Fabrication and Optimization of Nafion as a Protective Membrane for TiN-Based pH Sensors

“…Nafion’s strong ionic conductivity, cation selectivity, chemical inertness, and thermal stability make it a well-known ionic polymer [ 18 ]. Significant interest in the special features of Nafion has been shown in numerous research fields and applications, such as fuel cells and batteries [ 19 ], chemical sensors [ 20 ], biosensors [ 21 , 22 , 23 ], and medical diagnosis technologies [ 24 , 25 ].…”