A voltammetric pH sensor for food and biological matrices

0531445 - ÚFCH JH 2021 RIV CH eng J - Journal Article
Vivaldi, F. - Santalucia, D. - Poma, N. - Bonini, A. - Salvo, P. - Del Noce, L. - Melai, B. - Kirchhain, A. - Kolivoška, Viliam - Sokolová, Romana - Hromadová, Magdaléna - Di Francesco, F.
A voltammetric pH sensor for food and biological matrices.
Sensors and Actuators B - Chemical. Roč. 322, NOV 2020 (2020), č. článku 128650. E-ISSN 0925-4005
Institutional support: RVO:61388955
Keywords : pH sensor * voltammetric sensor * indoaniline derivative
OECD category: Electrochemistry (dry cells, batteries, fuel cells, corrosion metals, electrolysis)
Impact factor: 7.460, year: 2020
Method of publishing: Limited access

Measurement of pH is of fundamental importance in a wide range of environmental, biological and industrial applications. Glass electrode and litmus paper are widely used for this, but the former is difficult to miniaturize, prone to drift and fragile, the latter is inaccurate. This paper describes a pH sensor based on an indoaniline-derivative (4-((4-aminophenyl)imino)-2,6-dimethoxycyclohexa-2,5-dien-1-one), which exploits alternating current voltammetry to measure pH in the range between 2 and 12. The synthetized indoaniline-derivative was not genotoxic (A. cepa assay), and the sensor reliably measured pH in milk, tea, orange juice, blood, urine and saliva. Results were comparable with those obtained with a glass electrode calibrated with certified solutions (maximum relative standard deviation of 3 % and accuracy less than 0.2 pH unit). The sensor had negligible hysteresis, an almost Nernstian sensitivity (56 mV/pH) and was fully functional after a two-month storage. Sensor response showed a limited dependence on temperature (0.14 mV per pH unit and °C) and limited sensitivity to possible interferents such as lithium and sodium ions, its response to these was similar to that of a glass electrode, and was absent for ascorbic acid.
Permanent Link: http://hdl.handle.net/11104/0310110