Insight into the sensing mechanism of an impedance based electronic tongue for honey botanic origin discrimination
; Lyoussi, B.
; Anjos, O.
; Estevinho, L.
; Miguel, M.
Sensors and Actuators, B: Chemical Vol. 285, Nº NA, pp. 24 - 33, April, 2019.
ISSN (print): 0925-4005
Scimago Journal Ranking: 1,63 (in 2019)
Digital Object Identifier: 10.1016/j.snb.2019.01.023
An impedance based electronic tongue was developed and used to discriminate honey of different botanic origin.The e-tongue presented here is based on the small-signal frequency response of the electrical double-layer es-tablished between the honey solution and an array of four different sensing units composed by gold, carbon,indium-tin-oxide, and doped silicon. The ability of the e-tongue to discriminate honey of differentfloral originswas demonstrated by distinguishing honey fromBupleurumandLavandulapollen prevalence. The honeyfin-gerprint obtained with the e-tongue was validated by parallel melissopalenogical analysis and physico-chemicalmethods. It is demonstrated that the e-tongue is very sensitive to changes on the honey electrical conductivity.Small differences in electrical conductivity are introduced by the presence of ionisable organic acids and mineralsalts. Moreover, we propose that the sensitivity of the tongue to changes in electrical conductivity can be ex-plored to probe other complex liquid substances.