by Keyword: Potentiometric

Hidouri S, Errachid AH, Baussels J, Korpan YI, Ruiz-Sanchez O, Baccar ZM, (2021). Potentiometric sensing of histamine using immobilized enzymes on layered double hydroxides Journal Of Food Science And Technology-Mysore 58, 2936-2942

Diamine oxydase and peroxidase have been co-immobilized onto layered double hydroxide (LDH) thin films for the development of real-time histamine biosensors. The chosen LDH materials are Mg2AlCO3, Mg4FeCl and Ca2AlCl. Prepared bi-enzymatic hybrid nanomaterials are capable of detecting histamine through the electrochemical oxidation of H(2)O(2)and are used as the sensitive membrane for potentiometric microelectrode. Histamine biosensors developed in this work have fast response of less than 20 s, are sensitive and selective, with a large dynamic range of 10(-8)-10(-3) M and a limit of detection of less than 10(-8) M. The detection limit of the developed bi-enzymatic biosensors is relatively higher than those corresponding with gas and liquid chromatography, which are still considered as the reference methods. Finally, the reproducibility, the specificity and the storage stability of the biosensors were studied.

JTD Keywords: Biogenic-amines, Biosensor, Diamine oxidase, Film, Fish, Histamine, Hybrid nanomaterial, Immobilization, Layer double hydroxide, Potentiometric biosensor, Specificity

de Oliveira, I. A. M., Risco, D., Vocanson, F., Crespo, E., Teixidor, F., Zine, N., Bausells, J., Samitier, J., Errachid, A., (2008). Sodium ion sensitive microelectrode based on a p-tert-butylcalix[4]arene ethyl ester Sensors and Actuators B: Chemical 130, (1), 295-299

Planar sodium-selective potentiometric microelectrodes with a conducting polymer (polypyrrole doped with cobaltabis(dicarbollide) ions ([3,3'-Co(1,2-C2B9-H-11)(2)](-))) as solid contact layer between the polymeric sensitive membrane and the platinum substrate have been constructed. The p-tert-butylcalix[4]arene ethyl ester was used as ionophore for sodium recognition. The microelectrode shows a linear response for Na+ concentrations between 3.0 x 10(-6) and 1.0 x 10(-1) M with a Nernstian slope of 58.65 +/- 2 mV per decade and a detection limit of 1.45 x 10(-6) M. The response time was 14 s, and the electrode is suitable for use within the pH range of 3-10.

JTD Keywords: Sodium, Polypyrrole, Calix[4]arene, Solid-state ion selective microelectrode, Potentiometric