Zinc nitrate hexahydrate (Zn (NO
3)
2 · 6 H
2O) and aluminium nitrate nonahydrate (Al (NO
3)
3 · 9 H
2O), L-proline (BioUltra, 99.5%),
potassium permanganate (ACS),
iron (III) chloride,
glucose monohydrate,
L(+)-ascorbic acid, and
folic acid were supplied by Sigma-Aldrich (Steinheim, Germany).
Sodium hydroxide and 0.1 mol L
−1 pH 7 phosphate buffer solution (PBS) were from Fisher Scientific (Loughborough, UK), the uric acid and potassium chloride from Fluka BioChemika (Buchs, Switzerland), and the
sodium nitrite and
sodium nitrate (analytical grade) from Carlo Erba (Milan, Italy).
Silver paste was also used (Agar Scientific, Stansted Essex, England, UK, 60% solid silver in 4-methylpentan-2-one).
Tomassetti M., Pezzilli R., Prestopino G., Di Natale C, & Medaglia P.G. (2022). Novel Electrochemical Sensors Based on L-Proline Assisted LDH for H2O2 Determination in Healthy and Diabetic Urine. Sensors (Basel, Switzerland), 22(19), 7159.