Calcium Carbonate Originating from Snail Shells for Synthesis of Hydroxyapatite/L-Lysine Composite: Characterization and Application to the Electroanalysis of Toluidine Blue

Snail shells (Anadora Fulica) calcined at different temperatures were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, thermal analyses (TG-DTG), scanning electron microscopy (SEM) and N2 adsorption–desorption experiments (surface area measurements found using the coupled BET/BJH method). The principal objective was to identify forms of calcium carbonate hydroxide in snail as raw materials. thus obtained used synthesis hydroxyapatite/L-lysine (HA/Lys) composite. composite chemically modify a glassy carbon electrode (GCE) cyclic voltammetry (CV) electrochemical impedance spectroscopy (EIS). It appeared that developed sensor Lys/HA/GCE facilitated electronic transfer compared pristine electrode. In strongly acid medium, this surface protonated therefore became positively charged, which allowed it have good affinity with [Fe(CN)6]3-. An application toluidine blue (TB) electroanalysis phosphate buffer carried out. Optimal performances differential pulse (DPV). performance determined concentration range 1 10 µM TB, limit detection (LOD) S/N = 3 method 2.78 × 10?7 M. also detect TB spring water 96.79% recovery.