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

Abstract

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

Effect of Calcination Temperature on the Powder of Freshwater Snail Shells (Sulcospira testudinaria) Properties

“…Vibration modes of the CO 3 2− ion in the powder are marked by absorptions at wave numbers of 1082 cm -1 (𝜈 1 ), 864 cm -1 (𝜈 2 ), 1426 cm -1 (𝜈 3 ), 1780 cm -1 (𝜈 3 ), and 708 cm -1 (𝜈 4 ). Similar absorption peak observations have also been reported in reference [10] indicating the typical vibration modes of aragonite as a crystalline form of CaCO3. Additionally, the FTIR spectra display a combination of CO 3 2− vibration bands observed at 2520 cm -1 and 2918 cm -1 [11] Furthermore, the hydroxyl group from water is observed in a broad band with a peak at 3300 cm -1 [12].…”

“…The calcination process changes 69% of CaCO3 into the calcite phase (marked by the green box) at 500°C [Figure 5(b)], increasing to 96.7% at 700°C [Figure 5(c)], and reaching an optimum of 97% at 800°C (XRD spectrum not displayed). These crystalline phases have sharp peaks at 2𝜃 corresponding to data reported for CaCO3 [10].…”

Biomimetic Use of Food-Waste Sources of Calcium Carbonate and Phosphate for Sustainable Materials—A Review

“…Another biomaterial application with snail shell powder concerned the production of HA/l-lysine composites. These composites were employed to modify a carbon glassy electrode and effectively improved electronic transfer, as verified by using it in the electroanalysis of toluidine blue in water [53]. More evolved applications in geometrical terms have been also attempted to synthetize HA nanorods from snail shells, which would ease implantation; this was obtained by microwave irradiation through a suitable chelating Another biomaterial application with snail shell powder concerned the production of HA/l-lysine composites.…”

“…More evolved applications in geometrical terms have been also attempted to synthetize HA nanorods from snail shells, which would ease implantation; this was obtained by microwave irradiation through a suitable chelating Another biomaterial application with snail shell powder concerned the production of HA/l-lysine composites. These composites were employed to modify a carbon glassy electrode and effectively improved electronic transfer, as verified by using it in the electroanalysis of toluidine blue in water [53]. More evolved applications in geometrical terms have been also attempted to synthetize HA nanorods from snail shells, which would ease implantation; this was obtained by microwave irradiation through a suitable chelating agent, based on ethylenediaminetetraacetic acid (EDTA) [54].…”

Ferromagnetic Biochar Prepared from Hydrothermally Modified Calcined Mango Seeds for Fenton-like Degradation of Indigo Carmine

“…These chemicals currently occupy an important place in the industrial sector. They are widely used in the paper, cosmetic, food and textile industries [1][2][3][4][5]. The continued release of these recalcitrant compounds into the environment leads to long-term accumulation in the ecosystem.…”