Hydroxyapatite/L-Lysine Composite Coating as Glassy Carbon Electrode Modifier for the Analysis and Detection of Nile Blue A

Jimmy Julio Kouanang Ngouoko; Kevin Yemele Tajeu; Ranil Clément Tonleu Temgoua; Giscard Doungmo; Ingo Doench; Arnaud Kamdem Tamo; Théophile Kamgaing; Anayancy Osorio-Madrazo; Ignas Kenfack Tonle

doi:10.3390/ma15124262

Hydroxyapatite/L-Lysine Composite Coating as Glassy Carbon Electrode Modifier for the Analysis and Detection of Nile Blue A

Materials (Basel). 2022 Jun 16;15(12):4262. doi: 10.3390/ma15124262.

Authors

Affiliations

¹ Department of Chemistry, Faculty of Science, University of Dschang, Dschang P.O. Box 67, Cameroon.
² Higher Teacher Training College, University of Yaoundé 1, Yaoundé P.O. Box 47, Cameroon.
³ Institute of Inorganic Chemistry, Christian-Albrechts-Universität zu Kiel, Max-Eyth-Straβe 2, 24118 Kiel, Germany.
⁴ Laboratory for Bioinspired Materials BMBT, Institute of Microsystems Engineering IMTEK-Sensors, University of Freiburg, 79110 Freiburg, Germany.
⁵ Freiburg Center for Interactive Materials and Bioinspired Technologies FIT, University of Freiburg, 79110 Freiburg, Germany.
⁶ Freiburg Materials Research Center FMF, University of Freiburg, 79104 Freiburg, Germany.

Abstract

An amperometric sensor was developed by depositing a film coating of hydroxyapatite (HA)/L-lysine (Lys) composite material on a glassy carbon electrode (GCE). It was applied for the detection of Nile blue A (NBA). Hydroxyapatite was obtained from snail shells and its structural properties before and after its combination with Lys were characterized using X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) surface area analyses. The coupling of Lys to HA was attributed to favorable interaction between negatively charged -COO^- groups of Lys and divalent ions Ca²⁺ of HA. Electrochemical investigations pointed out the improvement in sensitivity of the GCE/Lys/HA sensor towards the detection of NBA in solution. The dependence of the peak current and potential on the pH, scan rate, and NBA concentration was also investigated. Under optimal conditions, the GCE/Lys/HA sensor showed a good reproducibility, selectivity, and a NBA low detection limit of 5.07 × 10^-8 mol L^-1. The developed HA/Lys-modified electrode was successfully applied for the detection of NBA in various water samples.

Keywords: Nile blue A; electrochemical analysis; electrode coating; glassy carbon electrode; hydroxyapatite; inorganic–organic composite; lysine.

Abstract

Grants and funding