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

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.

A novel non-enzymatic electrochemical uric acid sensing method based on nanohydroxyapatite from eggshell biowaste immobilized on a zinc oxide nanoparticle modified activated carbon electrode (Hap-Esb/ZnONPs/ACE)

“…The ZnO NPs were indicated with white dots. From 33,[66][67][68] There are several factors that can cause agglomeration are (1) shear forces between particles, (2) initial density, (3) moisture, (4) sintering temperature, and (5) particle size. [69][70][71][72] In this work, the synthesis procedure of Hap-Esb and the preparation of the developed electrode include grinding, wetting, and drying processes, possibly causing the agglomeration.…”

“…The surface morphology of Hap-Esb/ZnONPs/ACE is depicted in Fig.4(c). As shown, white and cloudy particles are submicron in size and connected one to another, indicating an agglomeration of Hap-Esb particles 33,[66][67][68]. There are several factors that can cause agglomeration are (1) shear forces between particles, (2) initial density, (3) moisture, (4) sintering temperature, and (5) particle size [69][70][71][72].…”

“…The (OH-) ions appear to play a signicant role in electrochemistry thereby increasing the current response (reduction). [32][33][34][35][36][37] Therefore, Hap could be used for the detection of UA with further modication of the electrode surface by applying a semiconductor material to improve the current response.…”

Electrochemical detection of sulfite in food samples

“…Since they exhibit lower residual current in the ranges of close to 1 V in aqueous media as well as more extended ranges in organic solvents and aqueous micellar solution, they are usually utilized as one of the indicator electrodes. Moreover, numerous papers of the GCEs exhibited higher sensitivity of the apparent rates of redox reactions toward the electrode surface state [124][125][126][127][128][129][130][131].…”

Fabrication of an Organofunctionalized Talc-like Magnesium Phyllosilicate for the Electrochemical Sensing of Lead Ions in Water Samples

“…The Quantification of lead in real samples is usually performed by electrothermal atomic absorption spectrometry [ 28 ], atomic fluorescence spectrometry [ 29 ], inductively coupled plasma spectrometry [ 30 ]. As these methods are somewhat limited in selectivity and sensitivity, electrochemical methods have been widely studied as electrochemical sensors [ 31 , 32 ]. In this regard, several works based on chemically modified electrode materials have been proposed [ 33 , 34 , 35 , 36 , 37 , 38 ].…”