A novel sonogel-Leucine electrochemical sensor for the detection of neuroblastoma biomarker in human urine and synthetic cerebrospinal fluid
Mohamed Achache, Juan José García‐Guzmán, Nordin Ben Seddik, Laura Cubillana Aguilera, José María Palacios‐Santander, Dounia Bouchta, Mohamed Choukairi
Abstract
A new Sonogel-Carbon (SNGC) electrode modified with an amino acid (l-leucine; Leu) has been developed for the sensitive detection of homovanillic acid (HVA). Electrochemical properties of leucine-modified Sonogel-Carbon (SNGC-Leu) were characterized using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Comprehensive characterization using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier-transform infrared spectroscopy (FTIR), and powder X-ray diffraction (XRD) was conducted to investigate the structure of both SNGC-Leu and SNGC electrodes. The analytical performance of the SNGC-Leu sensor including the linear response range, repeatability, selectivity, and detection limit were examined. Differential pulse voltammetry (DPV) was employed to evaluate the analytical response in a linear concentration range of HVA from 0.5 μM to 50 μM, with a detection limit of 0.4 μΜ. Satisfactory reproducibility and repeatability (coefficient of variation (%RSD) < 3.5 %) were obtained. The SNGC-Leu sensor was successfully used to detect HVA in human urine and synthetic cerebrospinal fluid (CSF), exhibiting adequate recovery rates of 97.5-102 % and 96.3-106 %, respectively.