Copper @ eggshell nanocomposite/chitosan gelified carbon paste electrode as an electrochemical biosensor for l-tyrosine analysis as biomarkers in the serum of normal and liver disease patients

L-Tyrosine (L-Tyr), an amino acid, has emerged as a potential biomarker for the detection and monitoring of liver cirrhosis (LC) and hepatocellular carcinoma (HCC). By analysing the serum levels of L-Tyr, healthcare professionals can gain insights into the progression and development of these liver diseases. The utilization of L-Tyr as a biomarker holds potential for early detection and timely intervention, improving patient outcomes and treatment options. In this study we developed a novel nanocomposite based on eggshell waste and copper nanoparticles to modify carbon paste electrode (CPE) using chitosan gel as a binder for sensitive estimation of L-Tyr in human serum samples. The use of chitosan gel avoids the insulating effect of paraffin oil that was usually used for fabrication of CPE and enhance the sensitivity and selectivity of the modified electrode. Square wave voltammetry (SWV) was used to optimize the electrochemical parameters of the oxidation of L-Tyr onto the surface of the fabricated electrode (CuNPs@ESh/CS/CPE). The prepared composite was characterized using X-ray diffraction (XRD), Fourier Transform − Infrared spectroscopy (FT-IR), UV–VIS spectroscopy and scan electron microscopy (SEM) and electrochemical impedence spectroscopy (EIS). The fabricated biosensor could estimate L-Tyr levels in controls, LC and HCC patients’ serum with high accuracy and sensitivity. The obtained results demonstrated the presence of significant difference in L-Tyr levels in the three studied groups. This indicates that L-Tyr amino acid may serve as a crucial biomarker for the evaluation of such liver diseases.