## 1 Introduction  
The study of the biological properties of human diseases has been a subject of intense research in the field of infectious diseases (e.g., [1]). The study of human diseases has been a subject of intense research in the field of infectious diseases (e.g., [2]). The study of human diseases has been a subject of intense research in the field of infectious diseases (e.g., [3]). The study of human diseases has been a subject of intense research in the field of infectious diseases (e.g., [4]). The study of human diseases has been a subject of intense research in the field  
## 1 Introduction  
Hepatitis is one of the most dreadful diseases in the world, affecting millions of people every year and killing thousands per day [1]. There are at least five distinct hepatitis viruses from entirely different families, with all of them attacking the liver and causing hepatic inflammation. Among these, of the hepatitis A to E (HAV-HEV) viruses, the most harmful are the hepatitis B virus (HBV) and hepatitis C virus (HCV), as they can result in chronic infections, causing cirrhosis and ultimately cancer [1; 2]. To date, several methods have been developed and tested for the diagnosis of hepatitis. These methods include serological methods based on the identification of antibodies in the blood and immunological methods based on antigen-antibody interactions, including enzyme-linked immunosorbent assays (ELISA) and radioimmunoassays (RIAs) [3]. Further approaches include chemical methods, which are based on nucleic acid amplification, with the most renowned being polymerase chain reaction (PCR). All of these methods are laborious, time-consuming, and sometimes inaccurate [4]. The Rapid Diagnostic Tests (RTDs) which have recently been developed for hepatitis B and hepatitis C diagnosis are indeed considerably more rapid (20 min) and have a sensitivity of around 80%. A test kit based on a card strip is used, providing positive or negative results regarding the presence or absence of the disease. RTDs provide qualitative results only, however, with no detailed information about biomarkers, and furthermore require refrigeration, making it difficult to deploy them in remote areas. Non-destructive, reagent-free, portable approaches based on spectroscopy may provide huge benefits for the diagnosis of disease, along with detailed profiling of the biomolecules in a sample (including lipid, nucleic acid, and protein changes). Spectroscopic analyses, along with multivariate data mining techniques, including principal component analysis (PCA), partial least squares regression (PLSR), and partial least squares discriminant analysis (PLSDA), may provide valuable improvements in the diagnostic approaches [4]. Among the different types of vibrational spectroscopy, Fourier-transform infrared spectroscopy (FTIR) has great potential for the study of biomaterials, but it requires a detailed protocol to prepare and dry the samples [5]. The presence of water in a sample affects the IR signals by generating high-absorption water peaks and obscuring valuable information on the other molecules. Due to these limitations, among the types of vibrational spectroscopy, Raman spectroscopy (RS) is considered a better candidate for the study of biofluids and the diagnosis of hepatitis [6]. RS utilizes laser light scattered by molecular vibrations to sense the different moieties in an analyte and generate a unique spectral fingerprint [7]. RS is based on the inelastic scattering of monochromatic light, typically from a laser source [8]. When photons interact with a sample, most are elastically scattered (Rayleigh scattering), maintaining their original energy. However, a small fraction undergoes inelastic scattering, either gaining or losing energy due to its interactions with molecular vibrations, a phenomenon known as the Raman effect.