Optical characterization of bio-analytes in an aqueous environment

Abstract

Urine is a valuable body fluid that can provide significant diagnostic information about a person's health. Since ancient times, urine samples have been analyzed for various diseases, with urine primarily composed of water, non protein nitrogenous compounds such as urea, creatinine, and uric acid, as well as trace amounts of proteins, hormones, enzymes, bacteria, metabolites, and inorganic ions such as chloride, sodium, and potassium. By measuring the varying concentrations of these constituents, a wide range of disorders can be detected at an early stage, including kidney disorders, UTIs, liver diseases, diabetes, and cancers. However, current analytical methods require sample preparation steps, reagents, specialized training, and expensive equipment. Therefore, there is a need for a rapid, reliable, and inexpensive approach that does not require any special preparation. Overcoming the limitations of traditional methods, optical techniques such as fluorescence spectroscopy, IR spectroscopy, UV vis spectroscopy, and Raman spectroscopy have shown great potential for rapid urine analysis. Raman spectroscopy is often preferred over these optical spectroscopic techniques due to its high specificity, sensitivity, and ability to provide detailed molecular information without the need for sample labeling. Compared to other spectroscopic techniques, Raman spectroscopy provides more detailed information on the analyzed samples' molecular structure and chemical bonding.