Non-invasive disease diagnosis using surface-enhanced Raman spectroscopy of urine and saliva

Due to the high sensitivity, specificity, efficiency and cost-effectiveness, surface-enhanced Raman spectroscopy (SERS) has been extensively used for the detection and evaluation of biological substances in body fluids, such as blood, tissues and cells. However, collecting these bodily species is not very convenient because patients have to suffer from skin irritation pain and contacted injection risks. Urine and saliva, which carry abundant metabolic information, can also reflect the health conditions about the human body and seems to be more practicable and convenient for truly non-invasive disease diagnosis. In particular, a number of cancers, diseases and illicit drugs have been successfully recognized and analyzed based on the SERS spectra of urine and saliva, enabling a screening of certain diseases and a tracing of disease development. In this review, we will introduce the state-of-the-art regarding the clinical applications of SERS analysis on urine and saliva, and briefly discuss the future development of SERS based non-invasive disease diagnosis.