Quantitative detection of solid sialic acid using terahertz time-domain spectroscopy

Sialic acid is one of the key constituents in tumor-specific glycans and an important biomarker for a diversity of cancer types. Its content change in the blood serum can be used for early diagnosis of cancer, grading of cancer, and evaluation of therapeutic effect and prognosis. In this paper, we studied and analyzed the terahertz (THz) response of solid sialic acid samples with five concentrations. Based on the characteristics of the peak value among absorption coefficient spectrum, linear fitting is performed to achieve the quantitative detection of sialic acid.