Application of terahertz time-domain spectroscopy in intracellular metabolite detection.

Using terahertz time-domain spectroscopy (THz-TDS), we have investigated the THz spectra of astaxanthin and riboflavin and the spectra of two kinds of cell, haenatcoccus plusivalis and bacillus subtilis, which could produce astaxanthin and riboflavin, respectively, during their metabolite process. Riboflavin was found to be much more absorptive to THz radiation and have richer spectral characteristics than astaxanthin. As an intracellular metabolite, riboflavin could be distinguished from the cells by using THz-TDS. The technique has potential applications in high-throughput screening of industrial strains.