Study on characteristic peaks of antibiotics and amino acids based on terahertz time-domain spectroscopy

Changes in antibiotic and amino acid concentrations are closely related to human beings, the natural environment and animal and plant life and health. Real-time and label-free detection using terahertz time-domain spectroscopy (THz-TDS) is of great significance for disease prevention and treatment and drug residue detection. However, water has a strong absorption of THz waves that cannot be ignored, which hinders the detection of water-containing samples. In this paper, the characteristic absorption peaks and molecular vibration modes of penicillin sodium and L-hydroxyproline were studied based on THz-TDS and density functional theory (DFT) using IPCA with high radiation properties. The absorption peaks of samples in different states are different, and the formation of new hydrogen bonds will cause the absorption peak to disappear, or a blue shift or a red shift occurs. The intramolecular interaction forces were then characterized based on IRI analysis. Based on this method, solutions with a minimum concentration of 842 μM can be qualitatively tested.