Shock wave-exposed α-D-glucose: structural, optical and antibacterial studies towards understanding biological...

In the present study, the effects of acoustic shock waves on α-D-glucose were investigated. The shock waves were generated using a semi-automated Reddy tube with a Mach number of 1.5, a pressure of 0.59 MPa and a transient temperature of approximately 520 K. The response of the shock-treated samples provided valuable insights, demonstrating that α-D-glucose can serve as an excellent model system for both fundamental and applied research. Powder X-ray diffraction (PXRD) analysis revealed that the control sample of α-D-glucose exhibited an orthorhombic crystal structure with the space group P2₁2₁2₁. This structure remained stable even after exposure to up to 500 shock pulses. However, a significant enhancement was observed in the diffraction peak corresponding to the (211) crystalline plane, particularly after 400 and 500 shock pulses, indicating an increase in crystallinity. Similarly, Raman spectroscopy showed noticeable intensity fluctuations in the spectral intensity for samples exposed to 400 and 500 shock pulses, suggesting modifications in the vibrational behaviour of the molecular structure. UV- DRS results revealed that the optical band gap decreased from 4.45 eV for the control sample to 4.25 eV after 500 shock pulses, indicating tuneability of the optical properties. FE-SEM images further revealed significant changes in particle size in the shock-treated samples. In addition, the antibacterial activity of both control and shock-treated samples was evaluated against Bacillus subtilis and Escherichia coli. Moreover, the results demonstrate that the solid-state properties of α-D-glucose can be significantly modified under acoustic shock-treatment conditions. Such harsh environments are believed to have played an important role in the chemical evolution of organic molecules before the emergence of life on Earth.