Brillouin spectroscopy as a new method of screening for increased CSF total protein during bacterial meningitis

Abstract

Bacterial meningitis is a disease of pronounced clinical significance, especially in the developing world. Immediate treatment with antibiotics is essential, and no single test can provide a conclusive diagnosis. It is well established that elevated total protein in cerebrospinal fluid (CSF) is associated with bacterial meningitis. Brillouin spectroscopy is a widely used optical technique for noninvasive determination of the elastic moduli of materials. We found that elevated protein levels in CSF alter the fluid elasticity sufficiently to be measurable by Brillouin spectroscopy, with model healthy and diseased fluids distinguishable to marked significance (P = 0.014), which increases with sample concentration by dialysis. Typical raw output of a 2-stage VIPA Brillouin spectrometer: inelastically scattered Brillouin peaks (arrows) and elastically scattered incident radiation (center cross).

High frequency application of nanosecond pulsed electric fields alters cellular membrane disruption and fluorescent dye uptake

“…Recent research has also shown that mechanical stress may induce some or all of the biophysical effects associated with nanoporation [8][9][10] . The improvement of mechanical spectroscopies 11,12 in recent years should prove useful in the investigation of this mechanism.…”

Surface-enhanced Brillouin scattering in a vicinity of plasmonic gold nanostructures

“…However, weak signals are still difficult to detect in the presence of strong background. This becomes a significant issue when imaging biological tissues [26,27]. Scarcelli and Yun addressed these difficulties by introducing a multi-stage VIPA setup, which provides an additional 25 dB of the background suppression [23].…”

Optimizing signal collection efficiency of the VIPA-based Brillouin spectrometer

“…26 Without an equivalent confocal pinhole (e.g., without an SM¯ber), this broadening e®ect cannot be e±ciently suppressed. 8,27 In the speci¯c measurements shown in Figs. 2(a) and 2(c), the Brillouin line was broadened by 5 pixels (i.e., $400 MHz in Brillouin shift).…”

“…This becomes a signi¯cant issue when imaging turbid biological tissues. 8,22 This problem is further compounded when paired with imperfect optical setups, which are usually polluted with unwanted background noises and signal losses. Scarcelli and Yun addressed these di±culties by introducing a multi-stage VIPA setup, which provides an additional 25 dB of the background suppression.…”

“…[5][6][7][8] Brillouin scattering originates from the inelastic interaction between the incident electromagnetic wave and the acoustic phonons within the material. As a result, the incident optical frequency experiences a shift proportional to the speed of sound in the medium.…”