Enhancing Raman signals from bacteria using dielectrophoretic force between conductive lensed fiber and black silicon
Journal
Biosensors and Bioelectronics
Journal Volume
191
Date Issued
2021
Author(s)
Tai Y.-H
Lo S.-C
Montagne K
Tsai P.-C
Liao C.-C
Wang S.-H
Chin I.-S
Xing D
Ho Y.-L
Wei P.-K
Delaunay J.-J.
Abstract
An osmium-coated lensed fiber (OLF) probe combined with a silver-coated black silicon (SBS) substrate was used to generate a dielectrophoretic (DEP) force that traps bacteria and enables Raman signal detection from bacteria. The lensed fiber coated with a 2-nm osmium layer was used as an electrode for the DEP force and also as a lens to excite Raman signals. The black silicon coated with a 150-nm silver layer was used both as the surface-enhanced Raman scattering (SERS) substrate and the counter electrode. The enhanced Raman signal was collected by the same OLF probe and further analyzed with a spectrometer. For Raman measurements, a drop of bacterial suspension was placed between the OLF probe and the SBS substrate. By controlling the frequency of an AC voltage on the OLF probe and SBS substrate, a DEP force at 1 MHz concentrated bacteria on the SBS surface and removed the unbound micro-objects in the solution at 1 kHz. A bacteria concentration of 6 × 104 CFU/mL (colony forming units per mL) could be identified in less than 15 min, using a volume of only 1 μL, by recording the variation of the Raman peak at 740 cm?1. ? 2021 Elsevier B.V.
Subjects
Bacteria detection
Dielectrophoretic force
Lens fiber
Raman enhancement
Dielectric devices
Electrodes
Probes
Silicon
Silver
Substrates
Black silicon
Coated blacks
Dielectrophoretic forces
Fibre probe
Lens-fibre
Lensed fibers
Raman signal
Silicon substrates
Bacteria
silicon derivative
silicon
Article
bacterium
bacterium detection
chemical analysis
coating (procedure)
colony forming unit
concentration (parameter)
controlled study
nonhuman
Raman spectrometry
African American
genetic procedures
human
African Americans
Biosensing Techniques
Humans
Spectrum Analysis, Raman
SDGs
Type
journal article