Sheath flow SERS for chemical profiling in urine

Area of Science:

• Analytical Chemistry
• Biomedical Diagnostics
• Spectroscopy

Background:

• Surface-enhanced Raman scattering (SERS) provides molecular specificity and sensitivity for biomedical diagnostics.
• The complex composition of biological fluids like urine presents challenges for SERS analysis due to analyte masking.
• Limited surface sites and competing absorption can hinder the detection of analytes in complex solutions.

Purpose of the Study:

• To demonstrate the utility and address complications of SERS characterization in urine.
• To present a novel sheath-flow interface for enhanced SERS detection in biological fluids.
• To compare direct SERS detection with capillary zone electrophoresis and sheath-flow SERS for urine analysis.

Main Methods:

• Development and application of a sheath-flow interface for SERS detection.
• Utilizing hydrodynamic focusing to concentrate analyte molecules onto a SERS substrate.
• Comparing direct SERS (DSERS) with capillary zone electrophoresis (CZE) and sheath-flow SERS for benzoylecgonine detection in urine.

Main Results:

• The sheath-flow SERS interface successfully confined analyte molecules for intrinsic SERS signal detection.
• SERS spectra from migration peaks identified benzoylecgonine and other distinct compounds in urine.
• Distinct spectral signatures suggest improved chemical diagnostics capabilities for urine analysis.

Conclusions:

• Sheath-flow SERS detection shows potential for improved chemical diagnostics in complex biological fluids like urine.
• The developed interface addresses challenges associated with analyte masking and limited surface sites.
• Further studies are needed to identify the vast number of compounds in urine and establish clinical utility.