Abstract

Lab on a Chip Devices With Spectroscopic Readout For Biomedical Applications

Ute Neugebauer, Group Leader, Leibniz Institute of Photonic Technology, Jena

Early disease recognition, targeted treatment and monitoring treatment success are visions associated with medical photonics. Raman spectroscopy plays a key role in turning this ambitious vision into reality because it allows for labelfree monitoring of life processes. The application of spectroscopic methods as point-of-care tests requires chip-based sampling methods offering the opportunity to handle small sample volumes and to apply sample preparation steps. Here, we will present chip-based bacterial isolation strategies for a fast Raman spectroscopic identification of pathogens and the determination of their antibiotic resistances, which is crucial for patient’s survival. Before Raman spectroscopy can be used to characterize pathogens, they have to be isolated from the sample matrix, i.e., body fluids like blood or urine or infected tissue samples, which poses a great challenge. We will present chip-based bacterial isolation strategies directly from real world samples using dielectrophoretic and centrifugal forces for a fast Raman spectroscopic identification of pathogens. Spectroscopic characterization of bacteria – drug interaction provides insights into their antibiotic susceptibility. Moreover, we present lab-on-a-chip (LOC) surface enhanced Raman spectroscopy (SERS) which is interesting for detecting low-concentration analytes in bodyfluids and could be applied for therapeutic drug monitoring. The combination of SERS with a droplet-based microfluidic platform guarantees high sample throughput and reproducible SERS conditions. Finally, we introduce novel approaches for Raman spectroscopic analysis of blood cells in microfluidic systems, such as the use of microhole chips for the analysis of immune cells and combinations with optical traps to identify and to sort circulating tumor cells.