Microfluidic Raman spectroscopy for bio-chemical sensing and analysis

P. C. Ashok, and K. Dholakia, W. Fritzsche, and J. Popp

Springer Series on Chemical Sensors and Biosensors: Optical Nano- and Microsystems for Bioanalytics, 247-268 (2012)

doi: 10.1007/978-3-642-25498-7_9 

The detection and analysis of bio-chemical analytes are important in the fields of personal healthcare, drug development, and environmental science, among others. The field of microfluidics aims to realize portable devices which can perform fast and sensitive bioanalyte detection with minimal sample preparation. Raman spectroscopy is a powerful tool for analyte detection owing to its high specificity and its ability for multi-component detection in an analyte. Combining microfluidics with Raman spectroscopy would help achieve miniaturized analytical devices that may provide rich information about a given analyte. However, the low cross-section of Raman process demands special geometries to achieve such a convergence. The majority of the previous embodiments were restricted to free-space geometry, limiting portability. However, in recent studies, fiber-based Raman detection system incorporated in microfluidics offers the opportunity to develop portable optofluidic bioanalyte detection devices. Here, we review various approaches used for using Raman spectroscopy in microfluidics for analyte detection, and various analytical approaches that could be used to enhance the detection sensitivity of Raman spectroscopy-based detection. This is followed by a detailed discussion about the fiber-based optofluidic Raman detection systems.