Wavelength Tech Forum: Raman

Wavelength Tech Forum: Raman

June 4, 2010

Raman research continues to grow at a rapid pace, with new applications being discovered and old applications being finetuned and perfected every day. Joining us for this discussion are Harald Fisher of Witec; Scot Elis of Thermo Fisher Scientific; and Jorge Macho of Ocean Optics.

Raman research continues to grow at a rapid pace, with new applications being discovered and old applications being finetuned and perfected every day. Joining us for this discussion are Harald Fisher of Witec; Scot Elis of Thermo Fisher Scientific; and Jorge Macho of Ocean Optics.

What has been the single most important development in Raman research over the past year?

Fisher: From our point of view, the development of confocal Raman imaging was a great development for the Raman community improving the general throughput in a way that high-resolution 3D chemical imaging became possible at the highest spectral sensitivity. Also, the possibility of combining Raman with other surface analysis techniques such as AFM was a great step.

Elis: Raman is developing in many directions with high importance. SERS is developing great potential as a diagnostic and life science tool. Materials science fields, such as nanotechnology and, in particular, carbon nanomaterials, are accelerating the use of Raman as an applied tool not just a research technique. Technologies improving portability, performance, and ease-of-use are all making more applications possible, but the excitement in these new application areas is starting to drive where the technology goes, rather than the other way around.

Macho: I think the focus on new SERS materials and the push to commercialize them so that the market can have more options are important developments.

What obstacles does Raman face in the future and how can they be overcome?

Fisher: With Raman microscopy, one must account for low light intensities, so further improvement of the overall sensitivity is one of the most important challenges to face in the future.

Elis: Until recently Raman has remained an expert technique, full of spectroscopic challenges, unique sample issues, and finicky instrumentation that made it challenging to get good data on a consistent basis. True under-the-hood intelligence and optical stability have really only started to appear in Raman designs in the last couple of years, enabling new users who are not Raman experts to depend on the technique. The same was required and has been happening to really create a handheld market. There is no question that Raman performance and technology will keep evolving, but the biggest lever on Raman growth will be to continue to make it easier, more reliable, more trustworthy.

Macho: The same obstacles that are inherent to the technique. Improvements must come in the areas of sensitivity and fluorescence abatement. Constant development of new detectors and higher power UV diode lasers will help with these issues.

How close is portable Raman instrumentation to matching its benchtop counterpart in speed, sensitivity, and overall performance?

Fisher: Due to the different technical design of a benchtop Raman microscope, a comparison with a portable Raman spectrometer is and will be quite difficult. However, with further improvements in detector technology one might assume that portable spectrometers will eventually catch up with their laboratory counterparts.

Elis: That’s a bit like asking if a video surveillance security system has brilliant colors, 1080i resolution, and surround sound. But the two do entirely different tasks in completely different settings and situations. Portable Raman available today is easily good enough by those traditional lab instrument criteria to solve valuable problems outside the laboratory. Laboratory Raman is evolving on a technological vector pushing traditional performance limits for materials research and characterization.

Macho: The answer to this question is completely directed to the application. Materials identification today can be done almost identically with both options. On the other hand, portable Raman or LRRS in general can not cope with molecular structural analysis in its current state.

What application areas will be the most critical to the future growth of Raman technology? (i.e., pharma, homeland defense, etc.)

Fisher: We see that, especially in biomedical research, there is huge potential for Raman instrumentation.

Elis: The materials science and life science areas mentioned before will drive Raman growth. Handheld and portable analysis offers huge potential outside of the laboratory. For example, the pharmaceutical industry is increasingly turning to Raman as a path toward 100% inspection of raw materials and homeland defense continues to find new benefits of molecular identification in the field. Advances in portability, laser technologies, and ease-of-use will drive Raman to greater acceptance as a QA/QC tools as well.

Macho: Homeland Security is driving the growth in this market and will continue this trend thanks to the new SERS materials that have been developed for biochemical detection purposes. The pharmaceutical and food industries will benefit from these advances and will follow the development trend just as they have done in the last years.

Where will Raman technology and instrumentation be in 20 years? What capabilities will the Raman instrument of the future possess?

Fisher: Although there will still be further improvements in sensitivity along with new developments in detector technology, a future key feature will be a user-friendly data evaluation for automated post-processing of the Raman imaging data.

Macho: Twenty years is a long time and by then the technique will be mature and commoditized. Due to the cost reduction trend and generalization of the instrumentation as material identification systems they can become as common as a pH meter or even used at commercial points, for example, to check for produce viability at a supermarket or to verify a prescription in a drug store.

What do you think?

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If you are interested in participating in any upcoming Technology Forums please contact Editor-in-Chief David Walsh or Associate Editor Meg Evans for more information. Next month’s forum will be a discussion about X-ray.