Optical Waveguide-Based Biosensors Using Noble Metal Nanoparticles - From Bioimaging to Biosensors: Noble Metal Nanoparticles in Biodetection - page 98

5.6 Conclusions and Outlook

Label-free biosensing systems enable lexibility to the process of
assay design with potentially fewer artifacts. Scientists in both
academia and industry are using biosensors in areas that encompass
almost all areas of the chemical and biological sciences, but the
technology remains some way from being accepted as mainstream.
This chapter has described studies related both to the fundamentals
and applications of OW-PPR biosensors. The results demonstrate
that the OW sensing technology enhance the sensitivity of the
PPR biosensing technique. Furthermore, OW-PPR measurement
is based on extinction spectroscopy and, hence, the normalization
by I S / I R or ( I R − I S )/ I R = Δ I S / I R , the relative change of transmission
response, alleviates the demand on precise optical alignment. In
other words, the OW-PPR sensor response presented as I S / I R or Δ I S /
I R provides a mean of normalization to ensure that some variation of
I R is acceptable. Despite these advantages, many practical challenges
remain before OW-PPR biosensors can reach their full potential
as analytical tools for chemical quantiication, characterization of
binding afinities and kinetics, and detection of conformational
changes. As technology is developed to improve the instrumentation
aspects such as instrumental resolution, instrument stability, easy
to operate, user-friendly software, ease of data interpretation,
portability, and inexpensive, as mass production techniques mature
and nanoparticles become more uniform and stable, and as more
diverse and complementary techniques such as mass spectrometry,
surface-enhanced Raman scattering, electrochemical techniques,
and microluidics are integrated, future commercialization of PPR
biosensors is foreseeable.

Acknowledgment

This work was supported by the Natural Science Council (Taiwan),
National Chung Cheng University, and Buddhist Dalin Tzu Chi General
Hospital.

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