Conclusions - Waterborne Pathogens: Detection Methods and Applications - page 371

Chapter 9 discussed how nanotechnology can be applied to enhance the
sample processing and detection schemes presented in previous chapters,
as well as enabling new approaches. Nanotechnology is predicted to have
a huge impact on pathogen diagnostics in a wide variety of fields over the
next decade and has been the subject of much recent work, though the
majority of the studies are not specifically related to waterborne pathogen
detection. Bacteria, and particularly E. coli have been well studied with fewer
reports of detection of viruses and protozoa. Gold nanoparticles enable new
colorimetric detection schemes, which are especially advantageous for cheap
diagnostics, e.g. for developing country applications. Other new methods
of sample processing and detection have also been invented, e.g. depletion
flocculation or the magnetic relaxation switch approach. As yet, however, it
appears that nanotechnology has not yet lived up to its potential and while
many studies report signal enhancements using nanotechnology, this is often
just one or two orders of magnitude. Given the recent growth in the research
area though, further developments and improvements can be expected.
Chapter 10 has considered the potential of miniaturization and the role
that lab-on-a-chip devices could play in waterborne pathogen monitoring.
For all the detection methods discussed above, there are microfluidic sys-
tems for performing these tests, though not always for waterborne pathogen
applications. Performing fluorescent detection on-chip offers many advan-
tages including: the reduced sample volume resulting in a lower background
noise signal and, therefore, improved sensitivity and signal to noise ratio; the
small sample volume and control of flow enhancing binding kinetics and
increasing sensitivity; and the reduced consumption of reagents. Perform-
ing molecular methods on-chip is an excellent way to exploit many of the
advantages of lab-on-a-chip miniaturization and this is likely to be one of
the main future directions for microfluidic waterborne pathogen detection.
As yet, however, the potential of microfluidics is not widely exploited in
the waterborne pathogen monitoring arena, and indeed more examples
of foodborne pathogens can be found in the literature. Given that many
of these pathogens are similar, indicates that there is scope for wider use
of microfluidics. One potential challenge is the sample processing of large
volumes of complex environmental water, due to potential problems with
device clogging as well as obtaining sufficient throughput. However, despite
this concern, examples have been found of microfluidic approaches to
waterborne sample processing.
Chapter 11 explored the application of emerging technologies for
waterborne pathogen detection from a market perspective. The water