Biomedical Engineering Reference
In-Depth Information
of spoilage organisms. Time is something that is scarce in the fresh pro-
duce business. Fast, cheap, and easy-to-use diagnostic tests that can quan-
tify certain spoilage organisms in a sample of the fresh product would very
much help the fresh markets. These tests can be developed with micro- and
nanotechnologies. Depending on the organisms to be determined, different
types of diagnostic kits can be developed. Needless to say, these applications
greatly benefit from developments in the medical diagnostic field.
In the previous section, the aim was to quantify the spoilage organisms.
However, there are also organisms, such as campylobacter, in the meat indus-
try that are not allowed at all. In this case, a yes/no test is called for. Although
this seems an easier task than to quantify organisms, there are some specific
difficulties surrounding these determinations. One of the more important
problems is related to the regulatory framework that is designed to assure
food safety in these products. Regulation prescribes that not one organism
is allowed in a 25 g sample of the product. A 25 g sample obviously does not
agree with tests based on micro- and nanotechnology principles since they
work with very small amounts of material. Sample pretreatment and amplifi-
cation of the substance to be detected need to be done to increase the sensitiv-
ity and to make the translation from milligrams or micrograms to 25 g. An
alternative could be that nanotechnology tests are used as a prescreening of
the official tests and allow internal decisions within the fresh food produc-
tion company. Another alternative would be that regulations are changed to
accommodate new test strategies. However, this will only be initiated after
the effectiveness of these tests is proven, and this is a lengthy procedure.
5.5 Applications in Water
Water is abundant on Earth. However, the problem is that most of it contains
unwanted substances. Only a very small part of all the water on the planet
is sweet, and even that water can easily be polluted owing to the unwanted
effects of different economic activities such as agricultural and chemical pro-
duction. Unfortunately, virtually all land-dwelling biological organisms and
many of the species that live in water rely on the availability of sweet water
of sufficient quality. Providing enough clean, sweet water to all humans, ani-
mals, and plants is one of the major problems mankind faces in the coming
decades. There are two routes in which nanotechnology can help solve this
problem: purification and filtration.
5.5.1 Filtration
To get rid of larger components in water by filtration is a simple method.
With microtechnology, very accurate and reproducible holes can be created
