Nanomaterials for Environmental Burden Reduction, Waste Treatment and Non-Point Source Pollution Control - Nanotechnologies for Water Environment Applications - page 454

breakthrough for pathogen and contaminant detection and animal diagnostics.
Production and processing of agriculture and food products can be made more secure by
the development and implementation of nanosensors for pathogen and contaminant
detection. Nanostructured catalysts can increase the efficiency of pesticides and
herbicides, allowing lower doses to be used. Protection of the environment through the
reduction and conversion of agricultural materials into valuable products can be made
easier by nanotechnologies.
In agriculture, harmful substances (pesticides) can be converted into harmless
compounds by the photocatalysis process, such as decomposition of toxic pesticides.
Nanomaterials are widely applied in the photocatalysis process. Nano-sized metal oxides
such as TiO 2 (Bhatkhande et al., 2001), ZnO (Li and Haneda, 2003), and ZnS (Torres-
Martinez et al., 1999) have been used for the photocatalysis.
New nanostructural catalysts to convert vegetable oils and other plant wastes
(e.g., core stover) into bio-fuels and biodegradable industrial solvents have been studied.
Protection of the environment through management of local and environmental
emissions is another exciting area of agriculture that could benefit from nanotechnology.
Development of nano-phase soil additives (fertilizers, pesticides, and soil conditioners)
is helpful to reduce the agricultural wastes, control global CO 2 levels and improve food
quality through nanoscale processes that enhance nutritional compositions of foods.
In the food industry, food proteins are often 1-10 nm in size, and most
polysaccharides (carbohydrates) and lipids (fats) are less than nanometers in size.
Various additives or ingredients with nano-sizes are approved for use in food contact
materials. The inclusion of nanoparticles in food packages can be used to produce novel
types of packaging materials and containers. For example, TiO 2 nanoparticles are
transparent but retain their UV absorption characteristics. This may apply to transparent
wraps, films or plastic containers where absorption of UV radiation needs to be avoided.
Nanofilms can prevent unwanted materials from getting into food. Green sensors
equipped on a meat package may detect the presence of more than a threshold level of
harmful bacteria (Busch, 2008). An electronic nose is a device which uses a pattern of
response across an array of gas sensors to identify different types of odors. Recently,
electronic noses composed of nanoparticles, such as ZnO nanowires have been
developed (Sugunan et al., 2004; Hossain et al., 2005). Bacteria are the most primitive
life forms almost everywhere. Some are useful, but others are causing diseases. Organic
dyes are the most commonly used biolabels to detect the bacteria. Recently, quantum
dots (QDs, 1-100 nm) with bio-recognition molecules have been used as fluorescent
labeling of detecting bacteria. The QDs have prominent advantages over organic dyes as
the QDs are more efficient in luminescence and show excellent photostability (Vacassy
et al., 1998), their emission spectra are narrow and tunable. Warad et al. (2004) reported
ZnS:Mn 2+ nanoparticles capped with chitosan bio-labeled bacteria bacillus. Su and Li