NANOTECHNOLOGY: Nanosensors

Nanosensors

Nanotechnology applications in the food industry are contributing to the safety, quality and long shelf life of packed food. Many nano-based health drinks and foods containing nano-food supplements like iron have been manufactured. Nanocomposite, bio-degradable materials are being used for safe packaging and long shelf-life of food products. Composite materials with silicon nanoparticles used for packaging are found to be more airtight, thus preventing food decay (Moore 1999). Nanobiosensors are being used in the packaging material to detect microbiological and biochemical changes in food items, indicating food spoilage. Chip-based micro-arrays, Quantum dots and magnetic nanoparticles have been developed for rapid detection of biological pathogens like E. coli, Salmonella, Staphylococcus etc. in food (Su and Li 2004, Moraru et al. 2003; Yang et al. 2008). Nanobiosensors can also be designed to detect presence of pesticides and possibly genetically modified crops within the food system. Financial services markets

Control of pests and weeds using nano-based materials

Nanotechnology can play significant role in controlled and site targeted delivery of agrochemicals like pesticides and herbicides (Nair et al. 2010). These agrichemicals can be encapsulated in biogedradable, ecofriendly material under specific conditions. Their release can be controlled by structural manipulations, thereby requiring less dosage per application and minimizing runoff of unutilized excess chemicals. The use of nanocapsulated herbicides for the control of parasitic weeds also reduces the ecotoxicity of herbicides (Perez-de-Luque and Rubiales 2009). Surface modified hydrophobic nanosilica has been successfully used to control a range of agricultural insect pests (Barik et al. 2008, Rahman et al. 2009). Photosensitive agrochemicals can be encapsulated in porous hollow silica nanoparticles (PHSN), with a shell thickness of nearly 15 nm and a pore diameter of 4-5 nm, which provide shielding protection from degradation by UV light (Li et al. 2007). Nanomaterial coated fertilizers have been found efficient in slow release of the fertilizers as compared to cemented fertilizers as well as safe for the germination and growth of wheat (Liu et al. 2006, Zhang et al. 2006). Certain agrochemical companies like Syngenta are using nanoemulsions in pesticide formulations. Primo MAXX®, a plant growth regulating product by Syngenta can impart tolerance to turfgrass against different stresses like heat, drought, disease etc. Encapsulated product “gutbuster” releases its contents under alkaline conditions, such as stomach of certain insects and exhibits broad spectrum insecticidal properties against insect pests of soybeans, rice, peanuts and cotton. Another microencapsulated, insecticidal product, Karate ® ZEON breaks open after coming in contact with leaves. (Joseph and Morrison 2006).

Agriculture based nanomaterials for industry use

Electrospinning techniques, where electric (high voltage) force instead of mechanical force is used, have been developed to produce nanofibres from cellulose, derived from scrap materials produced in huge quantity during conventional spinning of cotton (Frazer 2004). These cellulose nanofibres can find applications in filtration, clothing and in agriculture in the form of biodegradable cellulose mats that can absorb pesticides and fertilizers for their controlled release. Carbon nanotube-based composite fibers have been synthesized that are tougher than any natural or synthetic organic fibre. These extraordinary fibres can be woven into electronic textiles (Dalton et al. 2003).

Agriculture on one hand can benefit from nanotechnology and on the other hand, can support growth of nanotechnology. Many plants are known to biosynthesis nanoparticles which can be isolated/ extracted from different plant parts (Kalaugher 2002, Dubey et al. 2009). Many microorganisms including bacteria, fungi, actinomycetes and yeast also possess the ability to synthesize nanoparticles (Mohanpuria et al. 2008; Narayanan and Sakthivel 2010). Thus plants and microorganisms can be used for ‘nanoparticles farming’, wherein plants/microorganisms grown on specific medium/conditions can synthesize nanoparticles which can be harvested, rather than using the current conventional nanoparticles production techniques which are expensive and can have toxic effect on the environment.

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