Carbon Nanotube (CNT)-Based Biosensors

This review focuses on recent advances in the application of carbon nanotubes (CNTs) for the development of sensors and biosensors. The paper discusses various configurations of these devices, including their integration in analytical devices. Carbon nanotube-based sensors have been developed for a broad range of applications including electrochemical sensors for food safety, optical sensors for heavy metal detection, and field-effect devices for virus detection. However, as yet there are only a few examples of carbon nanotube-based sensors that have reached the marketplace. Challenges still hamper the real-world application of carbon nanotube-based sensors, primarily, the integration of carbon nanotube sensing elements into analytical devices and fabrication on an industrial scale.

Heavy Metal Detection based on Coreless Fibers Using the LSPR Technique

In this study, a fiber optic sensing probes based on localized surface Plasmon resonance was presented to detect various Heavy metal zinc concentrations in an aqueous solution. The fiber optic sensing probe consists of a single mode fiber-coreless fiber-single mode fiber structure coated with a 40 nm thickness of gold nanoparticles - polyvinyl pyrrolidone using an immersion method. The results obtained in the experiment showed that the sensor's sensitivity is 1.38 nm/ppm in the range of 0 to 6 ppm concentrations.

A Review of Heavy Metal Toxicity, Effects and Methods for Estimating Heavy Metal Concentration in Water

Heavy metals are metal ions which acts as carcinogens and causes serious health issues as they produce free radicals and these free radicals cause damage to DNA which eventually leads to cancer. They are non-degradable in nature and responsible for contamination of various natural resources in environment mainly water contamination has become a major problem. Many metal ions such as cadmium, lead, arsenic, mercury are considered as toxic metals. The analysis of these metal ions is necessary and to detect these metal ions, several detection methods such as electrochemical biosensors, CNT’s, silver nanoparticles have been developed. In this paper, the toxicity and health effects of several heavy metals and their role in causing of oxidative stress have been summarized. Also, various heavy metal detection methods have been listed.

Nanotechnology for Sustainable Agriculture: An Emerging Perspective

The realm of agriculture has to confront an expansive gamut of challenges including climatic change, stagnant crop yield and the increasing resistance against pesticides. The explicit usage of agrochemicals along with the introduction of high yielding varieties and genetically modified seeds has already directed the agricultural systems towards a state of saturation in production. Therefore, the increasing need of sustainability demands the involvement of advanced nanotechnological approaches for enhancing crop productivity. Enhanced solubility, absorption and target specificity of nannofertilizers prepared using materials like silver, copper, gold and oxides of zinc and iron could address some of nutritional challenges. Nanopesticides such as chitosan loaded with spino sad, silica encapsulating fipronil and sodium alginate enclosing imidacloprid find applications in pest control while fluorescence nanosensor, carbon and graphene nanodots are exploited in herbicide and heavy metal detection. Nanofilteration involving grapheme, cellulose and cyclodextrin for removal of salt, heavy metals and organic pollutants, respectively, could significantly improve quality of hard and waste water making it suitable for irrigation.