ABSTRACT
One of the most important environmental concerns worldwide is pollution of terrestrial and hydric resources with heavy metals. Based on toxicity of substance and potential exposure to contaminated air, water, and soil, arsenic, lead, mercury, and cadmium possess the greatest potential threat to human health, being ranked in the top 10, as the first, second, third, and seventh elements, respectively, while chromium holds the seventeenth position in Priority List of Hazardous Substances. Frequently, the highly sensitive quantification of these toxic substances in complex matrices is carried out by some spectroscopic techniques. Carbon nanotubes (CNTs) are at the forefront as the most advantageous candidates for improving the electro-sensing performance and allowing the development of completely new nanoscale sensors and biosensors. Pristine CNTs are insoluble in aqueous solutions, polymer resins, and most solvents due to their hydrophobic surfaces. Arsenic affects about 140–200 million people in 70 different countries on all inhabited continents, mainly due to the contamination of drinking and ground waters.
