A colorimetric aptasensor for sulfadimethoxine detection based on peroxidase-like activity of graphene/nickel@palladium hybrids.

See more Nickel products. Nickel (atomic symbol: Ni, atomic number: 28) is a Block D, Group 4, Period 4 element with an atomic weight of 58.6934. The number of electrons in each of nickel's shells is [2, 8, 16, 2] and its electron configuration is [Ar]3d⁸ 4s². Nickel was first discovered by Alex Constedt in 1751. The nickel atom has a radius of 124 pm and a Van der Waals radius of 184 pm. In its elemental form, nickel has a lustrous metallic silver appearance. Nickel is a hard and ductile transition metal that is considered corrosion-resistant because of its slow rate of oxidation. It is one of four elements that are ferromagnetic and is used in the production of various type of magnets for commercial use. Nickel is sometimes found free in nature but is more commonly found in ores. The bulk of mined nickel comes from laterite and magmatic sulfide ores. The name originates from the German word kupfernickel, which means "false copper" from the illusory copper color of the ore.

See more Palladium products. Palladium (atomic symbol: Pd, atomic number: 46) is a Block D, Group 10, Period 5 element with an atomic weight of 106.42. The number of electrons in each of palladium's shells is 2, 8, 18, 18 and its electron configuration is [Kr] 4d¹⁰. The palladium atom has a radius of 137 pm and a Van der Waals radius of 202 pm. In its elemental form, palladium has a silvery white appearance. Palladium is a member of the platinum group of metals (along with platinum, rhodium, ruthenium, iridium and osmium). Palladium has the lowest melting point and is the least dense of the group. Palladium can be found as a free metal and alloyed with other platinum-group metals. Nickel-copper deposits are the main commercial source of palladium. Palladium was discovered and first isolated by William Hyde Wollaston in 1803. Its name is derived from the asteroid Pallas.

See more Carbon products. Carbon (atomic symbol: C, atomic number: 6) is a Block P, Group 14, Period 2 element. The number of electrons in each of Carbon's shells is 2, 4 and its electron configuration is [He]2s² 2p². In its elemental form, carbon can take various physical forms (known as allotropes) based on the type of bonds between carbon atoms; the most well known allotropes are diamond, graphite, amorphous carbon, glassy carbon, and nanostructured forms such as carbon nanotubes, fullerenes, and nanofibers . Carbon is at the same time one of the softest (as graphite) and hardest (as diamond) materials found in nature. It is the 15th most abundant element in the Earth's crust, and the fourth most abundant element (by mass) in the universe after hydrogen, helium, and oxygen. Carbon was discovered by the Egyptians and Sumerians circa 3750 BC. It was first recognized as an element by Antoine Lavoisier in 1789.