Abstract: Provided is an electrode for electrochemical measurement for detecting or quantitatively determining a target substance, the electrode comprising: a complex supported on a surface of the electrode, wherein the complex is a complex comprising a probe for the target substance, a quantum dot which binds to the probe and is doped with nitrogen and sulfur, and a conductive polymer nanowire in which a metal nanoparticle is embedded.

Abstract: Provided is an electrode for electrochemical measurement for detecting or quantitatively determining a target substance, the electrode comprising: a complex supported on a surface of the electrode, wherein the complex is a complex comprising a probe for the target substance, a quantum dot which binds to the probe and is doped with nitrogen and sulfur, and a conductive polymer nanowire in which a metal nanoparticle is embedded.

Abstract: A method of producing riboflavin by culturing riboflavin-producing microbes in a culture medium using a plant oil or an animal oil as a carbon source, forming and accumulating riboflavin therein and collecting riboflavin therefrom, wherein a carrier of a clay mineral having oil-adsorbing property, a chemically treated product thereof or a calcium compound is made present in the culture medium. The riboflavin is produced maintaining a high yield and at an increased production rate at a low cost without requiring cumbersome operations for concentrating and recovering the riboflavin. It is further allowed to recover the riboflavin by effectively utilizing the waste plant oil or the waste animal oil that is to be disposed of.