Ultra-sensitive Detection of Heavy Metal Using a Fiber Grating-Assisted Plasmonic Electrochemical Sensor

It is necessary that accurate and continuous detection of heavy metal ions around our life. Traditional electrochemical methods have security issues and background interference. To solve these problems, a new method based on surface plasmon resonance (SPR) electrochemical optical fiber sensor system has been put forward. Combined with cyclic voltammetry, SPR can be used for heavy metal ions monitoring simultaneous gold coatings modified on the surface of the optical fiber sensor recording the electrochemical signal, the characteristic is that SPR is highly sensitive and excludes electrochemical background interference. The optical fiber coated with gold film works as a sensor and a working electrode. Optical fiber have a lot of advantages, including flexible operation, compact size and variable shape, opens a new way for high sensitive electrochemical detection. In this paper, heavy metal ion $\mathbf{Pb}^{2+}$ detection is carried out with good electrochemical and optical response.