A Highly Selective and Interference-Resistive Opto-Mechatronic Sensor for Fast Detection of Nickel Ions

In this research, we developed an innovative, miniature, low-cost, and fast-response nickel ion photoelectric sensor system using the principle of light absorption characteristics described by Beer–Lambert’s law. We used the proposed ideas to analyze the absorption spectrum of nickel ions in aqueous solutions and selected a unique UV absorption band for these ions, and successfully fabricated an initial photoelectric sensor system. A quantitative study through the relationship between the concentration of nickel ions in the aqueous solution and the degree of light absorption was conducted. When other metal ions (such as Cd, Pb, Fe and Cl) co-exist, the nickel ion photoelectric sensor shows excellent selectivity and has sufficient linearity and good repeatability. The sensitivity of the originally designed photoelectric sensing system for Ni ions is 1.58 UVA intensity (A.U.)/ppm with excellent ion-selective characteristics and interference-resistant ability in terms of its complexity and fabrication cost.