Detection of mercury ion based on quantum dots using miniaturised optical fibre sensor

Abstract

Mercury ion (Hg2+) is one of the common pollutants which exists in the natural environment far and wide. The detection of Hg2+ usually requires large laboratory equipment, which limits their field applications. Here, a miniaturised optical fibre sensor based on quantum dots (QDs) for detection of Hg2+ is developed. The sensor is based on the principle of fluorescence quenching caused by Hg2+ and evanescent wave sensing. It is an all-fibre sensor which composed of an optical fibre probe module, an optical module and a signal acquisition module. Through miniaturisation design of optical system and the structure of the sensor, the sensor is reduced to the volume of 120 × 120 × 100 mm. The experimental results show that in the miniaturised sensor both has high sensitivity and fast response speed. Meanwhile, the ion anti-interference experiment shows that the sensor has good selectivity for Hg2+ detection. In general, the proposed sensor has significant potential in the field of biochemistry, environmental monitoring, and food safety.