A portable fluorescent aptamer sensor for rapid quantitative detection of Hg2+

Abstract

Mercury (II) ions (Hg2+) are heavy metals can cause human poisoning, and severe cases can lead to death. Therefore, establishing a rapid quantitative detection method for Hg2+ is important for protecting human health. A portable hydrogel-based fluorescent aptasensor for the rapid and quantitative detection of Hg2+. In this study, a type of RCA/G-quadruplex product was designed during the rolling circle amplification (RCA) process. By combining it with the Thioflavin T (ThT) fluorescent dye, a highly efficient RCA-ThT fluorescent probe was obtained, which can sensitively and efficiently recognise Hg2+. Furthermore, the RCA-ThT fluorescent probe was physically combined with a hydrogel to construct a novel hydrogel-based fluorescent sensor has been constructed. The hydrogel combined with the RCA-ThT fluorescent probe is dropped onto the lid of a centrifuge tube. The solution will be detect containing Hg2+ is added to the same centrifuge tube. The centrifuge tube is inverted so that the solution will be detect comes into contact with the sensor. This enables the completion of portable rapid detection and fully complies with the basic requirements of Point-Of-Care Testing (POCT). Additionally, the RGB values are obtained through photo capture, and colorimetric analysis is used to determine the definite content of Hg2+ by a WeChat App. The portable hydrogel-based fluorescent aptamer sensor had a detection limit of 0.044 μmol/L for Hg2+ and a detection range of 1-100 μmol/L. The sensor exhibits good stability and immediate detection capabilities, showing promising application prospects in food safety monitoring.