Traditional heavy metal detection methods rely on large instruments, requiring complex and cumbersome pre-treatment processes, high detection costs, and long detection cycles. Meanwhile, traditional detection methods face issues of low sensitivity and low level of intelligence. Therefore, it is urgent to establish high sensitivity and intelligent heavy metal detection methods to compensate for the shortcomings of traditional methods. Biosensors are fast detection methods with advantages such as fast response, low cost, high sensitivity, and easy portability. They can overcome the limitations of traditional detection methods and have great application prospects in simple, fast, and highly sensitive detection of heavy metals.

Liu Chengshuai, a researcher in the State Key Laboratory of Environmental Geochemistry of the Institute of Geochemistry, Chinese Academy of Sciences, and Chen Junhua, a researcher in the Institute of Ecological Environment and Soil Research, Guangdong Academy of Sciences, have established a heavy metal biosensor with functional nucleic acids as molecular recognition elements, realized ultra sensitive, intelligent and rapid detection of heavy metals, and constructed a new method for detecting soil available heavy metals.

The team has established a DNA network nanostructure biosensor, achieving ultra sensitive detection of heavy metals in soil. Researchers have innovatively used double stem ring DNA probes as self-assembled elements. When there are heavy metals to be detected in the reaction system (using uranium ions as an example), the released nucleic acid fragments can activate DNA assembly. After multiple cycles of nucleic acid hybridization and chain displacement reactions, a fluorescent biosensor with a DNA network nanostructure is formed. The fluorescence biosensor has a linear detection range of 10 pM to 1 mM for uranium ions, with a detection limit of 2 pM, and can achieve ultra sensitive detection of trace uranium pollution in soil samples. This fluorescent biosensor has simple operation, fast response, and efficient signal amplification efficiency, providing a new method for ultra sensitive detection of heavy metals in soil.