Abstract: Low concentration of Pb²⁺ can cause multiple damages to the nervous system and blood system of the human body,especially the damage to the nervous system of children is irreversible. In natural environment,Pb²⁺ can also pass into the human body through the biologic chain and affect the health of the human body. Therefore,the detection of Pb²⁺ has attracted wide attention. At present,the traditional methods of detecting Pb²⁺ mainly include Large instrument method,chemical reaction colorimetric method,and electrochemical method;however,there are still disadvantages such as operation complex,cost high,and detection time long. In recent years,using functional nucleic acid to detect Pb²⁺ shows the advantages of simple,rapid,sensitive,and high specialty;therefore,increasing attentions has been paid to Pb²⁺ biosensors based on functional nucleic acid. Firstly,the screening methods and structural properties of Pb²⁺-dependent functional nucleic acids in vitro are introduced. Secondly,the sensors are classified according to the way of signal output in Pb²⁺ functional nucleic acid sensors,including colorimetric biosensor,fluorescent biosensor,electrochemical biosensor,nanomaterial biosensor,and other type of biosensors. Concurrently,the principle,sensitivity,specificity and application fields of various sensors are compared,and then their advantages and disadvantages are evaluated. Finally,the shortcomings are analyzed and the future development direction of Pb²⁺ functional nucleic acid biosensor is prospected,aiming at providing a theoretical basis for developing more portable,more sensitive,and more accurate Pb²⁺ functional nucleic acid biosensors.

Key words: Pb²⁺, functional nucleic acids, nanomaterials, biosensors