A sensitive aptasensor mediated by gold nanoparticles/metal organic framework lattice for detection of Pb2+ ion in marine products.

Herein, an enzyme-free fluorescent aptasensor was introduced for the ultrasensitive quantification of lead (Pb2+) ion as a hazardous pollutant of the environment and foodstuffs. A nanocomposite of zeolitic imidazolate frameworks-8 and gold nanoparticles (ZIF-8@AuNPs) was utilized as an efficient quencher of the fluorescence intensity of carboxyfluorescein (FAM) signal reporter. The establishment of a hybrid structure between attached aptamer on ZIF-8@AuNPs nanocomposite, and its FAM-tagged complementary (CP) strand decreased the fluorescence response. The preferential binding between the aptamer and Pb2+ released CP strands, which retrieved the fluorescence signal. The aptasensor could assess Pb2+ in the linear concentration range of 1 pM-1 nM with a detection limit (LOD) of 0.24 pM. Besides, it could quantify Pb2+ in various samples, including fish, shrimp, tap water, milk, and serum samples. The developed aptasensor with the superiorities of easiness, cost-effectiveness, easy-to-operate, and rapidness is promising for controlling marine foodstuff safety. [Display omitted] • An ultrasensitive fluorescent aptasensor was developed for monitoring of Pb2+ ion. • ZIF-8@AuNPs nanocomposite was utilized as a fluorescence nanoquencher skeleton. • Pb2+ was determined with a detection limit of 0.24 pM. • Pb2+ was detected in fish, shrimp, tap water, milk, and human serum samples. [ABSTRACT FROM AUTHOR]