Electrochemical aptasensor based on PEI-Fe-MOF/Au@Ag NPs nanocomposites for streptomycin detection in dairy products

Abstract

Streptomycin (STR) residues in dairy products could cause serious health risks for human or affect the quality of the dairy products fermented by lactic acid bacteria, thereby resulting in economic losses. Thus, STR detection methods need to be developed quickly, simply, and sensitively. In this study, polyethyleneimine (PEI)-functionalized NH2-MIL-101(Fe) (PEI-Fe-MOF) was characterized and found to exhibit an enhanced electrochemical characteristics, when compared to Fe-MOFs. Au@Ag core-shell NPs could further amplify its electrochemical signal. Based on the PEI-Fe-MOF/Au@Ag NPs nanocomposites, we have developed a novel electrochemical aptasensor to detect STR rapidly. When detected under optimal conditions, a wide linear range between 0.1 and 200 nM was observed for the aptasensor with a detection limit of 0.033 nM. Furthermore, the developed aptasensor has been satisfactorily applied for the rapid STR detection in dairy products with recoveries ranging from 98.2% to 110.1%. Therefore, our method can be considered a new effective method for the rapid detection of STR in dairy products.