An Au25 Nanocluster-Based Electrochemical Biosensor for Profenofos Detection With High Activity and Sensitivity

Exploiting atomic-precision metal nanoclusters as an electrochemical sensor for environmental detection is a significant application in the field of cluster chemistry. However, the development of cluster-based sensors is still in its infancy. Herein, we successfully fabricate a three-layer KBE-CS/Au 25 @MLG/GC electrode (KBE = kidney bean enzyme, CS = chitosan, MLG = multilayer graphene, GC = glassy carbon), in which Au 25 @MLG and CS serve to adsorb and protect the plant esterase of KBE, respectively. The optimized Au 25 -based sensor demonstrates an excellent linear relationship between the mass concentration of profenofos (lgC) and the inhibition rate (Inh %) within the range of 1∼2000 µg/L with a detection limit of 0.137 µg/L. Furthermore, this biosensor presents excellent reproducibility, anti-interference, and stability for the detection of profenofos in real samples. This study paves an avenue to construct a cluster-based detection platform with high performance in electrochemical sensing, facilitating the practical application of metal nanoclusters in pesticide detection. Graphical A three-layer electrochemical sensor is constructed based on an enzyme inhibition mechanism, in which atomically precise Au 25 nanoclusters serve as an electrocatalyst for the conversion of 1-naphthyl acetate to 1-naphthol that can be efficiently recognized in the enzymatic reaction. This novel biosensor exhibits outstanding reproducibility, anti-interference, and stability for the detection of profenofos with a low limit of 0.137 µg/L.