Surface modification of MoS2 nanosheets by single Ni atom for ultrasensitive dopamine detection

Single atom catalysts have been recognized as potential catalysts to fabricate electrochemical biosensors, due to their unexpected catalytic selectivity and activity. Here, we designed and fabricated an ultrasensitive dopamine (DA) sensor based on the flower-like MoS2 embellished with single Ni site catalyst (Ni-MoS2). The limit of detection could achieve 1 pM in phosphate buffer solution (PBS, pH=7.4), 1 pM in bovine serum (pH=7.4), and 100 pM in artificial urine (pH=6.8). The excellent sensing performance was attributed to the Ni single atom axial anchoring on the Mo atom in the MoS (2) basal plane with the Ni-S-3 structure. Both the experiment and density functional theory (DFT) results certify that this structural feature is more favorable for the adsorption and electron transfer of DA on Ni atoms. The high proportion of Ni active sites on MoS2 basal plane effectively enhanced the intrinsic electronic conductivity and electrochemical activity toward DA. The successful establishment of this sensor gives a new guide to expand the field of single atom catalyst in the application of biosensors.

Automated summary

Single atom catalysts have great potential in the fabrication of electrochemical biosensors due to their unexpected catalytic selectivity and activity. In this study, a highly sensitive dopamine sensor was designed and fabricated using flower-like MoS2 decorated with a single Ni site catalyst. The sensor exhibited excellent performance with low detection limits in various solutions. The exceptional sensing capabilities can be attributed to the axial anchoring of Ni single atoms on the MoS2 basal plane.