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 MoS₂ basal plane with the Ni-S₃ 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.

单原子催化剂因其出乎意料的催化选择性和活性而被认为是制造电化学生物传感器的潜在催化剂。在这里，我们设计并制造了一种超灵敏的多巴胺（DA）传感器，该传感器基于装饰有单 Ni 位点催化剂（Ni-MoS _{2 ）的花状 MoS 2}。检测限在磷酸盐缓冲液（PBS，pH=7.4）中可达到1 pM，在牛血清（pH=7.4）中可达到1 pM，在人工尿液（pH=6.8）中可达到100 pM。优异的传感性能归因于Ni单原子轴向锚定在MoS ₂基面​​上的Mo原子与Ni-S ₃结构体。实验和密度泛函理论（DFT）结果都证明这种结构特征更有利于DA在Ni原子上的吸附和电子转移。_{MoS 2}基面​​上高比例的Ni活性位点有效地增强了本征电子电导率和对DA的电化学活性。该传感器的成功建立，为拓展单原子催化剂在生物传感器的应用领域提供了新的指导。