Selective and efficient electrochemical biosensing of ultrathin molybdenum disulfide sheets

Atomically thin molybdenum disulfide (MoS₂) sheets were synthesized and isolated via solvent-assisted chemical exfoliation. The charge-dependent electrochemical activities of these MoS₂ sheets were studied using positively charged hexamine ruthenium (III) chloride and negatively charged ferricyanide/ferrocyanide redox probes. Ultrathin MoS₂ sheet-based electrodes were employed for the electrochemical detection of an important neurotransmitter, namely dopamine (DA), in the presence of ascorbic acid (AA). MoS₂ electrodes were identified as being capable of distinguishing the coexistence of the DA and the AA with an excellent stability. Moreover, the enzymatic detection of the glucose was studied by immobilizing glucose oxidase on the MoS₂. This study opens enzymatic and non-enzymatic electrochemical biosensing applications of atomic MoS₂ sheets, which will supplement their established electronic applications.