Unusual Selective Monitoring of N,N-Dimethylformamide in a Two-Dimensional Material Field-Effect Transistor

N,N-Dimethylformamide(DMF) isan essential solvent in industries and pharmaceutics. Its market sizerange was estimated to be 2 billion U.S. dollars in 2022. MonitoringDMF in solution environments in real time is significant because ofits toxicity. However, DMF is not a redox-active molecule; therefore,selective monitoring of DMF in solutions, especially in polar aqueoussolutions, in real time is extremely difficult. In this paper, wepropose a selective DMF sensor using a molybdenum disulfide (MoS2) field-effect transistor (FET). The sensor responds to DMFmolecules but not to similar molecules of formamide, N,N-diethylformamide, and N,N-dimethylacetamide. The plausible atomic mechanism is theoxygen substitution sites on MoS2, on which the DMF moleculeshows an exceptional orientation. The thin structure of MoS2-FET can be incorporated into a microfluidic chamber, whichleads to DMF monitoring in real time by exchanging solutions subsequently.The designed device shows DMF monitoring in NaCl ionic solutions from1 to 200 & mu;L/mL. This work proposes the concept of selectivelymonitoring redox-inactive molecules based on the nonideal atomic affinitysite on the surface of two-dimensional semiconductors.

Automated summary

In this paper, a selective DMF sensor using a molybdenum disulfide (MoS2) field-effect transistor (FET) is proposed. The sensor responds to DMF molecules but not to similar molecules of formamide, N,N-diethylformamide, and N,N-dimethylacetamide. The thin structure of MoS2-FET can be incorporated into a microfluidic chamber, which allows for real-time DMF monitoring by exchanging solutions subsequently. The designed device shows DMF monitoring in NaCl ionic solutions from 1 to 200 μL/mL. This work proposes the concept of selectively monitoring redox-inactive molecules based on the nonideal atomic affinity site on the surface of two-dimensional semiconductors.