Dielectric response of graphene and MoS2 nanopores in the detection of single amino acids

Recent advances in two-dimensional material nanopores have promoted significant progress in biosensing technology with single-molecule precision. The potential of detecting single amino acids using graphene and MoS 2 nanopores is investigated here, using density functional theory combined with dielectric response calculations and quantum transport simulations. The electronic transport and the optical response of the nanopores are calculated, and their modifications in the presence of the selected amino acids are assessed. While the current-voltage characteristics of the nanopores show very modest modifications, the optical absorption spectra reveal quite evident modulations when an amino acid is present in the nanopore. The dielectric response of the MoS 2 nanopores exhibits a broader spectrum of photon energy compared to the graphene ones. Specifically, the calculated optical sensitivity in distinguishing among amino acids in MoS 2 nanopores reaches up to 90% compared to roughly 60% in graphene nanopores. For the latter, the calculated sensitivity in the transport mode, that is using the electronic current as a detection observable, is approximately 10 times lower. In the end, all observations are discussed in view of a potential broadband optical detection for protein detection platforms and biosensors.