▎ 摘　　要

Taking advantage of a nanopore-based DNA sequencing concept, a variety of recognition approaches have been intensively explored. We have recently presented a potential mechanism for DNA sequencing based on interband pi plasmons of graphene nanopores. In this paper, a realistic ab initio analysis of the proposed method based on it and also pi+sigma plasmons is investigated making use of graphene quantum dots (GQDs) with a nanopore. The plasmonic properties are studied by post processing the density functional theory (DFT) calculations. The first principle study provides an unprecedented fully theoretical description of the proposed structure. The critical features such as passivating atoms, structure relaxation, DNA-graphene interactions, and nucleobase rotations are considered, which result in a more accurate and realistic description of the presented method. Our calculations show a 0.04 to 0.28 eV shift to the energy of the plasmonic modes related to each inserted nucleobase in the nanopore of GQD, which demonstrates the promising potential of the method. Studying DNA rotations proves that the type of inserted nucleobase can be clearly determined under this condition. The proposed method can truly classify any unknown DNA bases into one of the possible classes adenine, cytosine, guanine, and thymine if the signal-to-noise ratio is greater than 12 dB. Our first principle study reveals that interband plasmons in GQD nanopores are applicable as a new sequencing mechanism for DNA nucleobases.