Utilizing armchair and zigzag nanoribbons for improved detection of SO2 Toxicity with graphene biosensor

초록

Graphene nanoribbons (GNRs), with their distinctive structural and electronic characteristics, offer significant potential for use as biosensors in the detection of sulfur dioxide (SOS) levels. This study employs Density Functional Theory (DFT) to evaluate the sensitivity of armchair graphene nanoribbons (AGNRs) to SOS gas. Specifically, we investigate the influence of SOS molecules on the electronic and transport characteristics of both pure and Cr-doped zigzag graphene nanoribbons (ZGNRs) and Cr-doped AGNRs. Key electronic properties, including band structure, adsorption energy, and density of states (DOS), were analyzed following SOS adsorption. The results indicate that Cr doping leads to significant changes in the electronic properties of AGNRs upon SOS exposure, including alterations in the Fermi surface that result in band separation and the formation of a forbidden band. The adsorption energy of Cr-doped AGNR increased from 0.07 eV (pristine AGNR) to 0.55 eV (Cr-doped AGNR), nearly eight times higher, indicating strong chemisorption of SOS. These findings suggest that Cr-doped AGNRs exhibit high sensitivity to SOS, making them promising candidates for gas detection. Furthermore, this study reveals that SOS adsorption in the armchair direction results in a more pronounced peak-tovalley ratio compared to the zigzag direction, highlighting distinct characteristics in SOS adsorption behavior. These findings could facilitate the development of advanced sensors with improved sensitivity and selectivity for environmental monitoring and safety applications.

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