Detecting specific volatile organic compounds in aquaculture monitoring using tungsten diselenide monolayers

Shrimp aquaculture has received increasing attention due to its high value and increasing consumer demands globally. However, viral infections and bacterial diseases are major causes of the loss of crops. One promising approach for bacterial disease detection at an early stage is through the detection of shrimp-health-specific volatile organic compounds (VOCs), emitted during stressed conditions. Inspired by this, we have employed first-principles density functional theory (DFT) calculations to investigate the sensing properties of pristine, vacancy-induced, and single-atom decorated tungsten diselenide (WSe₂) monolayers towards the VOCs associated with shrimp disease. Our results show that pristine and vacancy-induced WSe₂ weakly adsorbed the VOCs, with adsorption energies (E_ads) ranging from − 0.01 to − 0.54 eV. In contrast, the incorporation of single atoms of As, Ge, Fe, and Ni into WSe₂ significantly enhances the sensing properties. Notably, Ni-doped WSe₂ (Ni–WSe₂) exhibits strong adsorption with E_ads values of − 1.14, − 1.24, − 1.16, − 1.48, and − 0.98 eV for dimethylamine, trimethylamine, dopamine, histamine, and glucose, respectively, showing an efficient sensing mechanism. These desirable E_ads values are accompanied by measurable changes in the electronic properties of Ni–WSe₂, which are critical for effective detection. Charge transfer analysis, electrostatic potential, and work function calculations have further validated the enhanced sensing performance of single-atom dispersed WSe₂. Additionally, thermodynamic analysis based on the Langmuir adsorption model has been used to explore the sensing behaviour of the VOCs under varying pressure and temperature conditions. Finally, the Non-Equilibrium Green Function (NEGF) is employed for measuring the current-voltage (I–V) characteristics of pristine WSe₂ and Ni–WSe₂ monolayers upon the exposure of the VOCs. We believe that these results have the potential for the development of highly efficient WSe₂-based sensors for detecting VOCs related to infections and bacterial diseases in shrimp aquaculture.