Predicting fish spoilage through adsorption and detection of volatile sulfur compounds on B2N monolayers: a computational study

In the present work, a comprehensive density functional theory (DFT) investigation was conducted to elucidate the adsorption behavior of two key sulfur-containing volatile compounds generated during fish deterioration, namely dimethyl sulfide (DMS, CH₃–S–CH₃) and dimethyl disulfide (DMDS, CH₃–S–S–CH₃). The calculated adsorption energies are significantly negative, revealing strong yet reversible adsorption characteristics suitable for both sensing and capture applications. The obtained E ads (%ΔE g ) values for DMS/B₂N and DMDS/B₂N are − 0.47 eV (40%) and − 0.45 eV (39%), respectively. Adsorption induces substantial modulation of the B₂N electronic band gap, generating distinct electronic responses for each analyte. As a result, the monolayer exhibits distinct electronic and φ-type sensing responses, arising from substantial band-gap modulation and charge transfer between the adsorbed species and the B₂N substrate, thereby providing a pronounced and readily detectable electrical response. The pristine B₂N surface exhibits high sensitivity toward both DMS and DMDS, while the short recovery times and ultrafast desorption confirm excellent reversibility. Therefore, the B₂N monolayer serves as a multifunctional nanomaterial, acting as both a high-performance sensor and an efficient adsorbent for sulfur-based spoilage compounds, and presents a promising strategy for real-time seafood freshness monitoring.