Doped C20 fullerenes as a new generation of efficient nanosorbents and nanosensors for rapid detection of dimethyltryptamine in drug detection

The quick and accurate identification of the powerful psychoactive compound Dimethyltryptamine (DMT) is still a significant drawback in forensic science and investigation concerning clinical toxicology. To overcome the issues associated with classical analytical instrumentation, a novel class of innovative highly sensitive nanosensors based on pristine and doped C₂₀ fullerenes is presented. Using a heavy computational workflow grounded in Density Functional Theory (DFT) at the computational level B3LYP-D3/6-311G(d, p) in the CPCM solvation model (water phase), we systematically examined the sensing properties of pristine C₂₀, and the boron (BC₁₉), germanium (GeC₁₉), and silicon-doped (SiC₁₉) C₂₀ fullerenes to DMT. We use calculated values based on theoretical properties relating to the performance (adsorption energy (Eads), HOMO-LUMO gap (HLG), electrical conductivity (σ), and recovery time (τ)). According to the data, each nanomaterial will have its own unique and promising applications. The BC₁₉ and SiC₁₉ nanostructures presented extremely strong adsorption energies for DMT of -40.78 kcal.mol^{- 1} and - 18.82 kcal.mol^{- 1}, respectively, and recovery times that indicated effectively irreversible binding. The combination of high Eads and negligible responsibility change in electrical conductivity of BC₁₉ and SiC₁₉ suggests they would work well as candidates for adsorption and removal applications where stable analyte capture is desired. On the other hand, the GeC₁₉ nanosensor showed an unprecedented and selective response, with adsorption of DMT leading to remarkable increases in the electrical conductivity of the nanomaterial of over 16 orders of magnitude, from 3.4 × 10^{- 15} S.m^{- 1} to 1.9 × 10² S.m^{- 1} while exhibiting a relatively strong adsorption energy of -25.75 kcal.mol^{- 1}. This unique alteration identifies GeC₁₉ as the top-performing disposable electrochemical sensor for fast, sensitive, and selective detection of DMT. These interactions were also confirmed by NBO, NCI, and QTAIM analyses, which indicated strong charge transfer (NBO), attractive non-covalent interactions (NCI), and medium strength hydrogen bonding (QTAIM) in the BC₁₉@DMT, GeC₁₉@DMT, and SiC₁₉@DMT complexes, respectively. This work not only provides the first theoretical evidence for C₂₀-based DMT detection, but also provides a clear pathway for experimental imagining of novel, task-specific nanosensors with important implications for future applications in forensic and point-of-care diagnostics.