Molecular modeling of B24O24 scaffolds for the electrochemical sensing and detection of nitrosourea and hydroxyurea drugs: Insight from DFT calculations

Hydroxyurea (HU) and nitrosourea (NU) are well-known chemotherapeutic medications. Still, their efficiency is limited due to the possibility of their misuse and the emission of small quantities of unmetabolized drugs into the environment. Many side effects might occur from taking these drugs. Nanomaterials for drug detection are crucial in pharmaceutical research, especially in cancer therapy applications like HU and NU. This work aimed to examine the sensitivity of B24O24 nanocage for detecting HU and NU drugs by using density functional theory (DFT). We studied the interactions between HU/NU drugs and the B24O24 nanocage using optimized geometries, adsorption energies, FMO, NCI, NBO and QTAIM analyses by employing DFT and TD-DFT at the B3LYP-D3/6-31G(d,p) level of theory. Specifically, the adsorption energy estimates of -32.06kcal/mol for the NU@B24O24 -1(& lowast;) complex and -28.79kcal/mol for the HU@B24O24 -5 complex show that the HU/NU drugs are firmly adsorbed onto B24O24 and that the process is exothermic. Through NCI and QTAIM analyses, noncovalent interactions, mainly the van der Waals forces, have been observed between B24O24 and the HU/NU drugs. When HU/NU interacts with the surface of B24O24, new energy levels are formed in the B24O24 PDOS. After analyzing the Eg value, sensitivity and recovery time as indicators of the B24O24 nanocage sensing capability, it was found that the NU@B24O24 -2 & lowast; complex exhibited the best conductivity (3.94x1012S/m), fine sensitivity (4.74x10-1) and most minor stability due to its small energy gap value of 3.47eV. However, the most stable complex is HU@O-24(24)-3, which has an energy gap of 5.08eV. At a value of 1.0901x10-9s, the complex NU@B24O24 -4 & lowast; has the quickest recovery time. As a result of its rapid recovery time, the B24O24 nanocage is highly desirable for its potential application as an HU/NU drug sensor. This proves that HU/NU drugs can be effectively detected by the B24O24 nanocage. Our results suggest that the B24O24 nanocage has the potential to improve drug detection (HU/NU), suggesting potential avenues for further progress.