Suitable materials for efficient detection of colorectal cancer biomarkers: acumen from DFT

Early diagnosis of Colorectal Cancer (CRC) is crucially important for prognosis planning, curing, and saving human lives. The novel technique, which detects volatile organic compounds (VOCs) associated with CRC biomarkers in patients’ exhaled breath, has proven to be non-invasive and cost-effective. In this context, finding suitable materials to be used as a platform in nano-biosensors to detect CRC fingerprints with high sensitivity at the order of parts per billion (ppb) under ambient conditions is of great importance. In the present investigation, we explore the functionalization of boron monoxide (BO) monolayer using density-functional theory (DFT) to selectively detect CRC-related VOCs biomarkers. Four VOCs (Benzaldehyde “C₇H₆O”, Butanol “C₄H₁₀O”, Indole “C₈H₇N”, Isopropanol “C₃H₈O”) have been experimentally identified as key CRC biomarkers and are considered in this study. To improve the sensing mechanism, light metal (LM) atoms (Li, Na, K, Ca) have been selected for embedment in the pores of BO in a single-atom catalyst (SAC) fashion. The stability of the LM functionalized BO monolayer was confirmed by binding energies that exceeded the corresponding bulk cohesive energies and was further validated through ab initio molecular dynamics (AIMD) simulations at 300 K. Functionalization with LM atoms enhanced the adsorption energies of the studied VOCs compared to interfering air molecules (N₂, O₂, H₂O, CO₂). The selectivity toward VOCs was further supported by evidence of high adsorption energy, charge transfer, variations in magnetization, and changes in work function. The calculated sensor responses for the four VOCs were 2.5, 5.8, 4.0, and 6.3, respectively. Collectively, these findings highlight LM-doped BO as a promising candidate material for nano-biosensors enabling early detection of CRC biomarkers. PACs Numbers: 31.15.E-; 68.43.-h; 68.43.Fg; 82.33.Pt; 87.15.Aa; 87.15.Kg; 87.19.Xx; 87.19.xj.