Phosphorus doped 2D polymeric graphitic carbon nitride biomaterial: Biological activity and DFT insights with nitrofuran drug interactions

Abstract

Heteroatom-doped graphitic carbon nitride (P-g-CN) has gained immense attention owing to its superior electronic and structural properties which make it suitable for biological applications. In this study, we developed phosphorous-doped graphitic carbon nitride (P-g-CN NBs) using facile thermal polymerization techniques and utilized them for potential biological activity and Density Functional Theory (DFT) studies. The as-synthesized materials were characterized and tested for their anticancer, anti-inflammatory, and antioxidant activities. The anti-cancer activity of P-g-CN NBs exhibited lower cytotoxicity and higher cell viability than undoped g-CN in HeLa cells using the MTT assay. Anti-inflammatory activity was assessed in protein denaturation inhibition studies of Bovine Serum Albumin (BSA), whereas antioxidant activity was assessed using DPPH, ABTS, Superoxide (SO), and phosphomolybdenum (PM) assays. The P-g-CN NBs exhibited excellent radical scavenging activity in DHPH and low IC₅₀ (minimum inhibitory concentration) values (56 ± 0.45 μg/mL) when compared to the IC₅₀ values of g-CN (60 ± 0.12 μg/mL). SO radical scavenging activity revealed that P-g-CN NBs exhibited superior efficiency with an IC₅₀ of 51 ± 0.14 μg/mL, compared to g-CN (IC₅₀: 60 ± 0.34 μg/mL), and was nearly equivalent to that of reference compound ascorbic acid (IC₅₀: 49 ± 0.22 μg/mL). In addition, DFT studies were conducted to understand the interactions between P-g-CN NBs and nitrofuran at the molecular level. We modelled their binding interactions with four nitrofuran compounds: Furaltadone (FTD), Furazolidone (FZD), Nitrofurantoin (NFT), and Nitrofurazone (NFZ). These findings suggest that P-g-CN NBs is safe and effective in biological and environmental applications. This study combined experimental and computational studies to highlight the versatility of P-g-CN NBs.