Evaluation of the alkyl chain length and photocatalytic antibacterial performance of cation g-C3N4

Abstract

Several cation graphite carbon nitrides (g-C₃N₄-(CH₂)_n-ImI⁺) were synthesized by chemically attaching imidazolium appended alkane chains with different lengths (n = 2, 4, 8, 12 and 16) to g-C₃N₄. The introduction of a cation segment potentially improved the interaction between the carbon material and Gram negative (MDR-A. baumannii) and Gram positive (S. aureus) bacteria as characterized by ζ potential measurement. Short alkane chain (carbon numbers of 2, 4 and 8) carbon materials displayed relatively stronger bacterial interactions compared to long alkane chain bearing ones (n = 12 and 16). In addition, short chain carbon materials (g-C₃N₄-(CH₂)₄-ImI⁺) displayed relatively higher photocatalytic reactive oxygen species (¹O₂, ˙O₂⁻ and ˙OH) production efficiency. Bacterial interaction and ROS production efficiency synergistically contribute to photocatalytic antibacterial performance. The current data revealed that g-C₃N₄ with short flexible cations attached exhibited bacterial interaction and ROS production. Among these synthesized materials, g-C₃N₄-(CH₂)₄-ImI⁺ exhibited the most pronounced photocatalytic antibacterial efficiency (>99%).