Photoresponsive CuS@polyaniline nanocomposites: An excellent synthetic bactericide against several multidrug-resistant pathogenic strains

Abstract

Surface modification can optimize the antibacterial properties of inorganic materials; however, their high-cost, lengthy synthesis, and limited efficacy remain challenges in combating antibiotic resistance. Herein, we employed a rapid and...

Ultrathin TiS2@N,S-Doped Carbon Hybrid Nanosheets as Highly Efficient Photoresponsive Antibacterial Agents

“…The photogenerated electron–hole pairs play a crucial role in cytotoxic ROS generation. During the photochemical reduction of surface-adsorbed molecular oxygen (O 2 ), the TiS 2 @NSC LAA hybrid photocatalyst is extremely reactive in aqueous solution and can produce multiple cytotoxic ROS, including superoxide anion radicals ( • O 2 – ), hydroxyl radicals (OH • ), and singlet oxygen ( 1 O 2 ), as illustrated in the following relationship: , normalO 2 → O 2 • − ↔ OH • ↔ O 2 1 The interaction of the above reactive radicals with the cellular components of bacteria leads to a potent cytotoxic effect and disruption of the bacterial cell membranes. ,, Understanding the antibacterial mechanism behind the growth suppression of bacteria is crucial, and numerous descriptive reports exist that elucidate the cytotoxicity of various nanomaterials against MDR microbes. ,, The primary antibacterial mechanism to combat bacterial growth involves direct interaction of the nanomaterials with the bacterial cell membranes, which physically disrupts the bacterial cell membrane, causing the leakage of cellular contents and eventually suppressing bacterial growth. In this case, the particle size, structural morphology, and surface area of the materials are important factors that can influence their bactericidal efficacy .…”

“…Importantly, the comprehensive details and methods regarding the in silico molecular docking studies are described in our prior publication. 21 Conclusively, the TiS 2 @NSC LAA hybrid NSs demonstrate outstanding antibacterial efficacy against both Gram-positive S. aureus and Gram-negative E. coli pathogenic bacteria. This remarkable performance can be attributed to the synergistic effects of the components in the system, allowing their direct interaction with the bacterial species, leading to the generation of multiple cytotoxic ROS under visible-light irradiation, and piercing action due to its ultrathin dimension, resulting in multimechanistic cytotoxicity and damage to bacterial cells.…”

“…The characteristic fluorescence effect observed in Figure 4d is the result of the chemical reaction between OH • radicals and 3-CCA molecules, which strongly generates 7hydroxycoumarin-3-carboxylic acid molecules. 21 Accordingly, the reaction mixture containing TiS 2 @NSC LAA and 3-CCA produced 7-hydroxycoumarin-3-carboxylic acid molecules under visible-light illumination (Figure 4d), and the observed fluorescence tendency was enhanced with an increase in the applied radiation dose (J), indicating the existence of OH • radicals in the system. 50 Conversely, the fluorescence intensity of the samples that were not illuminated (kept in the dark) or the samples containing only TiS 2 @NSC LAA or 3-CCA remained unchanged compared to the illuminated samples.…”

“…50,62,63 Furthermore, the TEM results (Figure 7b) reveal that the membrane structure integrity of both bacterial species exhibits aggregated The interaction of the above reactive radicals with the cellular components of bacteria leads to a potent cytotoxic effect and disruption of the bacterial cell membranes. 44,21,50 Understanding the antibacterial mechanism behind the growth suppression of bacteria is crucial, and numerous descriptive reports exist that elucidate the cytotoxicity of various nanomaterials against MDR microbes. 19,63,64 The primary antibacterial mechanism to combat bacterial growth involves direct interaction of the nanomaterials with the bacterial cell membranes, which physically disrupts the bacterial cell membrane, causing the leakage of cellular contents and eventually suppressing bacterial growth.…”

“…14,16 Despite their superior antibacterial properties, the strong toxicity of the Ag NPs to human cells and their intractable abuse often leads to adverse effects such as argyrosis, spasms, and gastrointestinal disorders, 17 and the ultraviolet (UV)-light-induced biocidal activity of such photocatalysts hampers their applications in biological therapies. 18 In contrast, transition-metal sulfides (TMSs) represent several distinct benefits in reduced acute toxicity, acceptable biocompatibility, and high stability toward metal leakage without causing any harmful effects due to the excessive metal ions and they possess multiple microbial killing mechanisms, 19 among which MoS 2 and CuS have been extensively investigated as excellent antimicrobial photocatalysts, 20,21 whereas other TMSs including Ag 2 S, 22 CdS, 23 Bi 2 S 3 , 24 FeS 2 , 25 SnS, 26 TiS 2 , 27 WS 2 , 28 and so forth are attracting increasing research interest as alternative biologically active agents. Typically, TiS 2 , known for its abundance and lightweight nature, has primarily been explored for electronic and energy storage purposes.…”