The photocatalytic antibacterial method is one of the most effective and “green” methods for treating multidrug resistant (MDR) bacteria-caused infections. The most critical scientific question is how to improve the antibacterial efficiency of photosensitizers (PS). Herein, an organic-conjugated-polymer photocatalyst poly((E)-5-(2,5-dihydroxy-4-methylphenyl)-5′-(2-(5-methylthiophen-2-yl)vinyl)-[2,2'-bithiophene]-4-carboxylic acid) (PTH-COOH-(OH)₂) has been successfully synthesized. A new route for developing highly active organic-conjugated-polymer photocatalysts for environmental purification via the proper expansion of the backbone conjugate structure and the introduction of effective groups such as carboxyl and hydroxyl groups is proposed. The visible-light photocatalytic activities of PTH-COOH-(OH)₂ were evaluated against methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus epidermidis (S. epidermidis) and Escherichia coli (E. coli) under LED white light. A very high antimicrobial efficiency was achieved for optimized 0.3 mg mL⁻¹ PTH-COOH-(OH)₂ under visible light illumination. Over 7 log of MRSA was killed in 3 h, 7 log of S. epidermidis was killed in 3 h, and 93.3% decomposition of E. coli was achieved in 3 h. These photoantimicrobial effectiveness values are among the most widely published for conjugated polymer photocatalysts. The findings of trapping studies and electron spin resonance (ESR) spectroscopic investigations indicated that during the photocatalytic antimicrobial process, ·OH, ¹O₂, ·O₂⁻, and e⁻ are largely reactive oxygen species (ROS). Importantly, following recycling processes, the PTH-COOH-(OH)₂ photocatalyst demonstrated satisfactory stability and excellent photocatalytic activity.

Graphical Abstract

The organic-conjugated-polymer photocatalysts poly((E)-5-(2,5-dihydroxy-4-methylphenyl)-5′-(2-(5-methylthiophen-2-yl)vinyl)-[2,2′-bithiophene]-4-carboxylic acid) (PTH-COOH-(OH)₂) is successfully synthesized using the Stille coupling reaction. PTH-COOH-(OH)₂ exhibits more outstanding photocatalytic antibacterial activity and stability, and has broad-spectrum antibacterial efficacy that can kill Gram-positive bacteria (MRSA, Staphylococcus epidermidis) and Gram-negative bacteria (Escherichia coli) under visible light irradiationtreat. The highly photocatalytic antibacterial active is developed via the proper expansion of the backbone conjugate structure and the introduction of effective groups such as carboxyl and hydroxyl groups.

中文翻译：

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新型聚噻吩共轭聚合物光催化剂在可见光下杀死多重耐药细菌

光催化抗菌方法是治疗多重耐药（MDR）细菌引起的感染的最有效和“绿色”方法之一。最关键的科学问题是如何提高光敏剂（PS）的抗菌效率。在此，有机共轭聚合物光催化剂聚((E)-5-(2,5-二羟基-4-甲基苯基)-5'-(2-(5-甲基噻吩-2-基)乙烯基)-[2，成功合成了2'-联噻吩]-4-羧酸)(PTH-COOH-(OH) _{2 )。}提出了一种通过主链共轭结构的适当扩展和引入羧基和羟基等有效基团来开发用于环境净化的高活性有机共轭聚合物光催化剂的新路线。PTH-COOH-(OH)的可见光光催化活性₂在 LED 白光下针对耐甲氧西林金黄色葡萄球菌( MRSA )、表皮葡萄球菌( S. epidermidis ) 和大肠杆菌( E. coli )进行了评估。^{优化的0.3 mg mL -1} PTH-COOH-(OH) ₂在可见光照射下实现了非常高的抗菌效率。3小时杀灭7log以上MRSA ， 3小时杀灭7log表皮葡萄球菌，93.3%分解大肠杆菌3小时内就实现了。这些光抗菌功效值是共轭聚合物光催化剂中发表最广泛的值之一。捕获研究和电子自旋共振（ESR）光谱研究的结果表明，在光催化抗菌过程中，·OH、¹ O ₂、·O ₂ ^-和e ^-主要是活性氧（ROS）。重要的是，在回收过程中，PTH-COOH-(OH) ₂光催化剂表现出令人满意的稳定性和优异的光催化活性。

图形概要

有机共轭聚合物光催化剂聚((E)-5-(2,5-二羟基-4-甲基苯基)-5'-(2-(5-甲基噻吩-2-基)乙烯基)-[2,2'利用Stille偶联反应成功合成了[ -联噻吩]-4-羧酸)(PTH-COOH-(OH) _{2 )。}PTH-COOH-(OH) ₂表现出更优异的光催化抗菌活性和稳定性，具有广谱抗菌功效，可杀灭革兰氏阳性菌（MRSA、表皮葡萄球菌）和革兰氏阴性菌（大肠杆菌）可见光照射下处理。通过主链共轭结构的适当扩展以及羧基和羟基等有效基团的引入，开发出高光催化抗菌活性。