Polyion complex micellar nanoparticles for integrated fluorometric detection and bacteria inhibition in aqueous media

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• 作者：Yamin Li ; Xianglong Hu ; Sidan Tian ; Yang Li ; Guoqing Zhang ; Guoying Zhang ; Shiyong Liu
• 关键词：Polyion complex micelles ; Aggregation-induced emission ; Bacteria detection ; Macromolecular antimicrobials ; Biosensors
• 刊名：Biomaterials
• 出版年：February, 2014
• 年：2014
• 卷：35
• 期：5
• 页码：1618-1626
• 全文大小：2580 K

文摘

The development of portable and inexpensive detection methods can significantly contribute to the prevention of water-borne infectious diseases caused by pathogenic bacteria. Here we designed a nanosystem capable of both bacterial detection and inhibition, where polyion complex (PIC) micelles are constructed from negatively-charged tetraphenylethylene (TPE) sulfonate derivatives, which exhibit the aggregation-induced emission (AIE) feature, and cationic diblock copolymers, poly(ethylene oxide)-b-quaternized poly(2-(dimethylamino)ethyl methacrylate) (PEO-b-PQDMA). Upon contacting with bacteria, the PIC nanosystem disintegrates presumably due to competitive binding of polycation blocks with negatively-charged bacterial surfaces. This process is accompanied by a conspicuous quenching of TPE fluorescence emission, serving as a real-time module for microbial detection. Furthermore, the sharp decrease in CFU is indicative of prominent anti-microbial activities. Thus, PIC micelles possess dual functions of fluorometric detection and inhibition for bacteria in aqueous media. By tuning the charge density of TPE sulfonate derivatives and chain length of cationic PQDMA blocks, optimal performance against Gram-negative Escherichia coli has been achieved with a detection limit of 5.5聽脳聽10⁴聽CFU/mL and minimum inhibitory concentration (MIC) of 19.7聽渭g/mL. Tests against Gram-positive Staphylococcus aureus were also conducted to demonstrate versatility of the nanosystem.