Stimuli-responsive self-assembly of functional amphiphilic molecules by specific chemical stimulants is a promising strategy for sensor application. Herein, we demonstrate a fast optical detection of urea in human urine by exploiting bolaform perylene diimide functionalized with imidazoles (PDI-Hm), whose aggregation is induced by urea hydrolysis. The hydroxides produced from the enzymatic urea hydrolysis deprotonate the imidazoles to reduce electrostatic repulsion between PDI-Hm molecules in a HCl–methanol mixture, thereby leading to aggregation and consequent fluorescence quenching. The molecular interaction of PDI-Hm was further scrutinized to understand the aggregation behavior driven by the screening of electrical repulsion. As an optical sensing probe, PDI-Hm displays a prompt response (<1 min) to hydroxide and detection limit of 0.4 mM for urea. PDI-Hm incorporating urease offers considerable selectivity toward urea among various components in human urine. The urea sensing accuracy of this PDI-Hm fluorescence chemosensor is comparable to that of a clinical method, showing 93.4% consistency. Furthermore, the PDI-Hm was fabricated into a gel film allowed for the fast screening of excessive urea in urine.

中文翻译：

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聚合驱动的咪唑官能化per二酰亚胺的荧光猝灭，用于尿素检测。

通过特定的化学刺激物对功能性两亲分子的刺激响应自组装是传感器应用的有前途的策略。在本文中，我们证明了通过利用咪唑（PDI-Hm）功能化的硼化per二酰亚胺（PDI-Hm）可以快速光学检测人体尿液中的尿素，后者的聚集是由尿素水解引起的。酶促尿素水解产生的氢氧化物使咪唑去质子化，以减少HCl-甲醇混合物中PDI-Hm分子之间的静电排斥，从而导致聚集和荧光猝灭。进一步研究了PDI-Hm的分子相互作用，以了解由电斥力筛选驱动的聚集行为。作为光学传感探头，PDI-Hm显示对氢氧化物的快速响应（<1分钟），检测极限为0。尿素为4 mM。掺入尿素酶的PDI-Hm在人尿中的各种成分中对尿素具有相当大的选择性。这种PDI-Hm荧光化学传感器的尿素检测精度与临床方法相当，显示出93.4％的一致性。此外，将PDI-Hm制成凝胶膜，可以快速筛查尿中过量的尿素。