Development of biosensors for the detection of oversulfated chondroitin sulfate (OSCS), the key contaminant in heparin (Hep), is a greatly demanding but challenging task. In this work, a FRET system for the detection of OSCS was successfully constructed by using supercharged green fluorescent protein (ScGFP) as the energy donor and dye labelled Hep (Hep-RF1) as the energy acceptor. With heparinase treatment, Hep-RF1 was hydrolyzed into small fragments, resulting in quenching of the FRET signal. On the other hand, since OSCS is an inhibitor for heparinase, the presence of OSCS would enable the effective FRET from ScGFP to Hep-RF1 even after heparinase treatment. With this ScGFP based FRET sensing platform, as low as 0.001% (w/w) OSCS in Hep has been successfully detected.

中文翻译：

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基于增压荧光蛋白的FRET传感平台，可检测肝素污染

开发用于检测肝素（Hep）中的关键污染物过硫酸盐硫酸软骨素（OSCS）的生物传感器是一项非常艰巨但具有挑战性的任务。在这项工作中，通过使用增压绿色荧光蛋白（ScGFP）作为能量供体和染料标记的Hep（Hep-RF1）作为能量受体，成功构建了用于OSCS检测的FRET系统。肝素酶处理后，Hep-RF1水解成小片段，导致FRET信号淬灭。另一方面，由于OSCS是肝素酶的抑制剂，所以即使存在肝素酶治疗后，OSCS的存在也可使有效的FRET从ScGFP变为Hep-RF1。有了这个ScGFP 基于FRET的FRET传感平台，已成功检测到Hep中低至0.001％（w / w）的OSCS。