Key Laboratory of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University , Chengdu 610031, PR China.
ACS Appl Mater Interfaces. 2017 Feb 1;9(4):3400-3410. doi: 10.1021/acsami.6b14118. Epub 2017 Jan 18.
"Turn-on" or "turn-off" probes remain challenges in the establishment of sensitive, easily operated, and reliable methods for in situ monitoring bioactive substances. In the current study, electrospun fibrous strips are designed to provide straightforward observations of ratiometric color changes with the naked eye in the presence of serum heparin or urine trypsin. A tetraphenylethene (TPE) derivative is constructed and along with phloxine B is grafted on fibers, followed by protamine adsorption to induce static quenching of phloxine B and aggregation-induced emission of the TPE derivative. The presence of heparin or trypsin removes protamine to restore the fluorescence of phloxine B at 574 nm (I) and relieve the emission of the TPE derivative at 472 nm (I). The grafting densities of phloxine B and the TPE derivative are essential to achieve the optimal fluorescence-intensity ratio of I/I for the ratiometric detection of heparin and trypsin. Under illumination by an ultraviolet lamp, the fibrous mats turn from cyan to green in the presence of heparin at 0.4 U/mL and to a bright yellow at 0.8 U/mL, which is feasible in sensing serum heparin levels during postoperative and long-term care of patients after cardiovascular surgery. The protamine digestion results in similar color transitions with increasing trypsin levels up to 8 μg/mL, indicating the potential for monitoring urine trypsin levels of pancreas transplant patients. The color strips based on the ratiometric fluorescent response indicate advantages in lowering the detection limit and improving the accuracy and reproducibility, bearing great potential for a real-time and naked-eye detection of bioactive substances as self-test devices.
“开启”或“关闭”探针在建立用于原位监测生物活性物质的敏感、易于操作和可靠方法方面仍然是一个挑战。在本研究中，设计了电纺纤维条，以便在存在血清肝素或尿液胰蛋白酶的情况下，用肉眼直接观察到比率比色变化。构建了四苯乙烯（TPE）衍生物，并将其与荧光素 B 接枝到纤维上，然后吸附鱼精蛋白以诱导荧光素 B 的静态猝灭和 TPE 衍生物的聚集诱导发射。肝素或胰蛋白酶的存在去除鱼精蛋白，以恢复 574nm（I）处的荧光素 B 的荧光，并缓解 472nm（I）处 TPE 衍生物的发射。荧光素 B 和 TPE 衍生物的接枝密度对于实现肝素和胰蛋白酶比率检测的最佳荧光强度比 I/I 至关重要。在紫外灯下照射时，纤维垫在 0.4 U/mL 肝素存在下从青色变为绿色，在 0.8 U/mL 时变为亮黄色，这在心血管手术后患者的术后和长期护理期间监测血清肝素水平时是可行的。随着胰蛋白酶水平的增加，鱼精蛋白消化导致类似的颜色转变，直至 8μg/mL，表明监测胰腺移植患者尿液胰蛋白酶水平的潜力。基于比率荧光响应的彩色条带在降低检测限、提高准确性和重现性方面具有优势，有望成为用于实时和肉眼检测生物活性物质的自我检测装置。
