Li Xuemei, Wang Linlin, Li Chunxiang
Shandong Provincial Key Laboratory of Detection Technology of Tumor Markers, School of Chemistry and Chemical Engineering, Linyi University, Linyi 276005 (P. R. China).
Chemistry. 2015 Apr 27;21(18):6817-22. doi: 10.1002/chem.201405884. Epub 2015 Mar 12.
An ultrasensitive surface-enhanced Raman spectroscopy (SERS) sensor based on rolling-circle amplification (RCA)-increased "hot-spot" was developed for the detection of thrombin. The sensor contains a SERS gold nanoparticle@Raman label@SiO2 core-shell nanoparticle probe in which the Raman reporter molecules are sandwiched between a gold nanoparticle core and a thin silica shell by a layer-by-layer method. Thrombin aptamer sequences were immobilized onto the magnetic beads (MBs) through hybridization with their complementary strand. In the presence of thrombin, the aptamer sequence was released; this allowed the remaining single-stranded DNA (ssDNA) to act as primer and initiate in situ RCA reaction to produce long ssDNAs. Then, a large number of SERS probes were attached on the long ssDNA templates, causing thousands of SERS probes to be involved in each biomolecular recognition event. This SERS method achieved the detection of thrombin in the range from 1.0×10(-12) to 1.0×10(-8) M and a detection limit of 4.2×10(-13) M, and showed good performance in real serum samples.
一种基于滚环扩增（RCA）增强“热点”的超灵敏表面增强拉曼光谱（SERS）传感器被开发用于凝血酶的检测。该传感器包含一个SERS金纳米颗粒@拉曼标签@二氧化硅核壳纳米颗粒探针，其中拉曼报告分子通过逐层方法夹在金纳米颗粒核心和薄二氧化硅壳之间。凝血酶适配体序列通过与其互补链杂交固定在磁珠（MBs）上。在凝血酶存在的情况下，适配体序列被释放；这使得剩余的单链DNA（ssDNA）作为引物并启动原位RCA反应以产生长单链DNA。然后，大量的SERS探针附着在长单链DNA模板上，导致每个生物分子识别事件中有数千个SERS探针参与。这种SERS方法实现了在1.0×10(-12)至1.0×10(-8) M范围内对凝血酶的检测，检测限为4.2×10(-13) M，并且在实际血清样本中表现出良好的性能。
