Summary: | 碩士 === 國立臺灣海洋大學 === 生物科技研究所 === 98 === In this thesis we describe two gold nanoparticles (Au NPs)-based probes for sensing of thrombin, lead ions (Pb2+) in real sample. (1) Thrombin Sensor: We developed a simple, rapid, label-free, homogenous assay—using fibrinogen and Au NPs—for the highly selective and sensitive detection of thrombin. Thrombin-mediated cleavage of fibrinogen leading to formation of fibrin, which has a long chain polymer structure of several micrometers (mm). The presence of fibrin, caused aggregation of the Au NPs, leading to decreased surface plasmon resonance (SPR) absorption at 520 nm. Our assay is relatively sensitive and specific for the detection of thrombin and Factor Xa at picomolar levels in plasma samples. (2) Lead ions Sensor: This Pb2+ sensor was developed that based on the Pb2+ ions accelerated the leaching rate of Au NPs by thiosulfate (S2O32–) and 2-mercaptoethanol (2-ME). The 2-ME/S2O32–-Au NP probe is highly sensitive (LOD = 0.5 nM) and selective (by at least 1000-fold over other metal ions) toward Pb2+ ions, with a linear detection range (2.5 nM-10 mM) over nearly four orders of magnitude. The cost-effective probe allows rapid and simple determination of the concentrations of Pb2+ ions in environmental samples (Montana soil and river); with results showing its great practicality for the detection of lead in real samples.
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