HIGH-SENSITIVITY ASSAYS FOR PATHOGEN DETECTION USING METAL-ENHANCED FLUORESCENCE

摘要

The invention provides an assay method and kit for detecting a target pathogen in a sample, the method comprising:
a) providing a system comprising:
a layer of immobilized metal particles positioned on a surface substrate, wherein the immobilized metal particles have attached thereto an immobilized capture DNA sequence probe complementary to a known DNA sequence of the target pathogen; and
a free capture DNA sequence probe complementary to a known DNA sequence of the target pathogen, wherein the free capture DNA sequence probe has attached thereto a fluorophore;
b) contacting the sample with the immobilized capture DNA sequence probe, wherein the DNA sequence of the target pathogen binds to the immobilized capture DNA sequence probe;
c) contacting the bound DNA sequence of the target pathogen with the free capture DNA sequence probe, wherein binding of the free capture DNA sequence probe to the DNA sequence of the target pathogen causes the fluorophore to be positioned a sufficient distance from the immobilized metal particles to enhance fluorescence emission when excited by an irradiating source; and
d) identifying the target pathogen by fluorescence emission by irradiating the system with an irradiating source to excite the fluorophore.