Fig. 1.

Detection of human α-thrombin. (A) AuNP probes functionalized with TBA-29 and the Raman label NBT capture the target in solutions that contain various concentrations of thrombin and a nontarget protein, albumin. These assemblies are in turn captured by a film functionalized with MB-labeled TBA-15 to form SERS hot spots. Spectral data are collected within a designated area of the gold film by raster scanning under a Raman microscope with a 633-nm incident laser. (B) The collection of spectral data per each concentration of thrombin tested is analyzed by CLS regression to determine the contribution of each reporter to the spectra and thereby determine true protein-binding events vs. false positives. Physical locations of true- and false-positive binding events are represented in a heat map.