Highly sensitive detection of thrombin using metal-waveguide-capillary based photometer and gold nanorods probe

Abstract This work described a sensitive thrombin analysis method employing metal-waveguide-capillary (MWC) photometry with a sandwich aptamer- gold nanorods (GNRs) as a signal transporting probe. The sandwich aptasensor consisted of a pair of thrombin-binding aptamers: one 29-mer aptamer modified with magnetic beads as capture aptamers; and one 15-mer aptamer binding with GNRs as report aptamers. Through the measurement of GNRs from the sandwich complex, the MWC photometry enabled to detec t thrombin with a linear range from 0.068 nM to 1.09 nM, and with a detection limit as low as 0.02 nM. The detection limit was improved 68-fold vs. that of commercial spectrophotometer with 1 cm cuvette.