Spectroscopic and Electrochemical Detection of Thrombin/5'-SH or 3'-SH Aptamer Immobilized on (porous) Gold Substrates

Abstract

Thrombin is a serine protease that catalyzes the conversion of soluble fibrinogen to insoluble fibrin, and thus induces physiological and pathological blood coagulation. Therefore, it is important to detect thrombin in blood serum for purposes of diagnosis. To achieve this goal, it has been suggested that a 15-mer aptamer strongly binds with thrombin to form a G-quartet structure of the aptamer. Generally, 5'-end thiol-functionalized aptamer has been used as an anti-thrombin binder. Herein, we evaluate the possibility of utilizing a 3'-SH aptasensor for thrombin detection using SPR spectroscopy, and compare the enhancement of the electrochemical signal of the thrombin-aptamer bound on a porous gold substrate. Although the two aptamers have similar configurations, in SPR analysis, the 3'-SH aptamer was a effective aptasensor as well as 5'-SH aptamer.Results from electrochemical analysis showed that the porous gold substrate acted as a good substrate for an aptasensor and demonstrated 5-fold enhancement of current change, as compared to gold thin film.

Waveguide-Mode Sensors as Aptasensors

“…[ 44 ]. Recently, based on spectroscopic and electrochemical detection, attempts were made to compare 5′ and 3′ thiolated aptamers on porous gold substrates and it showed higher sensivity compared to the thin gold film substrates [ 45 ]. Aptamers are also harnessed in the assay known as Aptamer Linked Immunosorbent Assay (ALISA), analogous to the same format Enzyme Linked Immunosorbent Assay (ELISA) [ 46 , 47 ].…”

Non‐isothermal crystallization behavior of PLA/acetylated cellulose nanocrystal/silica nanocomposites

“…Discarded after use, PLA decomposes to H 2 O or CO 2 , which can be nutrients for the biomass. This circulation of resources can be expressed as up . The mechanical strength and stiffness of biodegradable PLA makes it suitable for the packaging, medical and automotive fields.…”