Cost-effective and rapid biosensor with background free chemiluminescence (CL) detection was developed using ssDNA aptamer-conjugated 6-FAM fluorescein (DAF), graphene oxide bound with magnetic nanoparticle (GMN), and 3,4,5-trimethoxyphenylglyoxal (TMPG). When thrombin was incubated in TE buffer (pH 7.5) containing 200 nM DAF for 10 minutes, thrombin binds strongly to DAF. Free DMF, which does not bind with thrombin in the solution, binds with GMN through the - interaction between the DAF and GMN. Thus, we were able to remove DMF-bound GMN in the solution using a magnetic bar. When thrombin-bound DMF was mixed with TMPG (0.1 M) in the presence of tetrapropylammonium hydroxide (0.01 M), strong CL was observed based on the chemiluminescence resonance energy transfer from high-energy intermediate formed from the reaction of TMPG and guanine, the main base of DAF, to 6-FAM. The background-free biosensor having excellent accuracy and precision was more sensitive than conventional and time-consuming analytical methods.
Journal: TechConnect Briefs
Volume: 1, Nanotechnology 2013: Advanced Materials, CNTs, Particles, Films and Composites (Volume 1)
Published: May 12, 2013
Pages: 711 - 712
Industry sector: Advanced Materials & Manufacturing
Topics: Advanced Materials for Engineering Applications