Gold nanoparticle-based signal enhancement of an aptasensor for ractopamine using liquid crystal based optical imaging
The authors report on a method for the determination of ractopamine (RAC) via liquid crystal (LC) optical imaging and gold nanoparticle-induced signal enhancement. The gold nanoparticles (AuNPs) were blended with the desired concentrations of RAC, and this is found to strongly improve the performance of the assay. The RAC aptamers were immobilized on the self-assembled film of a glass slide for specific recognition of RAC. This causes a homeotropic re-orientation of the LCs. Notably, the aptamers need not be immobilized on the nanoparticles like in other methods. The addition of RAC causes the formation of an AuNP-RAC-aptamer conjugate on the sensing interface. This disrupts the orientation of LCs and results in a change of the polarized images of the LCs. The method has a detection limit as low as 1 pM of RAC.
KeywordsAptamer Biosensor Self-assembled film Glass slide Recognition Conjugate Sensing interface Orientation Polarized image Homeotropic re-orientation
This work is financially supported by the Doctoral Research Startup Foundation of Jining Medical University, the Natural Science Foundation of Chongqing (CSTC2015JCYJA20014) and Ministry of Education (CQKLBST-2515005).
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Conflict of interest
The authors declare that they have no conflict of interest.
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