1 research outputs found
Electrochemical Detection of Peanut Allergen Ara h 1 Using a Sensitive DNA Biosensor Based on Stem–Loop Probe
A novel electrochemical DNA sensor was developed by using
a stem–loop
probe for peanut allergen Ara h 1 detection. The probe was modified
with a thiol at its 5′ end and a biotin at its 3′ end.
The biotin-tagged “molecular beacon”-like probe was
attached to the surface of a gold electrode to form a stem–loop
structure by self-assembly through facile gold–thiol affinity.
6-Mercaptohexanol (MCH) was used to cover the remnant bare region.
The stem–-loop probe was “closed” when the target
was absent, and then the hybridization of the target induced the conformational
change to “open”, along with the biotin at its 3′
end moved away from the electrode surface. The probe conformational
change process was verified by circular dichroism (CD); meanwhile,
electron-transfer efficiency changes between probe and electrode were
proved by electrochemical impedance spectroscopy (EIS). The detection
limit of this method was 0.35 fM with the linear response ranging
from 10<sup>–15</sup> to 10<sup>–10</sup> M. Moreover,
a complementary target could be discriminated from one-base mismatch
and noncomplementarity. The proposed strategy has been successfully
applied to detect Ara h 1 in the peanut DNA extracts of peanut milk
beverage, and the concentration of it was 3.2 × 10<sup>–13</sup> mol/L