A New Electrochemical Host-Guest Recognition Sensor for DNA Detection

Abstract

This communication reports on a new electrochemical method to detect the hybridization specificity in homogenous solution by using host-guest recognition technique. A hairpin DNA with a dabcyl molecule which is typical guest molecule to b-CD at the 3’-terminus and a NH2 linked at the 5’-terminus as the probe DNA. The probe DNA was immobilized on the PdS nanoparticle to construct a double-labeled probe (DLP) and could selectively hybridize with its target DNA in homogenous solution. A b-CD modified Poly(N-acetylaniline) glassy carbon electrode was used for capturing dabcyl in DLP. Without binding with target DNA, the DLP keep stem-loop structure and block dabcyl enter into the cavity of b-CD on electrode. However, a target-binding DLP is incorporated into double stranded DNA, causing loop-stem structure opened and dabcyl could be easy captured by b-CD which brought DLP on electrode surface. With electrochemical measurement, the signal come from Pd2+ be used for target DNA quantitative analysis.