Electrochemiluminescence Biosensor Based on DNAzyme and 3,4,9,10-Perylenetetracarboxylic Dianhydride Derivative Functionalized Hollow Gold Nanoparticles for Detection of Lead Ions
Based on target cycling amplification and 3,4,9,10-perylenetetracarboxylic dianhydride derivative functionalized singal probe,an ultrasensitive electrochemiluminescence( ECL) sensor was designed for the detection of lead ions. The hairpin substrate DNA was immobilized on the electrode through molecular selfassembly. In the presence of Pb2+and DNAzyme,the substrate was cleaved with single strand DNA fragments left on the electrode surface. Meanwhile,the target and DNAzyme was released for another cleaving circularly.As a result,the single strand DNA fragments hybridized with the assist hairpin probe H1,which leaded to the fabrication of H2 labeled with the 3,4,9,10-perylenetetracarboxylic dianhydride derivative functionalized hollow gold nanoparticles. With the increasing concentration of Pb2+,much more signal probe was been captured and the ECL signal of the biosensor in peroxydisulfate( S2O2!8) solution would increase. An ECL assay demonstrates that the sensor has a good linear response to Pb2+concentration in the range of1×10!12mol / L-1×10!6mol / L,with a detection limit of 1 × 10!12mol / L. The fabricated sensor shows good selectivity toward Pb2+against other common metal ions.