ABSTRACT
A novel strategy employing dendrimer to multi-label the template molecule to improve the sensitivity of molecularly imprinted electrochemical sensor was proposed. The determination relies on a competition reaction between poly ( diethylene-triaminepenta-acetic acid )-glycol ester ( PDTPA )-ferrocene-carboxylic acid ( FcA ) labeled gibberellins acid 3 ( GA3 ) and GA3 in the sample. Since one cavity corresponds with multiple FcA, instead of only one FcA, the intensity of the detecting signal was greatly enhanced, so was the sensitivity of the sensor. Experimental results showed that the molecularly imprinted electrochemical sensor was sensitive to GA3 detection at a concentration from 2. 0í10-9 to 1. 0í10-7 mol/L, with a detection limit of 9. 3í10-10 mol/L. In addition, the sensor had good reproducibility and its feasibility was verified in the analysis of series of real beer samples.
