建立了多重标记模板分子提高分子印迹电化学传感器灵敏度的方法.通过修饰有大量二茂铁甲酸的树枝状大分子标记的赤霉素与样品中的赤霉素分子之间的竞争反应来进行定量测定.由于实现了二茂铁甲酸的多重标记,故测量电信号得到了明显放大,灵敏度显著提高,线性范围为2.0×12-9 ~ 1.2×12-7 mol/L,检出限达9.3×12-10 mol/L.本方法已成功用于啤酒样品中赤霉素测定.
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-acetie 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 2.0xlO-9 to 1.0x10-7 mol/L, with a detection limit of 9.3x10^-10 moL/L. In addition, the sensor had good reproducibility and its feasibility was verified in the analysis of series of real beer samples.