本文提出了一种新颖的比色适配体传感器用于快速检测鱼肉和鹅肉中氯霉素（Chloramphenicol，CAP）。本方法的建立是基于核酸适配体特异性结合目标物的高选择性能和氧化钯纳米颗粒（PdO）标记聚合酶螯合物（EnVision，EV）的双重信号放大效应，它能特异性、灵敏性地快速检测样品中痕量氯霉素。EV上含有大约100个辣根过氧化物酶（Horseradish Peroxidase，HRP），它能够高效催化底物3,3',5,5'-四甲基联苯胺（TMB）产生颜色变化，并且PdO在一定程度上也能催化TMB出现蓝绿色，因此该方法可达到双重放大效果。同时，通过测定TMB吸光度的变化能对应计算真实样品中的氯霉素含量。结果表明，在最佳实验条件下，该方法具有较高的检测灵敏度并在0.02-150 ng/mL范围内具有良好的相关性，检测下限是0.01 ng/mL。此外，该方法已经成功地应用于分析鱼肉和鹅肉样品中的氯霉素，其结果与传统的酶联免疫吸附测定（ELISA）方法相一致。

A novel colorimetric aptasensor was developed for rapid identification of chloramphenicol (CAP) in fish and goose samples. The assay is based on a highly selective aptamer binding to its targets followed by a dual-amplification effect from large amounts of palladium oxide (PdO) nanoparticle labeled EnVision (EV). This method could detect ultra-trace amounts of CAP specifically, sensitively, and rapidly. EV has approximately 100 horseradish peroxidase (HRP) molecules and can effectively catalyze the substrate 3,3’,5,5’-tetramethylbenzidine (TMB) for color development. In addition, PdO can catalyze TMB to produce a blue-green color. Thus, a dual-amplification effect can be achieved by using the proposed method. The amount of CAP in samples can be calculated by measuring the change in the absorbance of TMB. The results indicate that, under optimal conditions, this method displays relatively high sensitivity and a good linear correlation with CAP concentration, within the range of 0.02~150 ng/mL. The lower detection limit was identified as 0.01 ng/mL. In addition, this assay was successfully used to analyze CAP concentrations in fish and goose samples, and the results were consistent with those obtained by the conventional ELISA method.

浙江省公益性项目（2014C32051）；国家支撑计划（2012BAK08B01-2），国家水禽产业体系（CARS-43-17）