基于UiO-66-NH2与适配体之间荧光共振能量转移检测大米中的镉离子

Fluorescence Resonance Energy Transfer between UiO-66-NH2 and Aptamer for Cadmium Ion Detection in Rice

基于荧光共振能量转移猝灭荧光标记的Cd^(2+)适配体建立了一种简便、灵敏和准确Cd^(2+)检测的方法。通过对3种金属有机框架材料(UiO-66-NH2、MIL-101(Cr)和ZIF-8)进行实验,选出其中带正电荷数值更大、粒径适宜且在水中能稳定分散的UiO-66-NH2作为荧光猝灭剂;通过带正电的UiO-66-NH2与带负电的适配体相互作用而产生荧光共振能量转移达到荧光猝灭效果;利用Cd^(2+)与适配体的特异性相互作用,从而释放出荧光标记的适配体,并恢复荧光,以此构建一款Cd^(2+)荧光传感器。实验优化条件下建立的Cd^(2+)荧光传感器在0.01~10μmol/L范围内产生的荧光强度与Cd^(2+)浓度呈良好线性关系;该生物传感器对Cd^(2+)具有良好的选择特异性,能对实际样品中的Cd^(2+)有较好的检出能力。通过调整适配体序列能方便地研究构建其他重金属离子的荧光传感器,使得该传感器具有较好的普适性。

A simple,sensitive and accurate method for the detection of Cd^(2+)was established based on fluorescence resonance energy transfer to quench fluorescently labeled Cd^(2+)aptamers.Among three metal-organic framework materials(UiO-66-NH2,MIL-101(Cr),and ZIF-8),UiO-66-NH2,with larger positive charges,suitable particle size and stable dispersion in water,was selected as a fluorescence quencher.Fluorescence resonance energy transfer was generated by the interaction between positively charged UiO-66-NH2 and negatively charged aptamers to achieve fluorescence quenching.A fluorescent sensor for the detection of Cd^(2+)was constructed by using the specific interaction between Cd^(2+)and the aptamer to release the fluorescently labeled aptamer and restore the fluorescence.The fluorescence intensity of the sensor showed a good linear relationship with Cd^(2+)concentration in the range of 0.01–10μmol/L.The biosensor had good selectivity and specificity for Cd^(2+),and could detect Cd^(2+)in actual samples.Most importantly,by adjusting the aptamer sequence,it is convenient to explore and construct fluorescent sensors for the detection of other heavy metal ions,so the sensor has wide applicability.