基于DNA-银纳米颗粒比色法高灵敏度检测过氧化氢和葡萄糖

The Highly Sensitive Detection of Hydrogen Peroxide and Glucose Based on DNA-stabilized Silver Nanoparticles Colorimetric Biosensor

建立一种基于DNA-银纳米颗粒(DNA-AgNPs)高灵敏比色传感器检测过氧化氢和葡萄糖的方法。在DNA保护下,用硼氢化钠还原硝酸银合成DNA-AgNPs,加入过氧化氢后其溶液颜色由黄褐色变为无色,从而实现过氧化氢的比色法检测。葡萄糖氧化酶催化葡萄糖氧化生成过氧化氢,利用此方法可间接测定葡萄糖的含量。在优化试验条件下,对过氧化氢和葡萄糖的检测限为分别为0.36μmol/L和1.13μmol/L。以梨汁为实际样品,通过标准加入法测定葡萄糖含量,加标样品的回收率范围在87.00%~96.02%。该方法实现了食品中过氧化氢和葡萄糖的快速、可视化检测,提高了检测的精确性和灵敏度,为构建食品中目标物的检测方法提供了参考。

In this study,a colorimetric biosensor based on DNA-stabilized silver nanoparticles(DNA-AgNPs) has been developed for highly sensitive detection of hydrogen peroxide and glucose levels in pear juice.DNA-AgNPs were synthesized by reduction of AgNO3 with NaBH4 under protecting of random oligonucleotide.The DNA-AgNPs has a characteristic absorption peak located at 424 nm.In the presence of hydrogen peroxide or glucose/glucose oxidase,DNA-AgNPs could be etched into smaller particles with decreasing absorbance.The solution color correspondingly changed with concentration of hydrogen peroxide or glucose,which could be directly distinguish by naked eyes.Under the optimized conditions,the limit of detection(LOD) towards hydrogen peroxide and glucose reached as low as 0.36 μmol/L and 1.13μmol/L(S/N=3) respectively.The potential application of the developed biosensing system was evaluated with peach juice as real sample.The provided strategy could serve as a prototype for developing assays in food analysis.