基于空间阻滞的新型高灵敏电化学传感器检测三磷酸腺苷的研究

A Highly Sensitive Electrochemical Biosensor for Detection of Adenosine Triphosphate Based on Space Block

构建了检测ATP的新型高灵敏电化学传感器,采用扫描电镜、荧光显微镜成像技术、微分脉冲伏安法及电化学阻抗法进行表征。传感器以硅纳米颗粒通过多段DNA链与氧化铝纳米孔膜形成的三明治结构阻碍离子传导,ATP存在下,传感器中的三明治结构被破坏,使离子通道顺畅,通过检测其电流变化值达到检测目标物ATP的目的。硅纳米颗粒的应用提高了检测灵敏度,降低了背景信号;而且仅需极少量的样品即可实现对ATP的检测。结果表明,此传感器对ATP检测的线性范围为0.025~0.900 nmol/L,检出限为13 pmol/L(S/N=3)。当样品中有100倍目标物浓度的共存物质存在时,传感器仍显示出对ATP的高特异性。此传感器构建简单,再生性好,可实现对小鼠血液中痕量ATP的检测,有望应用于临床医学检测、医药工业和环境检测等领域。

In this work,a highly sensitive electrochemical biosensor for the detection of trace adenosine triphosphate( ATP) was proposed. The biosensor was based on porous anodic alumina( PAA) and SiO_2 nanoparticles combining with several oligonucleotides to construct sandwich structure. It was characterized by scanning electron microscopy,fluorescence microscopy,differential pulse voltammetry and electrochemical impedance spectroscopy,which conformed to the reliability of the biosensor fabrication and the feasibility of the detection. In the presence of ATP,the sandwich structures could be destroyed. The variation of the current was directly corresponding to the amount of the ATP. The application of SiO_2 nanoparticles could effectively reduce the background and increase the sensitivity of the biosensor. The calibration curve of ATP was obtained in the range of 0. 025-0. 900 nmol/L with the detection limit of 13 pmol/L( S/N = 3). Also,the biosensor exhibited a good specificity. Besides,the sensor was constructed easily and possessed excellent regeneration ability. The proposed biosensor was applied in detection of real sample such as mice blood. Therefore,the proposed ATP-sensing biosensor could be expected to be applied in clinical, pharmaceutical and environmental detection.