基于适体生物传感器的碱性磷酸酯酶化学发光检测腺苷

制备了一种可用于腺苷检测的适体生物传感器,以羧基磁性微球为载体,在其表面组装腺苷适体与地高辛修饰之腺苷适体互补的核酸短链,先加入一定浓度的腺苷,再连接抗地高辛的碱性磷酸酯酶,用化学发光法检测发光值,根据腺苷加入前后化学发光强度的变化来定量检测腺苷。实验考察了羧基磁性微球用量、氨基修饰的腺苷适体用量、地高辛修饰的核酸短链用量及抗地高辛的碱性磷酸酯酶用量对体系组装和腺苷识别的影响。结果显示,优化条件下,在1.0×10~(-7)~1.0×10~(-3)mol/L范围内,腺苷浓度的对数与发光信号呈线性关系(r~2=0.976 9),定量下限为1.0×10~(-7)mol/L。与其他核苷相比,腺苷的选择特异性更好,且在稀释血清中适体对腺苷有很好的特异性识别能力。

Detection of Adenosine Based on Aptamer Biosensor with Alkaline Phosphatase Chemiluminescence Assay

A kind of aptamer biosensor was prepared to detect adenosine,with magnetic microspheres as the carrier immobilizing adenosine-binding aptamer,then assembling adenosine aptamerdigoxin labeled part-complementary strand of adenosine-binding aptamer(report DNA) on the surface.After adding adenosine,the anti-digoxin alkaline phosphatase (ALP)reacted with it,which could result in a change of chemiluminescence (CL) signal.Adenosine was quantified according to the change of the CL intensity.Factors affecting the assembly and recognition process,including amount of magnetic microsphere,aptamer,report DNA and ALP labeled anti-digoxin,were studied.The results showed that under the optimal conditions,the concentration of adenosine was linear to CL intensity in the range of 1.0 × 10-7-1.0 × 10-3 mol/L with a detection limit of 1.0 × 10-7 mol/L.The result showed that this method had a better specificity to adenosine than other nucleosides,and was capable of selectively detecting quantities of adenosine in a complex environment (serum).