Najafabadi Marzieh Enteshari, Khayamian Taghi, Hashemian Zahra
Department of Chemistry, Isfahan University of Technology, Isfahan, Iran.
Department of Chemistry, Isfahan University of Technology, Isfahan, Iran.
J Pharm Biomed Anal. 2015 Mar 25;107:244-50. doi: 10.1016/j.jpba.2015.01.021. Epub 2015 Jan 15.
Magnetic nanoparticles (MNPs) conjugated with aptamer was developed for the selective extraction of adenosine in urine samples followed by electrospray ionization-ion mobility spectrometry (ESI-IMS). The ion mobility spectrum of adenosine showed two peaks at low concentrations and two more peaks related to dimer of adenosine at high concentrations. However, the ion mobility spectrum of eluent at low concentration showed only the peaks related to dimer of adenosine. In other words, aptamer captured two adenosine molecules between the top G-quartet and the two short stems, where they bonded to each other. The mass spectrum of the eluent also validated the presence of dimer (m/z 535.95). The effect of extraction parameters on extraction efficiency including sorbent amount, elution conditions (solvent type and volume) and adsorption conditions were investigated. Under the optimized conditions, the linear dynamic range was found to be 0.05-5.00 μg mL(-1) with detection limit of 0.02 μg mL(-1). The extraction efficiency was 94% and the relative standard deviation was 4% for three replicate measurements of adenosine at 0.25 μg mL(-1) in urine samples. As a practical application, the method was applied for the determination of adenosine in urine samples of patients with lung cancer, and the obtained results were in good agreement with those obtained by HPLC-UV method. Therefore, the proposed method is an alternative clinical analysis.
开发了与适体缀合的磁性纳米颗粒（MNPs），用于尿液样本中腺苷的选择性萃取，随后进行电喷雾电离-离子迁移谱（ESI-IMS）分析。腺苷的离子迁移谱在低浓度下显示两个峰，在高浓度下还有两个与腺苷二聚体相关的峰。然而，低浓度洗脱液的离子迁移谱仅显示与腺苷二聚体相关的峰。换句话说，适体在顶部G-四重体和两个短茎之间捕获了两个腺苷分子，它们在那里相互结合。洗脱液的质谱也证实了二聚体（m/z 535.95）的存在。研究了萃取参数对萃取效率的影响，包括吸附剂用量、洗脱条件（溶剂类型和体积）和吸附条件。在优化条件下，线性动态范围为0.05-5.00 μg mL(-1)，检测限为0.02 μg mL(-1)。对于尿液样本中0.25 μg mL(-1)的腺苷进行三次重复测量，萃取效率为94%，相对标准偏差为4%。作为实际应用，该方法用于肺癌患者尿液样本中腺苷的测定，所得结果与通过HPLC-UV法获得的结果高度一致。因此，所提出的方法是一种替代的临床分析方法。
