Department of Mechanical Engineering, University of Akron, Akron, OH, 44325, United States.
Department of Biomedical Engineering, Pennsylvania State University, State College, PA, 16801, United States.
Biosens Bioelectron. 2022 May 1;203:114023. doi: 10.1016/j.bios.2022.114023. Epub 2022 Jan 23.
Detection of small biomolecules is critical for understanding molecular mechanisms in biological systems and performing in vitro diagnosis in clinics. Current antibody based detection methods face large challenges in detecting small biomolecules at low concentrations. We report a new method for detecting small biomolecules based on molecular recognition and nanoparticle (NP) counting. Aptamer-functionalized NPs are attached to complementary sequence (CS)-conjugated microparticle (MP) carriers. In the presence of target small biomolecules at ultra low concentrations, NPs would be released from the MP carriers. Coupled with a resistive pulse sensor (RPS) using a micropore that counts the released NPs, this method can measure the concentrations of target biomolecules at low concentrations with high sensitivity and high throughput. Adenosine was used as a model to demonstrate the feasibility of this method. It is demonstrated that this method can detect a wide range of adenosine concentrations with a low detection limit of 0.168 nM, which is 10 times lower than that of the ELISA kit. With its simple structure, high sensitivity, and high reproducibility, this detection method holds great potential for the ultrasensitive detection of low abundance small biomolecules.
检测小分子对于理解生物系统中的分子机制和进行临床体外诊断至关重要。目前基于抗体的检测方法在检测低浓度的小分子时面临着巨大的挑战。我们报告了一种基于分子识别和纳米粒子（NP）计数的新的小分子检测方法。适配体功能化的 NPs 与互补序列（CS）偶联的微粒子（MP）载体结合。在超低浓度的目标小分子存在下，NPs 将从 MP 载体上释放出来。与使用微孔的电阻脉冲传感器（RPS）相结合，该方法可以高灵敏度和高通量地测量低浓度目标生物分子的浓度。以腺苷作为模型，验证了该方法的可行性。结果表明，该方法可以检测广泛的腺苷浓度，检测限低至 0.168 nM，比 ELISA 试剂盒低 10 倍。该检测方法结构简单、灵敏度高、重现性好，在超灵敏检测低丰度小分子方面具有很大的潜力。
