College of Chemistry and Pharmaceutical Sciences, Qingdao Agricultural University, Qingdao 266109, P. R. China.
Anal Chem. 2020 Mar 17;92(6):4592-4599. doi: 10.1021/acs.analchem.0c00018. Epub 2020 Mar 4.
Despite the recent developments on the construction of point-of-care testing (POCT) devices, it is still a big challenge to build portable POCT tools for simple, sensitive, selective, and quantitative determination of disease-related biomarkers. With this in mind, we developed a simple and user-friendly POCT tool for onsite analysis of DNA adenine methyltransferase (Dam) activity by using DNA tetrahedra-based hydrogel to trap glucose-producing enzymes for target recognition and signal transduction. The enzyme-encapsulated DNA hydrogel and the substrate of enzyme were separately modified on papers and then combined onto a commercial glucose test strip for the sensitive evaluation of Dam activity via using a personal glucose meter (PGM) for quantitative signal readout. Taking advantage of the great amount of enzyme entrapped in DNA hydrogel and the high signal amplification ability of enzyme, this POCT tool is capable of highly sensitive and selective determination of Dam activity with a direct detection limit down to 0.001 U/mL, which is superior to that of most previously reported biosensors. Furthermore, this device can also be applied to screen inhibitor and analyze Dam activity in spiked serum samples, indicating the great potential for clinical practice and diagnostic applications. Additionally, all the reactions for Dam assay are performed on paper, which is simple and deliverable to end-users for medical diagnostics at home or in-field.
尽管在即时检测（POCT）设备的构建方面取得了最新进展，但对于构建用于简单、灵敏、选择性和定量测定与疾病相关生物标志物的便携式 POCT 工具仍然是一个巨大的挑战。考虑到这一点，我们开发了一种简单易用的 POCT 工具，用于通过基于 DNA 四面体的水凝胶现场分析 DNA 腺嘌呤甲基转移酶（Dam）活性，该水凝胶用于捕获产葡萄糖的酶以进行靶标识别和信号转导。酶包封的 DNA 水凝胶和酶的底物分别修饰在纸上，然后组合到商业葡萄糖测试条上，通过个人血糖仪（PGM）进行定量信号读取，以灵敏地评估 Dam 活性。利用 DNA 水凝胶中大量的酶和酶的高信号放大能力，该 POCT 工具能够高度灵敏和选择性地测定 Dam 活性，其直接检测限低至 0.001 U/mL，优于大多数先前报道的生物传感器。此外，该设备还可用于筛选抑制剂并分析加标血清样本中的 Dam 活性，表明其在临床实践和诊断应用方面具有巨大的潜力。此外，Dam 测定的所有反应都在纸上进行，对于家庭或现场的医疗诊断，这种简单易用的方法可交付给终端用户。
