Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
Adv Healthc Mater. 2014 Mar;3(3):412-23. doi: 10.1002/adhm.201300033. Epub 2013 Aug 21.
Patients with chest pain account for 10% of US emergency room visits according to data from the Center for Disease Control and Prevention (2013). For triage of these patients, cardiac biomarkers troponin I and T are endorsed as standard indicators for acute myocardial infarction (AMI, or heart attack). Thus, there is significant interest in developing a rapid, point-of-care (POC) device for troponin detection. In this work, a rapid, quantitative, and label-free assay, which is specific for cardiac troponin T (cTnT) detection, using fluorescent single-walled carbon nanotubes (SWCNTs), is demonstrated. Chitosan-wrapped carbon nanotubes are cross-linked to form a thin gel that is further functionalized with nitrilotriacetic acid (NTA) moieties. Upon chelation of Ni(2+) , the Ni(2+) -NTA group binds to a hexa-histidine-modified troponin antibody, which specifically recognizes the target protein, troponin T. As the troponin T binds to the antibody, the local environment of the sensor changes, allowing direct troponin detection through intensity changes in SWCNT bandgap fluorescence. This platform represents the first near-infrared SWCNT sensor array for cTnT detection. Detection can be completed within 5 min, demonstrating a linear response to cTnT concentration and an experimental detection limit of 100 ng mL(-1) (2.5 nm). This platform provides a promising new tool for POC AMI detection in the future. Moreover, the work presents two new methods of quantifying the number of amines and carboxylic groups, respectively, in a carbon hydrogel matrices.
根据疾病控制与预防中心（CDC）的数据，胸痛患者占美国急诊室就诊人数的 10%。对于这些患者的分诊，心肌标志物肌钙蛋白 I 和 T 被认为是急性心肌梗死（AMI，即心脏病发作）的标准指标。因此，人们非常有兴趣开发一种用于肌钙蛋白检测的快速、即时护理（POC）设备。在这项工作中，展示了一种使用荧光单壁碳纳米管（SWCNT）的快速、定量和无标记检测方法，该方法特异性检测心脏肌钙蛋白 T（cTnT）。壳聚糖包裹的碳纳米管交联形成薄凝胶，进一步用亚氨基三乙酸（NTA）部分功能化。在螯合 Ni(2+)后，Ni(2+)-NTA 基团与六组氨酸修饰的肌钙蛋白抗体结合，该抗体特异性识别靶蛋白肌钙蛋白 T。随着肌钙蛋白 T 与抗体结合，传感器的局部环境发生变化，通过 SWCNT 带隙荧光强度变化可以直接检测肌钙蛋白。该平台代表了用于 cTnT 检测的第一个近红外 SWCNT 传感器阵列。检测可以在 5 分钟内完成，显示出与 cTnT 浓度的线性响应，实验检测限为 100ng mL(-1)（2.5nm）。该平台为未来即时护理 AMI 检测提供了一种有前途的新工具。此外，这项工作分别提出了两种新的方法来定量计算碳水凝胶基质中的胺和羧酸基团的数量。
