Nanotechnology-Based Environmental Smart Sensors for Personal Health Exposure Monitoring

 描述（由申请人提供）：拟议研究的一个广泛目标是开发包括可穿戴无线传感器阵列的个人暴露监测器，以检测呼吸区内的有害空气污染物，并改善流行病学研究中致病性暴露-剂量-反应关系的评估。异质正交检测器包括功能化的碳纳米管（CNT）为基础的谐振器将被设计和集成与智能手机平台，目标是检测环境臭氧（O3）在第一阶段，颗粒物，NOx和VOC在第二阶段。臭氧不仅通过温室气体排放影响全球气候变化，而且通过交通和工业污染产生的前体，作为城市烟雾中的二次污染物，对人类健康产生不利影响。作为一种强大的氧化剂气体，O3一旦被吸入就会引起一系列生理反应，包括肺功能降低和气道发炎，加剧哮喘等呼吸道疾病。许多研究工作都致力于解决臭氧暴露与健康结果之间的关系，包括死亡率和发病率（住院治疗，肺功能下降和哮喘状态），但由于缺乏个人暴露数据，在评估剂量反应关系时可能会出现相当大的误差。目前，市场上没有适合于呼吸区内的真实的O3暴露测量的现有传感器。第一阶段研究开发了臭氧暴露检测器阵列，使用两类纳米传感器制造：（a）聚丁二烯聚合物功能化的CNT薄膜，（B）用Pt或Pd金属纳米颗粒装饰的CNT薄膜。两者都提供了最大的灵敏度臭氧，同时降低交叉敏感性的干扰，如氮氧化物。这些探测器薄膜集成了紧凑的射频（RF）谐振器，其响应与独特的谐振位移所造成的分子水平的气体吸附在膜界面上。与化敏电阻器相比，该RF纳米传感器中的振幅和频率偏移都可以用于最小化假阳性以用于鲁棒辨别。主传感器和参比传感器（纯CNT）之间的差分信号可以补偿湿度等环境因素，进一步提高选择性。差分信号通过微控制器与智能手机无线连接，用于浓度水平的数据显示和通过参与式和无处不在的传感与公共卫生专业人员或监管机构的数据通信。另外，嵌入在移动的电话中的传感器产生关于受试者的运动、身体活动、时间戳和GPS位置的信息，这些信息可以与暴露相关联。将开发原型O3传感器，并在受控实验室和环境条件下表征其性能。将对志愿人员进行实地测试，以检测环境臭氧作为几天时间的函数，并将结果与标准徽章采样器的测量结果直接进行比较。将与环境流行病学家合作，通过测量暴露后的eNO浓度来探索因果关系。

 DESCRIPTION (provided by applicant): A broad goal of the proposed research is to develop personal exposure monitors comprising wearable, wireless sensor arrays to detect harmful air pollutants within the breathing zone, and improve the assessment of causative exposure-dose-response relationships in epidemiological studies. Heterogeneous orthogonal detectors comprising functionalized carbon nanotube (CNT) based resonators will be designed and integrated with a smart phone platform, targeting the detection of ambient ozone (O3) in Phase 1, particulate matter, NOx and VOCs in Phase 2. Ozone not only influences climatic changes globally through greenhouse gas emissions, but also produces adverse health effects in humans as a secondary pollutant in urban smog through precursors generated in traffic and industrial pollution. As a powerful oxidant gas, O3 can elicit a range of physiological responses once inhaled, including reduced lung function and inflamed airways, exacerbating respiratory diseases such as asthma. Numerous research efforts address the relationship between ozone exposure and health outcomes including mortality and morbidity (hospitalizations, decrements in lung function, and asthma status), but due to lack of personal exposure data, considerable error may be introduced in assessing dose-response relationships. Currently, there are no existing sensors in the market suitable for real- time O3 exposure measurement within the breathing zone. Phase 1 research develops an ozone exposure detector array, fabricated using two classes of nanosensors: (a) polybutadiene polymer-functionalized CNT thin-films, (b) CNT thin-films decorated with Pt or Pd metallic nanoparticles. Both offer maximum sensitivity to ozone while reducing cross-sensitivity to interferents such as NOx. These detector films are integrated with compact radio-frequency (RF) resonators, which respond with unique resonance shift caused by molecular level gas adsorption on the film interface. In contrast to a chemiresistor, both amplitude and frequency shifts in this RF nanosensor may be used to minimize false positives for robust discrimination. Differential signaling between the primary sensor and a reference sensor (pure CNTs) compensates for environmental factors such as humidity, further improving selectivity. The differential signal is wirelessly interfaced through a microcontroller t a smart phone for data display of concentration levels and data communication to public health professionals or regulatory bodies via participatory and ubiquitous sensing. Additionally, sensors embedded in the mobile phone yield information on motion, physical activity, time stamp and GPS location of the subject that can be correlated to the exposure. A prototype O3 sensor will be developed and its performance characterized under controlled laboratory and ambient conditions. Field tests will be conducted on human volunteers to detect ambient ozone as a function of time over several days, and results compared directly with measurements made by standard badge samplers. Causative relationships will be explored by measuring eNO concentrations following the exposure, in collaboration with an environmental epidemiologist.