Ningbo Materials Science and Technology Institute , Chinese Academy of Sciences , Ningbo , 315201 , P. R. China.
The State Key Laboratory of Bielectronics , Sountheast University , Nanjing , 210096 , P. R. China.
ACS Sens. 2019 Apr 26;4(4):1081-1089. doi: 10.1021/acssensors.9b00289. Epub 2019 Apr 5.
Breath analysis has been considered a noninvasive, safe, and reliable way to diagnose cancer at very early stage. Rapid detection of cancer volatile markers in breath samples via a portable sensing device will lay the foundation of future early cancer diagnosis. Nevertheless, unsatisfactory sensitivity and specificity of these sensing devices restrain the clinical application of breath analysis. Herein, we proposed the strategy of designing the light-regulated electrochemical reaction assisted core-shell heterostructure to address the issue of concern; that is, the photoactive shell will be designed for trigging the light-regulated electrochemical reaction and enhancing the sensitivity while a catalytic active core will play the function of removing interference gases. After screening of various core candidates, FeO was found to exhibit relatively low conversion rate to 3-methylhexane, which is one of the representative volatile markers for breath analysis, suggesting that mutual interference would be eliminated by FeO. Based on this assumption, an electrochemical sensor comprising core-shell FeO@ZnO-SE (vs Mn-based RE) was fabricated and sensing properties to 6 kinds of volatile markers was evaluated. Interestingly, the thickness of ZnO shell significantly influenced the response behavior; typically, the FeO@ZnO with shell thickness of 4.8 nm offers the sensor high selectivity to 3-methylhexane. In contrast, significantly mutual response interference is observed for the FeO@ZnO with extremely thick/thin shell. Particularly, sensing properties are greatly enhanced upon illumination; a detection limit to 3-methylhexane can even be as low as 0.072 ppm which will be useful in clinic application. Besides, the high selectivity of the sensor to 3-methylhexane is further confirmed by the testing of simulated breath samples. In summary, we anticipate that the strategy proposed in this research will be a starting point for artificially tailoring the sensitivity and selectivity of future sensing devices.
呼吸分析被认为是一种非侵入性、安全和可靠的方法，可以在早期阶段诊断癌症。通过便携式传感设备快速检测呼吸样本中的癌症挥发性标志物，将为未来的早期癌症诊断奠定基础。然而，这些传感设备的不理想的灵敏度和特异性限制了呼吸分析的临床应用。在此，我们提出了设计光调控电化学反应辅助的核壳异质结构的策略来解决这一问题；即，光活性壳将被设计用于触发光调控电化学反应并提高灵敏度，而催化活性核将发挥去除干扰气体的功能。在筛选了各种核候选物之后，发现 FeO 对 3-甲基己烷的转化率相对较低，3-甲基己烷是呼吸分析的代表性挥发性标志物之一，这表明 FeO 可以消除相互干扰。基于这一假设，制备了一种包含核壳 FeO@ZnO-SE（与基于 Mn 的 RE 相比）的电化学传感器，并评估了该传感器对 6 种挥发性标志物的传感性能。有趣的是，ZnO 壳的厚度显著影响了响应行为；通常，具有 4.8nm 壳厚的 FeO@ZnO 为传感器提供了对 3-甲基己烷的高选择性。相比之下，具有极厚/薄壳的 FeO@ZnO 会观察到明显的相互响应干扰。特别是，光照下传感器的性能大大增强；对 3-甲基己烷的检测限甚至可以低至 0.072ppm，这将有助于临床应用。此外，传感器对 3-甲基己烷的高选择性通过模拟呼吸样本的测试进一步得到证实。总之，我们预计本研究提出的策略将成为人为调整未来传感设备的灵敏度和选择性的起点。
