Chemistry Department, Sharif University of Technology, Tehran, 11155-9516, Iran.
Nanoscale. 2018 Feb 1;10(5):2492-2502. doi: 10.1039/c7nr05801b.
In the present study, a ratiometric fluorescent sensor array as an artificial tongue has been developed on a nanopaper platform for chemical discrimination applications. The bacterial cellulose (BC) nanopaper was utilized for the first time as a novel, flexible, and transparent substrate in the optical sensor arrays for developing high-performance artificial tongues. To fabricate this platform, the hydrophobic walls on the BC nanopaper substrates were successfully created using a laser printing technology. In addition, we have used the interesting photoluminescence (PL) properties of an immobilized ratiometric probe (carbon dot-Rhodamine B (CD-RhB) nanohybrids) on the nanopaper platform to improve the visual discrimination analysis. Heavy metal ions were utilized as model analytes to verify the applicability of the fabricated nanopaper-based ratiometric fluorescent sensor array (NRFSA). Using the color variation of the NRFSA platform upon the addition of heavy metal ions, which have been obtained by a smartphone (under an UV irradiation), five heavy metal ions (i.e., Hg(ii), Pb(ii), Cd(ii), Fe(iii), and Cu(ii)) have been well-distinguished through the RGB analysis via production of the characteristic PL fingerprint-like response patterns for each of them. Moreover, the developed optical sensor array was successfully exploited to identify the heavy metal ions in the water and fish samples. We have also found that the PL spectra, which have been obtained by a spectrofluorometer, of the developed NRFSA can be exploited for discrimination applications. We believe that the nanopaper-based artificial tongues will provide innovative insights into the development of optical sensor arrays towards advanced (bio)chemical discrimination applications and can revolutionize the conventional optical sensor array technology.
在本研究中，我们开发了一种基于纳米纸平台的比率荧光传感器阵列作为人工舌头，用于化学鉴别应用。细菌纤维素 (BC) 纳米纸首次被用作光学传感器阵列中的新型灵活透明基底，用于开发高性能人工舌头。为了制造这个平台，我们成功地使用激光打印技术在 BC 纳米纸基底上创建了疏水性壁。此外，我们利用固定化比率探针（碳点-罗丹明 B (CD-RhB) 纳米杂化物）在纳米纸上的有趣光致发光 (PL) 特性来提高可视化判别分析。我们使用重金属离子作为模型分析物来验证所制造的基于纳米纸的比率荧光传感器阵列 (NRFSA) 的适用性。通过智能手机（在 UV 照射下）获得的 NRFSA 平台在添加重金属离子后颜色的变化，通过对每种离子产生特征 PL 指纹响应模式的 RGB 分析，可以很好地区分五种重金属离子（即 Hg(ii)、Pb(ii)、Cd(ii)、Fe(iii) 和 Cu(ii)）。此外，我们还成功地利用开发的光学传感器阵列来识别水样和鱼样中的重金属离子。我们还发现，通过分光荧光计获得的开发的 NRFSA 的 PL 光谱可用于鉴别应用。我们相信，基于纳米纸的人工舌头将为光学传感器阵列在先进（生物）化学鉴别应用方面的发展提供创新思路，并可能彻底改变传统的光学传感器阵列技术。
