Gogoi Neelam, Agarwal Devesh S, Sehgal Aishwarya, Chowdhury Devasish, Sakhuja Rajeev
Material Nanochemistry Laboratory, Physical Sciences Division, Institute of Advanced Study in Science and Technology, Garchuk, Guwahati 781035, Assam, India.
Department of Chemistry, Birla Institute of Technology & Science, Pilani, Rajasthan 333031, India.
ACS Omega. 2017 Jul 31;2(7):3816-3827. doi: 10.1021/acsomega.7b00643. Epub 2017 Jul 24.
Addressing the limitations associated with the detection of cholesterol, we present a one-pot synthesis of a carbon nanodot (CD) in an organic medium (CD) from a novel bile acid hydrazone-based organogel. Interestingly, CD possesses the aggregation-induced emission enhancement (AIEE) phenomenon, which rationally aids in the "enzyme-free" detection of cholesterol through a fluorescence turn-on mechanism. On dilution of the THF/water mixture of CD with its poor solvent (water), a 9.8-fold enhancement in its photoluminescence (PL) emission is witnessed. Such an enhancement in PL emission is credited to the occurrence of molecular restrictions due to the formation of nanoaggregates of CD, thereby initiating a radiative pathway for exciton decay. Excitingly on adding cholesterol to CD, we observed a similar enhancement in its PL emission without the use of any cholesterol oxidase (ChO ) enzyme. The limit of detection and limit of quantification of cholesterol is found to be as low as 1.09 and 3.64 μM, respectively. Hence, this contribution highlights the enzyme-free fluorescence turn-on detection of cholesterol by a novel CD rationally designed to extend its applicability in an organic medium, where it is still considered a major restraint.
针对与胆固醇检测相关的局限性，我们展示了一种在有机介质中由新型基于胆汁酸腙的有机凝胶一锅法合成碳纳米点（CD）。有趣的是，CD具有聚集诱导发光增强（AIEE）现象，这通过荧光开启机制合理地有助于“无酶”检测胆固醇。用其不良溶剂（水）稀释CD的四氢呋喃/水混合物时，其光致发光（PL）发射增强了9.8倍。PL发射的这种增强归因于由于CD纳米聚集体的形成而出现的分子限制，从而启动了激子衰变的辐射途径。令人兴奋的是，在向CD中添加胆固醇时，我们观察到其PL发射有类似的增强，而无需使用任何胆固醇氧化酶（ChO）。发现胆固醇的检测限和定量限分别低至1.09和3.64 μM。因此，这一贡献突出了一种新型CD对胆固醇的无酶荧光开启检测，该CD经过合理设计以扩展其在有机介质中的适用性，而在有机介质中这仍然被认为是一个主要限制。
