Biosensors Based on Graphene Oxide Functionalized with Benzothiadiazole-Derived Ligands for the Detection of Cholesterol

Abstract

In this work, imidazole-or imidazolium-based benzothiadiazole ligands functionalized on graphene oxide combined with cholesterol oxidase constitute efficient, robust, and easy-to-handle materials with high biosensing activity for the detection of cholesterol by colorimetric methods. The presence of lanthanum(III) supported on graphene oxide as a possible coordinating site for the benzothiadiazole ligands was also evaluated, and its bioactivity was compared to that of the analogous material without the rare-earth metal. Our results demonstrated that graphene oxide functionalized with 4,7-bis-(imidazol-1-yl)-2,1,3-benzothiadiazole exhibited the best performance for the quantification of total cholesterol with a sensitivity of 0.0649 (with lanthanum) and 0.0618 au dL mg −1 (without lanthanum). In addition, these materials presented a better percentage of immobilization (>90%), recovered activity, resistance to storage, and detection range than materials containing 4,7-[1-carboxymethyl-(imidazol-3-ium)]-2,1,3-benzothiadiazole chloride. Therefore, the combination of GO-BTD (Im/Ac)/ChOx (with or without lanthanum) affords efficient biosensors for the colorimetric detection of cholesterol.

Recent Uses of Ionic Liquids in the Recovery and Utilization of Rare Earth Elements

“…Lanthanum doped-graphene oxide functionalized with imidazole-or imidazolium-based benzothiadiazole ligands were use as fluorescent biosensors to the detection of cholesterol by colorimetric procedures [68]; for the above task, ChOx (cholesteroloxidase) enzyme was immobilize onto the various materials. Results showed that not all the compositions performed equally, summarizing Table 12 the limiting detections yielded by some of these derivatives.…”

Photoactive benzothiadiazole-N-heterocycle derivatives: synthesis, photophysics and water sensing in organic solvents

“…In 2019, Liu and coworkers reported a pyrazole-BTD conjugate that was used for the detection of Cu( ii ) and hydroxide by fluorescence spectroscopy. 38,39 Recently, Scholten and coworkers reported that ionic BTD-imidazole derivatives were efficient biosensors for cholesterol detection 40 while Neto and coworkers described pyridine-BTD derivatives that were applied as plasma membrane fluorescent markers. 41 On the other hand, different BTD-amine derivatives have been developed for uses as semiconductors for solar cells, 42 red-fluorescent emitters, 43 and charge-transport emitters for OLED technology.…”