Redox-Controlled Fluorescent Nanoswitch Based on Reversible Disulfide and Its Application in Butyrylcholinesterase Activity Assay

Abstract

Butyrylcholinesterase (BChE) mainly contributing to plasma cholinesterase activity is an important indicator for routinely diagnosing liver function and organophosphorus poisoning in clinical diagnosis, but its current assays are scarce and frequently suffer from some significant interference and instability. Herein, we report a redox-controlled fluorescence nanoswtich based on reversible disulfide bonds, and further develop a fluorometric assay of BChE via thiol-triggered disaggregation-induced emission. Thiol-functionalized carbon quantum dots (thiol-CQDs) with intense fluorescence is found to be responsive to hydrogen peroxide, and their redox reaction transforms thiol-CQDs to nonfluorescent thiol-CQD assembly. The thiols inverse this process by a thiol-exchange reaction to turn on the fluorescence. The fluorescence can be reversibly switched by the formation and breaking of disulfide bonds caused by external redox stimuli. The specific thiol-triggered disaggregation-induced emission enables us to assay BChE activity in a fluorescence turn-on and real-time way using butyrylthiocholine iodide as the substrate. As-established BChE assay achieves sufficient sensitivity for practical determination in human serum, and is capable of avoiding the interference from micromolar glutathione and discriminatively quantifying BChE from its sister enzyme acetylcholinesterase. The first design of reversible redox-controlled nanosiwtch based on disulfide expands the application of disulfide chemistry in sensing and clinical diagnostics, and this novel BChE assay enriches the detection methods for cholinesterase activity.

Nitrogen-doped carbon nanodots for bioimaging and delivery of paclitaxel

“…[5][6][7][8] Moreover, engineering the CND surface and exploiting the reactivity of functional groups for covalent or supramolecular interactions with functional molecules is a key to tune their properties and meet the requirements for specific tasks. [9][10][11][12][13][14][15][16][17][18][19] The synergistic integration of the component functionalities should enable the construction of nano-assemblies with superior and unique properties. [20][21][22][23][24][25][26] Considering the low toxicity nature, CNDs have opened new possibilities for biomedical purposes.…”

Highly fluorescent carbon dots as an efficient nanoprobe for detection of clomifene citrate

“…Carbon dots (CDs) represent a new category of 0 dimensional uorescent nanomaterials enriched with surface functionalities and structural defects. Since the rst discovery in 2004, 12 the last decade have witnessed the ourish of CDs in drug delivery, 13,14 bioimaging, [14][15][16] photocatalysis, 17 sensing, [18][19][20][21][22] photochemical energy storage 23 and light-emitting devices. 24 Compared with conventional uorescent organics and semiconductor quantum dots, CDs hold a series of merits including excellent photostability, tunable emission wavelength, good water-solubility, easy surface functionalization and low cytotoxicity.…”

Ethylenediamine mediated luminescence enhancement of pollutant derivatized carbon quantum dots for intracellular trinitrotoluene detection: soot to shine

“… 2 CQDs deliver large application potential in a variety of areas. CQDs, can further be explored for various applications in different fields especially in chemosensing 3 and biosensing applications, 4 including photocatalysis, 5 photovoltaic devices, 6 optoelectronics, 7 bioimaging, 8,9 biolabeling, 10 drug delivery, 11 metal ion and explosive sensing 12 etc.…”