Engineering Quantum Dots with Ionic Liquid: A Multifunctional White Light Emitting Hydrogel for Enzyme Packaging

Abstract

Herein, a new and straightforward approach for the fabrication of a stable and multifunctional white light emitting (WLE) hydrogel is reported. For the first time, the utility of such hydrogels for protein packaging with enhanced activity and stability is presented. Initially, a WLE composite with color chromaticity of (0.33, 0.27) is fabricated by engineering the surface of an orange light emitting Mn2+‐doped ZnS quantum dot (QD) using a blue‐emitting choline‐tosylate ionic liquid (IL). The color chromaticity can be tuned by altering the concentration of the IL and excitation wavelengths. The WLE hydrogel is constructed through the conjugation of the WLE QD‐IL composite with an alginate biopolymer. Remarkably, the WLE QD‐IL composite and WLE hydrogel show preservation of their structural and luminescence properties for an extended time and thus indicate a potential for storage applications. When cytochrome c (Cyt C) is caged within the WLE hydrogel matrix, the peroxidase activity increases by more than 1.7‐times compared with native Cyt C and a Cyt C‐loaded QD hydrogel at room temperature. Also, Cyt C‐immobilized WLE hydrogel shows a 3.5‐fold increase in activity (compared with native Cyt C) at a higher temperature (120 °C) and in the presence of a denaturation agent.

Pseudohomogeneous metallic catalyst based on tungstate-decorated amphiphilic carbon quantum dots for selective oxidative scission of alkenes to aldehyde

“…It is noteworthy that the amide carbonyl stretching mode appears at 1680 cm −1 , C–O–C peak at 1215 cm −1 , the esteric C-O stretching at 1172 cm −1 , and C–O stretching vibrations at 1050 cm −1 18 . It can also be observed that there are bands in the range of about 1180 and 1384 cm −1 , which are due to the C–N stretching vibration and methylene group deformation vibrations from SA and [APMim][Cl] 19 , 20 . The bands at 2854, 2920 and 1452 cm −1 also reveal the symmetric, asymmetric stretching, and scissoring vibration modes from –CH 2 groups of these two moieties 21 .…”

The quantum dot-FRET-based detection of vitamin B12 at a picomolar level

“…[6][7][8][9][10][11][12][13][14][15][16] The details of the fabrication of ligand-free Mn 2+ -doped ZnS QDs and the technique of sensing of VB12 are described in the ESI. † 19 The as-fabricated Mn 2+ -doped ZnS QDs exhibited an absorption edge at 310 nm and an intense emission peak at 587 nm (due to the 4 T 1 -6 A 1 electronic transition of the Mn 2+ dopant ions present in the ZnS host) [17][18][19][20][21][22][23] at an excitation wavelength of 320 nm (Fig. 1A and B).…”

“…Environmentally sustainable metal-based QDs, especially Mn 2+ -doped ZnS QDs, have demonstrated their usefulness in bioimaging, white light generation, light emitting devices and optical sensing due to their long-wavelength atomic orange-red emission, photostable nature and lower toxicity. [17][18][19][20][21][22][23] For example, (i) white light generation could be possible from Mn 2+doped ZnS QDs followed by complexing their surface with two luminescent inorganic complexes, (ii) a reversible pH nanoprobe (in the physiological range 6.5-10.6) can be fabricated by complexing the surface of Mn 2+ -doped ZnS QDs with external chelating ligands, (iii) a white light emitting hydrogel, with the capability of enzyme packaging, could also be fabricated followed by engineering of the surface of Mn 2+ -doped ZnS QDs with ionic liquids. [19][20][21] Thus, the biocompatibility, ease of aqueous-based fabrication and lower toxicity of Mn 2+ -doped ZnS QDs make them a prime choice for the luminescence-based sensitive and selective detection of VB12.…”

“…[17][18][19][20][21][22][23] For example, (i) white light generation could be possible from Mn 2+doped ZnS QDs followed by complexing their surface with two luminescent inorganic complexes, (ii) a reversible pH nanoprobe (in the physiological range 6.5-10.6) can be fabricated by complexing the surface of Mn 2+ -doped ZnS QDs with external chelating ligands, (iii) a white light emitting hydrogel, with the capability of enzyme packaging, could also be fabricated followed by engineering of the surface of Mn 2+ -doped ZnS QDs with ionic liquids. [19][20][21] Thus, the biocompatibility, ease of aqueous-based fabrication and lower toxicity of Mn 2+ -doped ZnS QDs make them a prime choice for the luminescence-based sensitive and selective detection of VB12. Until now, there has been no report on the use of Mn 2+ -doped ZnS QDs as a nanoprobe for the detection of VB12.…”

“…It should be noted here that the optical emission of Mn 2+ -doped ZnS QDs is independent of their size and dependent on the population of Mn 2+ and surface passivation. [17][18][19][20][21][22][23] When the emission maxima were probed at 587 nm, the excitation spectrum of Mn 2+ -doped ZnS QDs appeared at around 320 nm (Fig. S1, ESI †).…”