Unexpected Fluorescence of Polyols and PEGylated Nanoparticles Derived from Carbon Dot Formation

Abstract

Synthesis of nanoparticles in high‐boiling alcohols (so‐called polyol synthesis) and surface functionalization of nanoparticles with polyethylene glycol (so‐called PEGylation) in combination with certain heating are often accompanied with an intense fluorescence in the blue to green spectral range. Based on the polyol synthesis of Zn3(PO4)2 nanoparticles and a critical consideration of the relevant experimental conditions—including the presence of nanoparticles, the role of dissolved metal salts (ZnCl2, MgCl2, KCl), the type of the polyol (DEG, GLY, PEG400), the temperature and time of heating (150–230 °C, 1–6 h)—we can correlate the observed fluorescence to the formation of carbon dots (C‐dots) stemming from thermal decomposition (i.e., dehydration and carbonization) of the polyol. Thus, the thermal decomposition of polyols results in C‐dots with a diameter of 3–5 nm at narrow size distribution. The formation of C‐dots is confirmed by transmission electron microscopy (TEM), high‐resolution TEM (HRTEM), X‐ray powder diffraction (XRD), Fourier‐transform infrared spectroscopy (FT‐IR), and fluorescence spectra.

A new mild, clean and highly efficient method for the preparation of graphene quantum dots without by-products

“…The peak located at 3431, 2918, 1646, 1426 and 1058 cm -1 corresponding to the signals of -OH, C=O, C=C, -COO and C-O groups of both GO and GQDs. [46][47][48][49] This indicates the similar oxygencontaining function groups of GO and GQDs and corresponding to the XPS results. CH stretching peak of C(=O)-H is located at 2553 cm -1 , the increased intensity of CH stretching peak in GQDs indicating the abundant C(=O)-H groups in GQDs.…”

“…This can be attributed to the passivation by periphery carboxylic groups. 48 As shown in Figure 3c, the GQD aqueous solution gives bright blue-green PL under UV-light (centre wavelength of UV-light is 365 nm). The Commission International d'Eclairage ( Figure S7) chromaticity coordinates for GQDs is (0.16, 0.21).…”

Simple and Efficient Synthesis of Strongly Green Fluorescent Carbon Dots with Upconversion Property for Direct Cell Imaging

“…Recently, fluorescent carbon dots (CDs) have attracted great attention in bioimaging and optoelectronic applications . The remarkable fluorescence property, low toxicity, and excellent water solubility of CDs make them ideal alternative material especially in biomedical field .…”

Tailoring Ca-Based Nanoparticles by Polyol Process for Use as Nematicidals and pH Adjusters in Agriculture

“…The mechanistic representation of the polyol process is still in the build, polyols participate in red/ox, complexation and decomposition reactions with the cations and anions of the solution and form intermediates before yielding nanoparticles. 26,27,[39][40][41][42][43][44][45][46] The products of the red/ox reactions are oxidized derivatives of polyols, like glycolaldehyde, glycoxylic acid, glycolic acid, oxalic acid, oxalates and CO2. Moreover, it has been shown by us and others that polyols of higher reductive ability and cations/anions of higher oxidizing activity react in situ with polyols favoring the oxidation pathway while increasing the effectiveness of polyols as carbon sources.…”

“…Moreover, it has been shown by us and others that polyols of higher reductive ability and cations/anions of higher oxidizing activity react in situ with polyols favoring the oxidation pathway while increasing the effectiveness of polyols as carbon sources. 26,27,39,41,[44][45][46]…”