Designed Synthesis of Dual Emitting Silicon Quantum Dot for Cell Imaging: Direct Labeling of Alpha 2-HS-Glycoprotein

Abstract

The innocent silicon quantum dots (SQDs) having dual emissive property (blue in VIS and red in NIR), high photostability, and freedom from auto fluorescence are designed and synthesized for the first time using ethylene glycol. A new attempt has been made for direct labeling of Alpha 2-HS-Glycoprotein (Fetuin A) through functionalization of the synthesized dots by EDC coupling. The SQDs were characterized by FTIR, TEM, AFM, XRD, EDX, DLS, and TGA. The chemistry involved in the synthesis and functionalization of dots is elucidated in detail. The synthesized SQDs are suitable for live cell imaging as well as direct labeling of the Fetuin A in the NIR region. The direct labeling technique developed for Fetuin A imaging is robust, more specific, and simple, and reduces the number of incubation and washing steps and produces better quality data compared to the conventional method using Rhodamine B.

Are Fluorescent Silicon Nanoparticles Formed in a One-Pot Aqueous Synthesis?

“…In 2013, a new aqueous synthetic approach based on one-pot synthesis of fluorescent Si NPs, using of (3-aminopropyl)­trimethoxysilane (APTMS) as the silicon source and trisodium citrate dihydrate (Na 3 Cit), was reported by Zhong et al This work has attracted a great deal of attention from the scientific community since 2013 and has accumulated 227 citations according to Google Scholar (June 6, 2019), 203 citations according to Scopus (May 18, 2019), and 191 citations according to SciFinder (June 6, 2019). Among all these papers, special attention should be paid to those that specifically mention use of the approach described in this paper for the basis of or jumping off point for their own work. − At first inspection, the proposed technique seems to have many advantages in comparison with most other approaches reported earlier. Of these advantages, one can emphasize in particular the following: (i) water is used as a solvent, (ii) short reaction times are sufficient (15 min), (iii) low temperatures are needed (160 °C), and (iv) inexpensive precursors work well.…”

Nitrogen‐rich silicon quantum dots: facile synthesis and application as a fluorescent ‘on–off–on’ probe for sensitive detection of Hg2+ and cyanide ions

“…In addition, a main absorption peak at 246 nm (5.05 eV) was observed, which could be assigned to the г–г direct band gap transition in the SiQD core. [ 37 ] The fluorescence emission peak of the NR‐SiQDs was observed at 450 nm after excitation at 350 nm (Figure 3b). As shown in Figure3(c), the emission wavelength of NR‐SiQDs was dependent on the excitation wavelength, which was similar to other SiQDs.…”

Influence of Thickness of Active Silicon Nanoparticle Films in Heterojunction Photodetectors

“…The other two significant humps at 300 and 360 nm were probably originated from the direct Γ-Γ transition of the particles. [23,24] This appreciable Γ component permits zero-phonon, quasi-direct optical transitions in the SiNPs. The mechanism of surface scattering-induced Γ-X coupling enhances the strength of quasi-direct, zero-phonon transitions.…”

“…The mechanism of surface scattering-induced Γ-X coupling enhances the strength of quasi-direct, zero-phonon transitions. [23,24] The space confinement in nanoparticles broadens the distribution of wavefunctions in k-space resulting in the enhancement of optical transition. This transition is forbidden in the case of bulk silicon by the momentum conservation law, whereas in the case of nanoparticles, the momentum conservation is relaxed due to the confinement effect as per Heisenberg's uncertainty principle.…”