Large-Scale Aqueous Synthesis of Fluorescent and Biocompatible Silicon Nanoparticles and Their Use as Highly Photostable Biological Probes

Abstract

A large-scale synthetic strategy is developed for facile one-pot aqueous synthesis of silicon nanoparticles (SiNPs) yielding ∼0.1 g SiNPs of small sizes (∼2.2 nm) in 10 min. The as-prepared SiNPs feature strong fluorescence (photoluminescence quantum yield of 20-25%), favorable biocompatibility, and robust photo- and pH-stability. Moreover, the SiNPs are naturally water dispersible, requiring no additional post-treatment. Such SiNPs can serve as highly photostable bioprobes and are superbly suitable for long-term immunofluorescent cellular imaging.

Ultra-small fluorescent inorganic nanoparticles for bioimaging

“…Furthering their research, the authors used (3-aminopropyl)trimethoxylsiliane as precursor and prepared 2.2 nm Si NPs by the similar method. 204 The obtained Si NPs exhibited strong green fluorescence with a QY of 20-25%, 15 biocompatibility, and robust photo-and pH-stability. As shown in Figure 22, FITC, CdTe and CdSe/ZnS QDs, and Si NPs exhibited distinct fluorescence behaviors during initial UV irradiation.…”

Optical Biosensing and Bioimaging With Porous Silicon and Silicon Quantum Dots (Invited Review)

“…The near infrared emission is particularly attractive as it allows penetration of biological tissues where scattering signals and absorption level is at minimal, a feature that is unachievable with visible emissions [107]. An emerging recent method of the top down method of preparing silicon quantum dots is fast modifications [108][109][110]. This comes as a need from two factors: the first being that silicon naturally oxidize and unmodified particles lose fluorescence over time, and the second most of these surface treatment methods are slow, represented by the hydrosilylation reaction approach [111].…”

“…This comes as a need from two factors: the first being that silicon naturally oxidize and unmodified particles lose fluorescence over time, and the second most of these surface treatment methods are slow, represented by the hydrosilylation reaction approach [111]. As can be see in Figure 7, silicon nanoparticles were prepared by first using etching to obtain silicon nanowires, then microwave is applied to facilitates attachment of hydrophilic proteins, which kept the red fluorescence from particles, and the procedures only took very short time to complete, which is highly desirable for imaging probes [108,112]. Another example was shown by the Veinot group which uses xenon difluoride which results in instantaneous attachment of surface molecules.…”

Interaction of polymer-coated silicon nanocrystals with lipid bilayers and surfactant interfaces

“…Silicon currently dominates the microelectronics industry but has achieved limited success in the realm of photonics, in part because of relatively poor bulk optical characteristics (e.g., weak photoluminescence, indirect bandgap). At the nanoscale, however, the emission characteristics of silicon are greatly enhanced by changes in band structure imposed by quantum confinement, and a variety of routes to hydrophilic colloidal silicon nanocrystals (SiNCs) have emerged in just the past few years [11][12][13][14][15][16][17][18][19][20][21]. Although many of these provide broad color access with bright emission and single-particle dispersion, polyethylene glycol (PEG) remains the coating of choice [22].…”