Designed multifunctional ratiometric fluorescent probe for directly detecting fluoride ion/ dichromate and indirectly monitoring urea.

In this study, a colorimetric and fluorescent dual-mode probe based on water-dispersible silicon nanoparticles (SiNPs) was fabricated via a one-step hydrothermal method by using (3-aminopropyl)triethoxysilane (APTES) as the silicon source and ferulic acid as the reducing agent. The as-prepared SiNPs exhibited good thermostability, high salt-tolerance and excellent photo-stability properties. The blue-green fluorescence of the SiNPs could be rapidly and selectively quenched by emodin, and meanwhile the colorimetric response from the original pale yellow color to reddish brown was also visible to the naked eye. Based on the above phenomenon, the quantitative detection of emodin could be achieved through both fluorescence and colorimetric methods. In the fluorescence method, a good linear relationship was obtained in the range of 0.05 to 50 μM with a detection limit of 5.77 nM. In the colorimetric method, comparable sensitivity was also achieved with a detection limit of 9.28 nM. The proposed method was successfully applied to the detection of emodin in traditional Chinese herbs Polygonum cuspidatum and Rheum officinale. Moreover, a SiNP based dual-mode paper sensor was also developed for the visual detection of emodin according to the color change and fluorescence quenching, providing a convenient strategy for emodin sensing.

Novel water-dispersible silicon nanoparticles as a fluorescent and colorimetric dual-mode probe for emodin detection

A highly selective fluorescent sensor for chlortetracycline based on histidine-templated copper nanoclusters.

Circularly polarized luminescent inorganics arouses attentions due to scalable preparation and versatile chiral optoelectronic applications. Here, strong circularly polarized luminescence (CPL) activity has been developed from self‐assembled cellulose nanocrystals decorated with blue emitting silicon quantum dots (QDs). The electrostatic attraction promotes the successful incorporation of QDs into chiral template matrix to form homogeneous hybrid nanoarchitecture films. It is found that their circular dichroism behaviors are closely related to the photonic band gap (PBG) while the CPL behaviors are determined by the QDs and PBG simultaneously. Furthermore, the as‐prepared chiral composite thin films have been employed as an efficient circularly polarized light source for preparing enantioselective polymer, which can induce chirality and photopolymerization simultaneously. Such strong CPL activity in nanoarchitecture films is highly promising for future inorganic optoelectronics.

Circularly Polarized Light Source from Self‐Assembled Hybrid Nanoarchitecture

In this work, water-soluble fluorescent silicon nanoparticles (SiNPs) were prepared by one-pot hydrothermal method using 3-(2-aminoethylamino)propyldimethoxymethylsilane (AEAPDMMS) as a silicon source and amidol as a reducing agent. The prepared SiNPs showed bright green fluorescence, excellent stability against photobleaching, salt tolerance, temperature stability, and good water solubility. Due to the internal filtration effect (IFE), rutin could selectively quench the fluorescence of the SiNPs. Based on such phenomena, a highly sensitive fluorescence method was established for rutin detection. The linear range and limit of detection (LOD) were 0.05–400 μM and 15.2 nM, respectively. This method was successfully applied to detect rutin in the samples of rutin tablets, Sophora japonica, fry Sophora japonica, and S. japonica carbon with satisfactory recovery.

Water Soluble Silicon Nanoparticles as a Fluorescent Probe for Highly Sensitive Detection of Rutin

Chromium (Cr(vi)), a highly toxic metal-oxyanion which is carcinogenic and mutagenic to humans, is a severe environmental pollutant. Developing simple methods for sensitive and selective detection of Cr(vi) is of great significance. In this work, fluorescent silicon nanoparticles (SiNPs) with good water solubility were facilely synthesized via a one-step hydrothermal method by using (3-aminopropyl)triethoxysilane (APTES) as the silicon source and natural antioxidant quercetin as the reducing agent. The obtained SiNPs displayed good thermostability, salt-tolerance and photo-stability. The as-prepared SiNPs exhibited bright blue emission at 437 nm under excitation at 362 nm, allowing them to be developed as a fluorescent probe for detection of Cr2O72-. Significantly, the fluorescence of the SiNPs could be remarkably quenched by Cr2O72-via the internal filtering effect (IFE). Based on this phenomenon, a novel fluorescence method for detection of Cr2O72- was established. A good linear relationship was obtained from 0.5 to 100 μM with a limit of detection (based on 3 s/k, LOD) of 180 nM. The proposed fluorescence method was successfully applied to the detection of Cr2O72- in tap water. Moreover, a fluorescent filter paper sensor was developed for the visual detection of Cr2O72-, providing a valuable platform for Cr2O72- sensing in a convenient way.

Qiujuan Ma

Papers

One-pot synthesis of novel water-dispersible fluorescent silicon nanoparticles for selective Cr2O72- sensing.