Selenium and nitrogen co-doped carbon quantum dots as a fluorescent probe for perfluorooctanoic acid.

Highly fluorescent carbon quantum dots co-doped with selenium and nitrogen  (SeN-CQDs) were fabricated via a one-pot hydrothermal route using selenomethionine as the sole precursor. The SeN-CQDs aggregates have sizes between 30 and 45 nm and display blue fluorescence with a quantum yield of 8% at excitation/emission wavelengths of 350/445 nm. The fluorescence is pH dependent and decreases under acidic conditions.

Dual-emission of Eu based metal-organic frameworks hybrids with carbon dots for ratiometric fluorescent detection of Cr(VI).

A novel blue fluorescence nitrogen and cobalt(II) co-doped carbon dots (CDs) encapsulated in europium metal-organic frameworks (CDs@Eu-MOFs) were synthesized to form a ratiometric fluorescent sensor for the detection of Cr(VI). The CDs@Eu-MOFs were characterized by transmission electron microscopic (TEM), scanning electron microscopic (SEM), Fourier transform infrared (FT-IR) and X-ray powder diffraction (XRD) techniques. The as-prepared CDs@Eu-MOFs not only kept the fascinating optical properties of CDs and Eu to give dual-emission but also had good stability in an aqueous solution.

Green synthesis of carbon dots functionalized silver nanoparticles for the colorimetric detection of phoxim.

In this work, Lycii Fructus as raw materials for green synthesis of fluorescent carbon dots (CDs) reduce AgNO. The CDs-AgNPs were synthesized by one-step method. CDs were applied to stabilize AgNPs due to abundant functional groups on the surface of CDs.

Silver nanoparticles-based colorimetric array for the detection of Thiophanate-methyl.

A simple and selective colorimetric sensor based on citrate capped silver nanoparticles (Cit-AgNPs) is proposed for the detection of Thiophanate-methyl (TM) with high sensitivity and selectivity. The method based on the color change of Cit-AgNPs from yellow to cherry red with the addition of TM to Cit-AgNPs that caused a red-shift on the surface plasmon resonance (SPR) band from 394nm to 525nm due to the hydrogen-bonding and substitution. The density functional theory (DFT) method was also calculated the interactions between the TM and citrate ions.

Colorimetric recognition of 6-benzylaminopurine in environmental samples by using thioglycolic acid functionalized silver nanoparticles.

A simple and selective colorimetric sensor thioglycolic acid capped silver nanoparticles (TGA-AgNPs) was developed for the detection of 6-benzylaminopurine (6-BAP). The synthesized TGA-AgNPs were characterized by UV-vis spectroscopy, dynamic light scattering (DLS), and transmission electron microscopic (TEM) techniques. The TGA-AgNPs as a sensor for binding 6-BAP through hydrogen-bonding and π-π bonding that causes large conjugate clusters, resulting in a color change from yellow to reddish orange.

Green synthesis of carbon dots originated from Lycii Fructus for effective fluorescent sensing of ferric ion and multicolor cell imaging.

Green, economical and effective method was developed for synthesis of fluorescent carbon dots (CDs), using one-pot hydrothermal treatment of Lycii Fructus. Optical and structural properties of the CDs have been extensively studied by UV-visible and fluorescence spectroscopic, x-ray diffraction (XRD) techniques, transmission electron microscopy (TEM) and high resolution TEM (HRTEM). Surface functionality and composition of CDs has been illustrated by Fourier transform infrared spectroscopy (FTIR), x-ray photoelectron spectroscopy (XPS) spectra and elemental analysis.

Reversible Fluorescence Probe Based on N-Doped Carbon Dots for the Determination of Mercury Ion and Glutathione in Waters and Living Cells.

An "on-off-on" mode was developed for the detection of mercury ion (Hg) and glutathione (GSH) with high sensitivity and selectivity based on the nitrogen-doped carbon dots (N-CDs) fluorescent probe. The N-CDs were synthesized through microwave treatment of citric acid and diethylenetriamine for 2 min, and exhibited excellent fluorescence properties and high quantum yield (27.7%).