An Artificial Tongue Fluorescent Sensor Array for Identification and Quantitation of Various Heavy Metal Ions

Herein, a small-molecule fluorescent sensor array for rapid identification of seven heavy metal ions was designed and synthesized, with its sensing mechanism mimicking that of a tongue. The photoinduced electron transfer and intramolecular charge transfer mechanism result in combinatorial interactions between sensor array and heavy metal ions, which lead to diversified fluorescence wavelength shifts and emission intensity changes. Upon principle component analysis (PCA), this result renders clear identification of each heavy metal ion on a 3D spatial dispersion graph. Further exploration provides a concentration-dependent pattern, allowing both qualitative and quantitative measurements of heavy metal ions. On the basis of this information, a “safe-zone” concept was proposed, which provides rapid exclusion of versatile hazardous species from clean water samples based on toxicity characteristic leaching procedure standards. This type of small-molecule fluorescent sensor array could open a new avenue for multiple heavy metal ion detection and simplified water quality analysis

High-Efficiency in Vitro and in Vivo Detection of Zn²⁺ by Dye-Assembled Upconversion Nanoparticles

Development of highly sensitive and selective sensing systems of divalent zinc ion (Zn²⁺) in organisms has been a growing interest in the past decades owing to its pivotal role in cellular metabolism, apoptosis, and neurotransmission. Herein, we report the rational design and synthesis of a Zn²⁺ fluorescent-based probe by assembling lanthanide-doped upconversion nanoparticles (UCNPs) with chromophores. Specifically, upconversion luminescence (UCL) can be effectively quenched by the chromophores on the surface of nanoparticles via a fluorescence resonant energy transfer (FRET) process and subsequently recovered upon the addition of Zn²⁺, thus allowing for quantitative monitoring of Zn²⁺. Importantly, the sensing system enables detection of Zn²⁺ in real biological samples. We demonstrate that this chromophore–UCNP nanosystem is capable of implementing an efficient in vitro and in vivo detection of Zn²⁺ in mouse brain slice with Alzheimer’s disease and zebrafish, respectively

High-Efficiency in Vitro and in Vivo Detection of Zn²⁺ by Dye-Assembled Upconversion Nanoparticles

Development of highly sensitive and selective sensing systems of divalent zinc ion (Zn²⁺) in organisms has been a growing interest in the past decades owing to its pivotal role in cellular metabolism, apoptosis, and neurotransmission. Herein, we report the rational design and synthesis of a Zn²⁺ fluorescent-based probe by assembling lanthanide-doped upconversion nanoparticles (UCNPs) with chromophores. Specifically, upconversion luminescence (UCL) can be effectively quenched by the chromophores on the surface of nanoparticles via a fluorescence resonant energy transfer (FRET) process and subsequently recovered upon the addition of Zn²⁺, thus allowing for quantitative monitoring of Zn²⁺. Importantly, the sensing system enables detection of Zn²⁺ in real biological samples. We demonstrate that this chromophore–UCNP nanosystem is capable of implementing an efficient in vitro and in vivo detection of Zn²⁺ in mouse brain slice with Alzheimer’s disease and zebrafish, respectively