Sulfonic acid functionalized zirconium-based metal–organic framework for the selective detection of copper(ii) ions

A sulphonic acid functionalized Zr(iv) MOF probe was used for the rapid, sensitive and selective sensing of Cu2+.

Cu2+-Regulated reversible coordination interaction of GQD@Tb/GMP ICP nanoparticles: towards directly monitoring cerebrospinal acetylcholinesterase as a biomarker for cholinic brain dysfunction

This work demonstrates a new strategy for sensing cerebrospinal acetylcholinesterase (AChE) as a cholinergic biomarker for brain dysfunction based on graphene quantum dot (GQD)-functionalized lanthanide infinite coordination polymer (Ln-ICP) nanoparticles. The ICPs used in this work were comprised of two components, i.e. a supramolecular Ln-ICP host formed by the coordination between the GMP ligand and central metal ion Tb3+, and guest GQDs with abundant functional groups, which were utilized as antenna ligands to further sensitize the fluorescence of Tb/GMP. Upon excitation at 300 nm, the obtained GQD@Tb/GMP ICP nanoparticles exhibited enhanced green fluorescence from Tb/GMP. With the addition of Cu2+, the competitive coordination between Cu2+ and GQDs weakened the antenna effect, leading to a decrease in the fluorescence of GQD@Tb/GMP ICPs. However, in the presence of thiocholine (TCh), a thiol-containing compound hydrolyzed from acetylthiocholine (ATCh) by AChE, a stronger coordination interaction between Cu2+ and TCh occurred, resulting in the restoration of the fluorescence of GQD@Tb/GMP ICPs. Using the method established herein, the cerebrospinal AChE fluctuation of rats with acute organophosphorus pesticide (OP) poisoning or chronic Alzheimer's disease (AD) could be monitored. This study essentially provides a novel approach to realize the direct monitoring of a biomarker for brain dysfunction by regulating the competitive coordination interaction reversibly, which is critical in the early diagnosis and therapy of brain diseases.

Fullerol Nanocatalysis and Trimodal Surface Plasmon Resonance for the Determination of Isocarbophos

Fullerol (C₆₀OH) has been shown to catalyze the trisodium citrate (TSC)-silver nitrate reaction to generate Ag nanoparticles (AgNPs). These AgNPs exhibit significant nanoplasmic surface-enhanced Raman scattering (SERS), resonance Rayleigh scattering (RRS), and absorption (Abs). When an aptamer (Apt) adsorbs on the C₆₀OH surface, catalysis is inhibited, and the intensities of SERS, RRS, and Abs decrease. In the presence of isocarbophos (IPS), Apt forms a stable complex (Apt-IPS) and releases C₆₀OH. As a result, SERS, RRS, and Abs intensities increase with increasing IPS concentration. Accordingly, a new SERS, RRS, and Abs trimodal method using Apt-labeled fullerol was established for the determination of IPS. Of the three spectral methods, SERS was the most sensitive, while the Abs method was the most cost-effective.

Functional Carbon Quantum Dots: A Versatile Platform for Chemosensing and Biosensing

Carbon quantum dot has emerged as a new promising fluorescent nanomaterial due to its excellent optical properties, outstanding biocompatibility and accessible fabrication methods, and has shown huge application perspective in a variety of areas, especially in chemosensing and biosensing applications. In this personal account, we give a brief overview of carbon quantum dots from its origin and preparation methods, present some advance on fluorescence origin of carbon quantum dots, and focus on development of chemosensors and biosensors based on functional carbon quantum dots. Comprehensive advances on functional carbon quantum dots as a versatile platform for sensing from our group are included and summarized as well as some typical examples from the other groups. The biosensing applications of functional carbon quantum dots are highlighted from selective assays of enzyme activity to fluorescent identification of cancer cells and bacteria.