Nan Liu,Juan Hao,Keying Cai,Mulan Zeng,Zhenzhong Huang,Lili Chen,Bingxian Peng,Ping Li,Li Wang,Yonghai Song
A novel ratiometric fluorescence nanosensor for superoxide anion (O 2 •− ) detection was designed with gold nanoparticles-bovine serum albumin (AuNPs-BSA)@terbium/guanosine monophosphate disodium (Tb/GMP) nanoscale coordination polymers (NCPs) (AuNPs-BSA@Tb/GMP NCPs). The abundant hydroxyl and amino groups of AuNPs-BSA acted as binding points for the self-assembly of Tb 3+ and GMP to form core-shell AuNPs-BSA@Tb/GMP NCP nanosensors. The obtained probe exhibited the characteristic fluorescence emission of both AuNPs-BSA and Tb/GMP NCPs. The AuNPs-BSA not only acted as a template to accelerate the growth of Tb/GMP NCPs, but also could be used as the reference fluorescence for the detection of O 2 •− . The resulting AuNPs-BSA@Tb/GMP NCP ratiometric fluorescence nanosensor for the detection of O 2 •− demonstrated high sensitivity and selectivity with a wide linear response range (14 nM–10 μM) and a low detection limit (4.7 nM).
Li Yang,Yonghai Song,Mulan Zeng,Yue Du,Bingxian Peng,Zhenzhong Huang,Li Wang
It is of great significance for superoxide anion (O 2 •− ) detection due to its important role in regulation of biological function. The nanoscale coordination polymers (NCPs) core-shell nanostructures have attracted increasing interests for their nanosized-dependent properties. In this study, SiO 2 @Tb/guanosine 5′-monophosphate (GMP) NCPs with core-shell nanostructures was designed for O 2 •− detection. The SiO 2 @Tb/GMP NCPs core-shell nanostructures were produced by using SiO 2 nanoparticles (NPs) as template to control their nano-size. First, Tb 3+ was adsorbed on the surface of SiO 2 NPs by coordination with -COOH of SiO 2 NPs. Then the Tb/GMP NCPs shells were grown along the surface of SiO 2 NPs. The SiO 2 @Tb/GMP NCPs core-shell nanostructures were characterized with scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy and Zeta potential. The resulted SiO 2 @Tb/GMP NCPs core-shell nanostructures displayed strong Tb/GMP emission which decreased linearly with the increased O 2 •− concentration in the range from 5.3 nM to 6.0 μM with a limit detection of 2.18 nM. And the SiO 2 @Tb/GMP NCPs core-shell nanostructures also exhibited good selectivity and high sensitivity in HEPES buffer at pH 7.4.
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.
危险品化学品经营许可证（带存储）