Gold Nanorods (AuNRs) and Zeolitic Imidazolate Framework-8 (ZIF-8) Core–Shell Nanostructure-Based Electrochemical Sensor for Detecting Neurotransmitters

Abstract

The development of novel electrode materials for rapid and sensitive detection of neurotransmitters in the human body is of great significance for early disease diagnosis and personalized therapy. Herein, gold nanorod@zeolitic imidazolate framework-8 (AuNR@ZIF-8) core–shell nanostructures were prepared by controlled encapsulation of gold nanorods within a ZIF-8 assembly. The designed AuNR@ZIF-8 nanostructures have uniform morphology, good dispersion, a large specific surface area, and an average size of roughly 175 nm. Compared with individual ZIF-8 and AuNR-modified electrodes, the obtained core–shell-structured AuNR@ZIF-8 nanocomposite structure-modified electrode shows excellent electrocatalytic performance in the determination of dopamine (DA) and serotonin (ST). The designed AuNR@ZIF-8 exhibited a wide linear range of 0.1–50 μM and low detection limit (LOD, 0.03 μM, S/N = 3) for the determination of DA, as well as a linear range of 0.1–25 μM and low LOD (0.007 μM, S/N = 3) for monitoring ST. The improved performance is attributed to the synergistic effect of the high conductivity of AuNRs and multiple catalytic sites of ZIF-8. The good electroanalytical ability of AuNR@ZIF-8 for detection of DA and ST can provide a guide to efficiently and rapidly monitor other neurotransmitters and construct novel electrochemical sensors.

Tunable growth of a single high-density ZIF nanoshell on a gold nanoparticle isolated in an optical trap

“…1,2,8,27 PVP enhances affinity of the AuNP for coordination-polymer spheres through interactions between the pyrrolidone rings and the zinc atoms in the ZIF crystal. 28,29 The particle solution is then combined with the chosen ZIF components, such as 2-Mim and zinc nitrate salt (Zn(NO 3 ) 2 ), after which it is injected into a sealed microscope chamber and positioned at the focus of the optical trapping microscope objective. We rely on DF spectroscopy and optical trapping force signatures to reliably trap only single AuNPs, approximately 10 μm above the glass coverslip surface inside the chamber.…”

“…Gold nanoparticlemetal organic framework (AuNP@MOF) hybrid structures have gained popularity in recent years as surface-enhanced Raman spectroscopy (SERS) substrates, 1,2 drug delivery particles, 3,4 gas sequestration systems, [5][6][7] reaction catalysts, [8][9][10][11] and low limit of detection (LOD) sensors. [12][13][14][15] In order to push these technologies forward new high precision techniques for controlled growth and characterization of particle structures, optical properties, and physical properties are required. Many synthetic procedures for zeolitic imidazolate frameworks (ZIFs), a widely studied and highly stable class of MOFs, generally achieve crystal growth by heating a reaction mixture in ovens or water baths.…”

Recent advances in surface modified gold nanorods and their improved sensing performance

“…It is worthwhile mentioning that although this section describes a variety of sensing techniques using surface modification, this is not an exhaustive list. Other sensing techniques using surface modified AuNRs which will not be covered in this article include fluorescence-involved sensing, 83,84 chirality sensing, 85,86 electrochemical sensing, [87][88][89] etc. Colourimetric sensing, monitoring the colour change of a sensor when it encounters analytes of interest, is a classic approach to optical sensing.…”

Copper ion based metal–organic framework nanomaterials with roughness enhanced protein adhesion for high-efficiency hemoglobin separation

“…[28][29][30] Compared with traditional materials, MOFs could be precisely regulated at the molecular level to achieve highly specific enrichment through rationally selecting organic ligands and metal cations. 31,32 In view of these excellent properties of the MOFs, great interest has been aroused in protein separation. For example, Tan et al facilely fabricated novel MOF-derived polymer-mediated magnetic hollow nanocages through orientation stress contraction (PDA@F127/ZIF-67), and the porous nanocage selectively enriches BHb via magnetic isolation.…”