Cucurbituril Enhanced Electrochemiluminescence of Gold Nanoclusters via Host–Guest Recognition for Sensitive D-Dimer Sensing

Abstract

Gold nanoclusters (AuNCs) are promising electrochemiluminescence (ECL) signal probes for their outstanding biocompatibility, unusual molecule-like structures, and versatile optical and electrochemical properties. Nevertheless, their relatively low ECL efficiency and poor stability in aqueous solutions hindered their application in the ECL sensing field. Herein, a facile host−guest recognition strategy was proposed to enhance the ECL efficiency and stability of Au NCs by rigidifying the surface of ligand-stabilized AuNCs via supramolecular self-assembly between cucurbiturils[7] (CB [7]) and L-phenylalanine (L-Phe). Meanwhile, mercaptopropionic acid (MPA) was introduced as a ligand in order to cooperatively enhance the performance of the AuNCs and facilitate the link between AuNCs and bioactive substances. The prepared CB[7]/L-Phe/MPA-AuNCs had a higher ECL emission efficiency, achieving about 2-fold stronger ECL intensity than that of L-Phe/MPA-AuNCs. In addition, after non-covalent modification with CB[7], the finite stability of the papered AuNCs was significantly improved. The prepared CB[7]/L-Phe/MPA-AuNCs showed excellent D-dimer sensing results, exhibiting a linear range from 50.00 fg/mL to 100.0 ng/mL and a detection limit of 29.20 fg/mL (S/N = 3). Our work demonstrated that the host−guest self-assembly strategy provided a universal approach for strengthening the ECL efficiency and stability of nanostructures on an ultra-small scale.

Signal-Enhanced Immunosensor-Based MOF-Derived ZrO2 Nanomaterials as Electrochemiluminescence Emitter for D-Dimer Detection

“…The DPV curve of the bare electrode displays a distinct oxidation peak at +0.772 V, whereas the oxidation peaks of the TiO 2 and TiO 2 –Cu modified electrodes were shifted to +0.760 and +0.752 V, respectively, accompanied by a significant increase in peak current values. This provided evidence that TiO 2 and TiO 2 –Cu can facilitate the oxidation of TPrA, generating more oxidant intermediate TPrA •+ . It was noteworthy that TiO 2 –Cu exhibited a stronger oxidation-promoting effect compared to TiO 2 .…”

“…The ECL efficiency of ZrO 2 and TiO 2 –Cu/ZrO 2 was typically evaluated using [Ru(bpy) 3 ] 2+ as a reference based on current methods . The relative ECL efficiency of luminophore was determined using the following relationship Φ normalE normalC normalL = Φ normalE normalC normalL 0 ( I Q normalf 0 / Q normalf I 0 ) Φ ECL 0 denoted the ECL efficiency value of 1 mmol/L [Ru(bpy) 3 ] 2+ under 0.1 mol/L TBAPF 6 /acetonitrile conditions, which was 5%.…”

“…This provided evidence that TiO 2 and TiO 2 − Cu can facilitate the oxidation of TPrA, generating more oxidant intermediate TPrA •+ . 43 It was noteworthy that TiO 2 − Cu exhibited a stronger oxidation-promoting effect compared to TiO 2 .…”

“…The ECL efficiency of ZrO 2 and TiO 2 −Cu/ZrO 2 was typically evaluated using [Ru(bpy) 3 ] 2+ as a reference based on current methods. 43 The relative ECL efficiency of luminophore was determined using the following relationship…”

Supramolecular Anchored Copper Nanoclusters for a Multipath Electrochemiluminescence Probe

“…Employing ethylenediamine as a ligand for Cu NCs holds promise in potentially mitigating the negative influences of oxidation and aggregation on the stability of the Cu NCs. Cucurbit[7]­uril is a fourth-generation macrocyclic host molecule with unique hydrophobic cavities and highly stable rigid outer shells, as well as molecular recognition and self-assembly properties. , Using host–guest identification of cucurbit[7]­uril to anchor novel supramolecular structures on the surface of Cu NCs could introduce a rigid barrier on the nanocluster surface and reduce nonradiative relaxation of the ligands . In addition, the introduced supermolecular structures can be used as “molecular vessels” to attract hydrophobic coreactant, such as tripropylamine (TPA) or triethylamine, thereby shortening the electron transfer distance between the coreactants and the luminescence center, thus improving the ECL performance of the Cu NCs.…”