Flower-like Gold Nanoparticles for In Situ Tailoring Luminescent Molecules for Synergistic Enhanced Chemiluminescence

In recent years, gold nanoparticles (AuNPs) have attracted much attention due to their ease of surface modification, excellent biocompatibility, and extraordinary optoelectronic and catalytic activities. Herein, based on a AuNP-catalyzed reaction, a strategy for tailoring luminescent molecules in situ is proposed to trigger an ultrastrong chemiluminescence (CL). In the strategy, flower-like AuNPs are prepared using CL molecular probes (Probe-OH for NaClO/ONOO^-) via one-pot synthesis and subsequently act as a tailor for Probe-OH to generate novel CL molecules, allowing a synergistic CL enhancement about 4 times that of initial Probe-OH. Furthermore, by modification with poly(vinylpyrrolidone) (PVP) on the surface, the CL signals (only for NaClO) are amplified by 100 times based on an intermolecular chemically initiated electron exchange luminescence (CIEEL) mechanism. Given the improved sensitivity and selectivity over Probe-OH, the thus-formed CIEEL nanoplatform (PVP-Au) is successfully developed for detecting NaClO in a wide range of 2.5-100 μM, and the detection limit is 10.68 nM. This work provides unprecedented perspectives for expanding this facile and effective strategy for CL amplification based on AuNP catalysis.

A General Route for Chemiluminescence of n-Type Au Nanocrystals

The photoluminescence, electroluminescence, and electrochemiluminescence from nanocrystals (NCs) have been extensively exploited for both fundamental and applied investigation over two decades, while the understanding of chemiluminescence (CL) from NCs is still far from clear by now. Herein, a general route for triggering CL from NC luminophore is proposed by extensively exploiting the charge transfer between n-type NCs and oxidants. Oxidants, such as K₂S₂O₈, H₂O₂, KMnO₄, and NaClO, can chemically inject the hole onto the valence band (VB) of methionine-capped n-type AuNCs (Met@AuNCs) and enable the occurrence of efficient radiative-charge-recombination between the chemically injected exogenous VB hole and the pre-existed endogenous conduction band (CB) electron, which eventually results in single-color and defect-involved CL with the maximum emission wavelength around 824 nm. The CL of Met@AuNCs/oxidant is qualified for ultrasensitive CL immunoassay in a similar procedure to the biotin-avidin and magnetic separation involved commercial CL immunoassay and exhibits acceptable performance for linearly determining carcinoembryonic antigen from 50 pg/mL to 100 ng/mL with a limit of detection of 10 pg/mL (S/N = 3). This strategy provides a general route to develop nanoparticulate CL luminophores and might eventually enable CL multiplexing assay via extensively exploiting the CL of different wavebands.

Europium functionalized black phosphorus quantum dots as a CRET platform for synergistically enhanced chemiluminescence

In this work, we synthesize stable europium ion modified black phosphorus quantum dots (Eu-BPQDs) using a microwave irradiation technique, which can react with organic amines exhibiting unique chemiluminescence (CL). The mechanism of the Eu-BPQDs/organic amines CL system accounting for the efficient CRET is induced by the chelation of organic amines with the surface functionalized europium.

Direct and Indirect Chemiluminescence: Reactions, Mechanisms and Challenges

Emission of light by matter can occur through a variety of mechanisms. When it results from an electronically excited state of a species produced by a chemical reaction, it is called chemiluminescence (CL). The phenomenon can take place both in natural and artificial chemical systems and it has been utilized in a variety of applications. In this review, we aim to revisit some of the latest CL applications based on direct and indirect production modes. The characteristics of the chemical reactions and the underpinning CL mechanisms are thoroughly discussed in view of studies from the very recent bibliography. Different methodologies aiming at higher CL efficiencies are summarized and presented in detail, including CL type and scaffolds used in each study. The CL role in the development of efficient therapeutic platforms is also discussed in relation to the Reactive Oxygen Species (ROS) and singlet oxygen (1O2) produced, as final products. Moreover, recent research results from our team are included regarding the behavior of commonly used photosensitizers upon chemical activation under CL conditions. The CL prospects in imaging, biomimetic organic and radical chemistry, and therapeutics are critically presented in respect to the persisting challenges and limitations of the existing strategies to date.

One-component nano-metal-organic frameworks with superior multienzyme-mimic activities for 1,4-dihydropyridine metabolism

Although a number of nanozymes have been developed, it is still difficult to develop single-component nanozyme with overall high multienzyme-like activities. In this study, the nanosized metal-organic frameworks (nano-MOFs) FePCN (PCN stands for porous coordination network) was synthesized by integrating zirconium and iron ions with different catalytic property on single-component MOFs and exhibited superior intrinsic multienzyme-like activities, namely oxidase-, peroxidase- and phosphatase-mimicking activity. The catalytic active sites of oxidase- and peroxidase-, and phosphatase-like activity of FePCN were Fe-centers and Zr-O clusters, respectively. Based on the intrinsic oxidase-like activity and the similarity of molecular structures between cytochrome P450 oxidase (CYP) cofactors and the organic linker in FePCN, FePCN exhibited high CYP-like activity to catalyze the oxidation of hypotensive drug 1,4-dihydropyridine (1,4-DHP) into diethyl 2,6-dimethylpyridine-3,5-dicarboxylate (DDPD) and the yield of DDPD reached over 80%. Moreover, as peroxidase- and phosphatase-mimics, FePCN was successfully applied to detecting H₂O₂ under neutral condition and catalyzing the dephosphorylation of adenosine triphosphate (ATP), respectively. This study provides a feasible way for rational design one-component nanomaterials as multienzyme-mimics.