Electroless Deposition of Palladium Nanoparticles on Graphdiyne Boosts Electrochemiluminescence

Abstract

Modulating the electronic structure of metal nanoparticles via metal−support interaction has attracted intense interest in the field of catalytic science. However, the roles of supporting substrates in regulating the catalytic properties of electrochemiluminescence (ECL) remain elusive. Here, we find that the use of graphdiyne (GDY) as the substrate for electroless deposition of Pd nanoparticles (Pd/GDY) produces the most pronounced anodic signal enhancement in luminol−dissolved oxygen (O 2 ) ECL system as co-reactant accelerator over other carbon-based Pd composite nanomaterials. Pd/GDY exhibits electrocatalytic activity for the reduction of O 2 through a four-electron pathway at approximately −0.059 V (vs Ag/AgCl) in neutral solution forming reactive oxygen species (ROS) as intermediates. The study shows that the interaction of Pd and GDY increases the amount and stability of ROS on the Pd/GDY electrode surface and promotes the reaction of ROS and luminol anion radical to generate excited luminol, which significantly boosts the luminol anodic ECL emission. Based on quenching of luminol ECL through the consumption of ROS by antioxidants, we develop a platform for the detection of intracellular antioxidants. This study provides an avenue for the development of efficient luminol ECL systems in neutral media and expands the biological application of ECL systems.

Boosting Electrochemiluminescence Performance of a Dual-Active Site Iron Single-Atom Catalyst-Based Luminol–Dissolved Oxygen System via Plasmon-Induced Hot Holes

“…This implies that in this study, the dominant formation of the O 2 •– and OH • radicals played a vital role in boosting the ECL signal of the luminol–DO system. Therefore, the plausible ECL mechanism is proposed for the luminol–DO system employing pFe-g-CN to serve as the CRA as presented in eqs – based on the experimental findings (Figure a). , At the initial stage, with anodic potential sweeping, DO in the sol is absorbed on the surface of pFe-g-CN and subsequently reduced into an oxygen radical (O 2 •– ), while at the same time, luminol is electrochemically oxidized into a luminol anion radical (L •– ) (eq ). After that, the two active species engage in a chemical reaction with the help of pFe-g-CN to produce the 3-aminophthalate anion (AP 2 2– *) as an excited-state intermediate (eq ), and finally, an impressive ECL emission is produced during the transition of the intermediate to the ground state (eq ).…”

Understanding Reactive Oxygen Species in Potential-Resolved Electrochemiluminescence of Luminol-Dissolved O2

“…The total amount of ROS generated under different potential ranges was estimated using fluorescence probe-2,7-dichlorodihydrofluorescein (DCDHF) . DCDHF could react with ROS and then be oxidized into dichlorofluorescein (DCF), which exhibited green fluorescence (λ em = 521 nm).…”

“…However, how these ROS influence the potential-resolved ECL pathways was unclear. Second, it is difficult to identify the multiple ROS and quantify their contributions in the ECL process due to their high reactivity and short life spans. , In addition, both the anodic and cathodic ECL of luminol-dissolved O 2 have been reported. − Nevertheless, most studies on the ECL enhancement of luminol-dissolved O 2 caused by ROS have focused on anodic ECL. , Therefore, a systematic study on the role of ROS in potential-dependent ECL of luminol-O 2 is necessary.…”

Regulating Reactive Oxygen Species over M–N–C Single-Atom Catalysts for Potential-Resolved Electrochemiluminescence

“…Luminol, a widely used luminophore, offers several advantages such as low excitation potential, low cost, and chemical stability. , As an ideal candidate of coreactant in the luminol ECL system, dissolved O 2 has attracted increasing attention depending on its biological compatibility compared to H 2 O 2 . In the luminol-dissolved O 2 system, coreaction accelerators have been extensively employed to promote the conversion of dissolved O 2 into various reactive oxygen species (ROS), such as hydroxyl radical (·OH) and superoxide radical (O 2 ·– ) to improve the luminescence efficiency of luminol. − It is worth noting that the 4-electron reduction pathway of O 2 can generate three intermediates (O 2ads → OOH ads → O ads → OH ads → H 2 O), leading to the formation of abundant ROS . Importantly, these intermediates exhibit distinct lifetimes and oxidation abilities, such as ·OH (with lifetimes ranging from approximately 10 –9 to 10 –6 s; E 0 (OH·/OH – ) = +1.9 to +2.7 V NHE ) and O 2 ·– (with a lifetime of approximately 60 s; E 0 (O 2 ·– /O 2 2– ) = ∼+1.69 V NHE ), which undergo different ECL reaction pathways, contributing to potential-resolved luminol ECL behaviors.…”