Highly Efficient Electrogenerated Chemiluminescence of Au₃₈ Nanoclusters

Abstract

An investigation of mechanisms for the near-infrared (NIR) electrogenerated chemiluminescence/electrochemiluminescence (ECL) of Au38(SC2H4Ph)24 (Au38, SC2H4Ph = 2-phenylethanethiol) nanoclusters both in annihilation and coreactant paths is reported. Essentially, no ECL emission was produced in the annihilation route over the potential range of the accessible redox states of Au38, because of the short lifetime and/or low reactivity of the electrogenerated Au38 intermediates necessary for ECL. Highly efficient light emission with a nominal peak wavelength of 930 nm in the NIR region was observed in the anodic region upon addition of tri-n-propylamine (TPrA) as the coreactant. The ECL mechanisms were elucidated by means of ECL-potential curves and spooling ECL spectroscopy. It was discovered that the Au38(+*) (and also Au38(3+*)) were electrogenerated as the major excited species in the light emission processes. Benzoyl peroxide was also used as a coreactant in the cathodic potential range from which benzoate radicals, with a high oxidizing power, were formed. These radicals accepted electrons from the electrogenerated Au38(2-) HOMO, resulting in the Au38(-*) excited state that emitted light at 930 nm. The photoluminescence of the various Au38 charge states, namely, Au38(2-), Au38(-), Au38(0), Au38(+), Au38(2+), and Au38(4+), electrogenerated in situ, indicated no significant difference in the emission peak wavelength. This information allowed a careful mapping of the relevant ECL mechanisms. It was found that the ECL efficiency could reach an efficiency of 3.5 times as high as that of the Ru(bpy)3(2+)/TPrA system.

Benzoyl Peroxide as an Efficient Dopant for Spiro‐OMeTAD in Perovskite Solar Cells

“…[31,32] As as trong oxidant,B PO has been widely used in organic synthesis and oxidation polymerization of conducting polymers. [31,32] As as trong oxidant,B PO has been widely used in organic synthesis and oxidation polymerization of conducting polymers.…”

Enhanced Electrochemiluminescence of Luminol on Indium Tin Oxide Modified with Dendrimer‐Encapsulated Au Nanoparticles

“…We also carried out spooling ECL spectroscopy of the luminol/hydrogen peroxide system on Au DEN‐modified (top spooling ECL spectra in Figure 3c) and bare (bottom spooling ECL spectra in Figure 3c) ITOs in the same potential window as the ECL‐potential curves shown in Figure 3b, which allowed us to track the ECL spectra and intensity as a function of the applied potential (i.e. time) while scanning 41, so as to obtain further information on luminol ECL reactions on the ITO electrodes. As we observed in the ECL‐potential curves in Figure 3b, similar trends of ECL evolution and devolution were obtained on both the Au DEN‐modified and the bare ITO electrodes; especially, higher ECL emission was observed even at lower applied potentials on the Au DEN‐modified ITO than in one with the bare ITO (Figure 3c).…”

Recent Advances Based on Nanomaterials as Electrochemiluminescence Probes for the Fabrication of Sensors

“…Due to the good stability and easy synthesis procedure, the ECL performance of Au NCs with different molecular composition has been investigated including Au 25 + , Au 25 − , Au 38 , Au 25 , Au 144 and Au 8 . For example, our group utilized Au 8 as emitter to investigate the ECL performance in both organic solvent and aqueous solution with the annihilation reaction and co‐reactant routes .…”

“…For example, our group utilized Au 8 as emitter to investigate the ECL performance in both organic solvent and aqueous solution with the annihilation reaction and co‐reactant routes . Ding's group utilized electrochemistry, spooling spectroscopy and photoluminescent spectroscopy to demonstrate the mechanism of the Au NCs ECL and suggested that all accessible excited states of Au NCs emit the same wavelength . In recent years, NIR ECL emission of Au NCs with lower background interference and longer penetration depth has been extensively studied .…”