Size-Dependent Inhibition and Enhancement by Gold Nanoparticles of Luminol−Ferricyanide Chemiluminescence

Abstract

It was found that gold nanoparticles of small size (<5 nm) could inhibit the chemiluminescence (CL) of the luminol-ferricyanide system, whereas gold nanoparticles of large size (>10 nm) could enhance this CL, and the most intensive CL signals were obtained with 25-nm-diameter gold nanoparticles. The luminophor was identified as the excited-state 3-aminophthalate anion. The studies of UV-visible spectra, CL spectra, X-ray photoelectron spectra, effects of concentrations of luminol and ferricyanide solution, and fluorescence quenching efficiency of gold colloids were carried out to explore the CL inhibition and enhancement mechanism. The CL inhibition by gold nanoparticles of small size was supposed to originate from the competitive consumption of ferricyanide by gold nanoparticles and the relatively high quenching efficiency of the luminophor by gold nanoparticles. In contrast, the CL enhancement by gold nanoparticles of large size was ascribed to the catalysis of gold nanoparticles in the electron-transfer process during the luminol CL reaction and the relatively low quenching efficiency of the luminophor by gold nanoparticles. This work demonstrates that gold nanoparticles have the size-dependent inhibition and enhancement in the CL reaction, proposing a perspective for the investigation of new and efficient nanosized inhibitors and enhancers in CL reactions for analytical purposes.

Size/Shape–Property Relationships of Non‐Carbonaceous Inorganic Nanoparticles and Their Environmental Implications

“…In a different study monitoring the hydrogenation of anthracene, a polycyclic aromatic hydrocarbon pollutant, nanoparticles ranging from 4.1 to 24.7 nm displayed an increasing turnover frequency (number of anthracenes reduced per surface atom per second) with decreasing size (Deng et al , 2005(Deng et al , , 2007. Similar variation has been observed for other precious metal nanoparticle systems (Sharma et al , 2003 ;Duan et al , 2007 ).…”

Particle size dependence of the charging of Au nanoparticles immobilized on a modified ITO electrode

“…Elucidation of the optimal size is indispensable for the use as an optical signal enhancer and a catalyst. For example, size dependencies of enhancement of optical signals [20][21][22][23], molecular adsorption and cross-linking structure formation [24], and catalytic activities for reduction of organic compounds [25] have been extensively studied. The key factors of the size dependence include not only the surface density of coordinatively unsaturated Au atom [25] and electronic structure of NPs but also the charging-discharging properties of the particles.…”

Gold nanoparticle-enhanced luminol/ferricyanide chemiluminescence system for aristolochic acid-I detection in medicinal plants and slimming products

“…If the prepared AuNPs are less than 5 nm, the CL reaction of luminol and ferricyanide will be quenched due to the high surface energy produced from the small particles which will cause high redox activity. Meanwhile, the particle size of AuNPs more than 10-100 nm will enhance the CL reaction due to the change in oxidation state of AuNPs and the catalytic enhancement involved in the process of electron transfer (29). The CL reaction of luminol with hydrogen peroxide was also enhanced in the presence of AuNPs due to the breaking down of hydrogen peroxide to superoxide.…”