Vitamin C derivatives as new coreactants for tris(2,2'-bipyridine)ruthenium(II) electrochemiluminescence

Detection of 1,3-dihydroxyacetone by tris(2,2'-bipyridine)ruthenium(II) electrochemiluminescence

1,3-Dihydroxyacetone, a common cosmetic material and food additive, has been successfully explored as an efficient electrochemiluminescence coreactant of Ru(bpy)₃²⁺ for the first time. It is about 25 times more effective than the well-known coreactant sodium oxalate. The high electrochemiluminescence efficiency allows sensitive detection of 1,3-dihydroxyacetone without any derivatization. The electrochemiluminescence method shows two linear electrochemiluminescence responses over the range of 5.0-500 μM and 500 μM-6.0 mM with a detection limit of 1.79 μM. The proposed method is at least two orders of magnitude more sensitive than other reported methods. Graphical abstract ECL intensity-potential profile of 1,3-dihydroxyacetone (DHA) and oxalate.

Ferrocyanide-Ferricyanide Redox Couple Induced Electrochemiluminescence Amplification of Carbon Dots for Ultrasensitive Sensing of Glutathione

Here we report a novel solid-state ECL sensor for ultrasensitive sensing of glutathione (GSH) based on ferrocyanide-ferricyanide redox couple (Fe(CN)6(3-/4-)) induced electrochemiluminescence (ECL) amplification of carbon dots (C-dots). The electropolymerization of C-dots and (11-pyrrolyl-1-yl-undecyl) triethylammonium tetrafluoroborate (A2) enabled immobilization of the hydrophilic C-dots on the surface of glassy carbon electrode (GCE) perfectly, while the excellent conductivity of polypyrrole was exploited to accelerate electron transfer between them. The Fe(CN)6(3-/4-) can expeditiously convert the C-dots and S2O8(2-) to C-dot(•-) and SO4(•-), respectively. High yields of the excited state C-dots (C-dots*) were obtained, and a ∼10-fold ECL amplification was realized. The C-dots* obtained through the recombination of electron-injected and hole-injected processes may be impeded due to the interference of GSH to K2S2O8. Therefore, the constructed sensor for GSH showed a detection limit down to 54.3 nM (S/N = 3) and a wide linear range from 0.1-1.0 μM with a correlation coefficient of 0.997.

Recent advances in electrochemiluminescence

The great success of electrochemiluminescence (ECL) for in vitro diagnosis (IVD) and its promising potential in light-emitting devices greatly promote recent ECL studies. More than 45% of ECL articles were published after 2010, and the first international meeting on ECL was held in Italy in 2014. This critical review discusses recent vibrant developments in ECL, and highlights novel ECL phenomena, such as wireless ECL devices, bipolar electrode-based ECL, light-emitting electrochemical swimmers, upconversion ECL, ECL resonance energy transfer, thermoresponsive ECL, ECL using shape-controlled nanocrystals, and ECL as an ion-selective electrode photonic reporter, a paper-based microchip, and a self-powered microfluidic ECL platform. We also comment on the latest progress in bioassays, light-emitting devices and, the computational approach for the ECL mechanism study. Finally, perspectives and key challenges in the near future are addressed (198 references).

Ruthenium polypyridine complexes combined with oligonucleotides for bioanalysis: a review

Ruthenium complexes are among the most interesting coordination complexes and they have attracted great attention over the past decades due to their appealing biological, catalytic, electronic and optical properties. Ruthenium complexes have found a unique niche in bioanalysis, as demonstrated by the substantial progress made in the field. In this review, the applications of ruthenium complexes coordinated with polypyridine ligands (and analogues) in bioanalysis are discussed. Three main detection methods based on electrochemistry, electrochemiluminescence, and photoluminscence are covered. The important targets, including DNA and other biologically important targets, are detected by specific biorecognition with the corresponding oligonucleotides as the biorecognition elements (i.e., DNA is probed by its complementary strand and other targets are detected by functional nucleic acids, respectively). Selected examples are provided and thoroughly discussed to highlight the substantial progress made so far. Finally, a brief summary with perspectives is included.