Photoinduced electrochemiluminescence (PECL) allows the electrochemically assisted conversion of low-energy photons into high-energy photons at an electrode surface. This concept is expected to have important implications, however, it is dramatically limited by the stability of the surface, impeding future developments. Here, a series of metal-insulator-semiconductor (MIS) junctions, using photoactive n-type Si (n-Si) as a light absorber covered by a few-nanometerthick protective SiO x /metal (SiO x /M, with M = Ru, Pt, and Ir) overlayers are investigated for upconversion PECL of the model co-reactant system involving the simultaneous oxidation of tris(bipyridine)ruthenium(II) and tri-n-propylamine. We show that n-Si/SiO x /Pt and n-Si/SiO x /Ir exhibit high photovoltages and record stabilities in operation (35 h for n-Si/SiO x /Ir) for the generation of intense PECL with an anti-Stokes shift of 218 nm. We also demonstrate that these surfaces can be employed for spatially localized PECL. These unprecedented performances are extremely promising for future applications of PECL.

Mitochondria are the subcellular bioenergetic organelles. The analysis of their morphology and topology is essential to provide useful information on their activity and metabolism. Herein, we report a label‐free shadow electrochemiluminescence (ECL) microscopy based on the spatial confinement of the ECL‐emitting reactive layer to image single living mitochondria deposited on the electrode surface. The ECL mechanism of the freely‐diffusing [Ru(bpy)3]2+ dye with the sacrificial tri‐n‐propylamine coreactant restrains the light‐emitting region to a micrometric thickness allowing to visualize individual mitochondria with a remarkable sharp negative optical contrast. The imaging approach named “shadow ECL” (SECL) reflects the negative imprint of the local diffusional hindrance of the ECL reagents by each mitochondrion. The statistical analysis of the colocalization of the shadow ECL spots with the functional mitochondria revealed by classical fluorescent biomarkers, MitoTracker Deep Red and the endogenous intramitochondrial NADH, validates the reported methodology. The versatility and extreme sensitivity of the approach are further demonstrated by visualizing single mitochondria, which remain hardly detectable with the usual biomarkers. Finally, by alleviating problems of photobleaching and phototoxicity associated with conventional microscopy methods, SECL microscopy should find promising applications in the imaging of subcellular structures.

HTL of Spirulina sp. byproducts was investigated for the production of road binders.

Electrochemiluminescence (ECL) is widely employed for medical diagnosis and imaging. Despite its remarkable analytical performances, the technique remains intrinsically limited by the essential need for an external power supply and electrical wires for electrode connections. Here, we report an electrically autonomous solution leading to a paradigm change by designing a fully integrated alloptical wireless monolithic photoelectrochemical device based on a nanostructured Si photovoltaic junction modified with catalytic coatings. Under illumination with light ranging from visible to nearinfrared, photogenerated holes induce the oxidation of the ECL reagents and thus the emission of visible ECL photons. The blue ECL emission is easily viewed with naked eyes and recorded with a smartphone. A new light emission scheme is thus introduced where the ECL emission energy (2.82 eV) is higher than the excitation energy (1.18 eV) via an intermediate electrochemical process. In addition, the mapping of the photoelectrochemical activity by optical microscopy reveals the minority carrier interfacial transfer mechanism at the nanoscale. This breakthrough provides an all-optical strategy for generalizing ECL without the need for electrochemical setups, electrodes, wiring constraints, and specific electrochemical knowledge. This simplest ECL configuration reported so far opens new opportunities to develop imaging and wireless bioanalytical systems such as portable point-of-care sensing devices.

Photoinduced electrochemiluminescence (PECL) allows the electrochemically assisted conversion of low‐energy photons into high‐energy photons at an electrode surface. This concept is expected to have important implications, however, it is dramatically limited by the stability of the surface, impeding future developments. Here, a series of metal‐insulator‐semiconductor (MIS) junctions, using photoactive n‐type Si (n‐Si) as a light absorber covered by a few‐nanometer‐thick protective SiOx/metal (SiOx/M, with M=Ru, Pt, and Ir) overlayers are investigated for upconversion PECL of the model co‐reactant system involving the simultaneous oxidation of tris(bipyridine)ruthenium(II) and tri‐n‐propylamine. We show that n‐Si/SiOx/Pt and n‐Si/SiOx/Ir exhibit high photovoltages and record stabilities in operation (35 h for n‐Si/SiOx/Ir) for the generation of intense PECL with an anti‐Stokes shift of 218 nm. We also demonstrate that these surfaces can be employed for spatially localized PECL. These unprecedented performances are extremely promising for future applications of PECL.

Wireless electrochemical systems constitute a rapidly developing field. Herein, photo-induced electrochemiluminescence (PECL) is studied at Si-based closed bipolar electrodes (BPEs) for designing anti-Stokes systems that can convert IR into visible photons, without direct electrical contact. We show that protection of the anodic emitting pole of the BPE allows the triggering of bright and longstanding emission under the synergetic actions of an external bias and IR illumination. Photoactive nand p-type Si BPEs are studied with front-side and back-side illumination, respectively, and non-photoactive n + -Si BPEs are studied in the dark. Two electrochemiluminescent (ECL) systems ([Ru(bpy) 3 ] 2+ /TPrA and L-012) are tested and we show that the onset bias and the anti-Stokes shift can be controlled by the ECL system that is employed. These advances, rationalized by simulations, will be useful for the design of original PECL systems for chemical sensing or photodetection.

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Anti-Stokes photoinduced electrochemiluminescence (PECL) converts infrared photons to visible photons and is usually triggered at a narrow bandgap protected photoanode. Here, we report the first example of PECL with the...