Decorated carbon nanotubes with unique oxygen sensitivity

Abstract

The relatively simple and robust architecture of microelectronic devices based on carbon nanotubes, in conjunction with their environmental sensitivity, places them among the leading candidates for incorporation into ultraportable or wearable chemical analysis platforms. We used single-walled carbon nanotube (SWNT) networks to establish a mechanistic understanding of the solid-state oxygen sensitivity of a Eu(3+)-containing dendrimer complex. After illumination with 365 nm light, the SWNT networks decorated with the Eu(3+) dendrimer show bimodal (optical spectroscopic and electrical conductance) sensitivity towards oxygen gas at room temperature under ambient pressure. We investigated the mechanism of this unique oxygen sensitivity with time-resolved and steady-state optical spectroscopy, analysis of excited-state luminescence lifetimes and solid-state electrical transport measurements. We demonstrate a potential application of this system by showing a reversible and linear electrical response to oxygen gas in the tested range (5-27%).

Novel antennae for the sensitization of near infrared luminescent lanthanide cations

“…As an example of this flexibility, we have recently created a solid-state system for the sensing of oxygen by coating carbon nanotubes with dendrimers that possess a different lanthanide sensitizer: a derivative of the 1,8-naphthalimide group. In comparison to the previously described derivative of 2,3-naphthalimide, the electronic state of this sensitizer has a triplet state which is located lower in energy, a desirable property to promote interaction between the sensing part and the molecules of oxygen [69]. Another originality of this new system is that it offers a way to analyze the electronic structure of the dendrimerlanthanide complex.…”

Looking for the Origin of Allosteric Cooperativity in Metallopolymers

“…On the contrary, the less studied lanthanide‐containing metallopolymers belonging to Type I and Type II categories are compatible with the complete or partial filling of the available sites with one or different lanthanide complexes, this without altering the polymeric structures (Figure ). Polynuclear systems with programmed sequences of (open‐shell) metal ions thus become available, a key step to push further ahead with current limits of optical sensing, directional light‐downshifting and energy‐transfer light‐upconversion . As a starting point for bringing Type I or Type II metallopolymers L N within the frame of chemical control, one can benefit from the fact that the thermodynamics of metal loading in these linear metallopolymers is easily caught by a simple model (Figure a), which considers only two free energy parameters: the intermolecular affinity of a single site for the entering metal, M, in the polymer L N and the energetic penalty >0, or benefit <0, produced by a bound site for the fixation of a second metal to an adjacent free site in the polymer L N .…”

“…[27,28] On the contrary,t he less studied lanthanide-containing metallopolymers belonging to Type Ia nd Type II categories [5] are compatible with the complete or partial filling of the availables ites with one or different lanthanide complexes,t his without altering the polymeric structures ( Figure 1). Polynuclear systems with programmed sequences of (open-shell) metal ions thus becomea vailable,akey step to push further ahead with current limits of optical sensing, [29][30][31] directional light-downshifting [32,33] and energy-transfer light-upconversion. [34] As as tartingp oint for bringing Type Io rT ype II metallopolymers L N within the frame of chemical control,o ne can benefitf rom the fact that the thermodynamicso fm etal load-Scheme1.Wolf Type I-III strategies for the introduction of metal centers into organic polymers.…”

Quantitative nanoscale visualization of heterogeneous electron transfer rates in 2D carbon nanotube networks

“…Understanding heterogeneous electron transfer (HET) at CNTs is of considerable importance, due to the wide range of electroanalytical and electrocatalytic systems based on CNTs (14)(15)(16)(17), and also because electrochemistry provides an attractive route to functionalize and tailor the properties of CNTs (18)(19)(20). Probing HET in 1D electrode materials is interesting fundamentally, given their inherent electronic structure and properties (21,22).…”