Self-reporting dynamic covalent polycarbonate networks

Here, we report the first-time development of polycarbonate networks with self-reporting thermoreversible bonding/debonding on demand properties. The reversible linkages within the network are based on a Hetero–Diels–Alder (HDA) moiety, which is able to undergo cleavage and rebonding as a function of temperature within minutes. As HDA pair a phosphoryl dithioester and a cyclopentadiene moiety are employed as bonding and debonding take place in the temperature range between 25–120 °C. The degradation and rebonding can be readily traced by visible inspection due to the self-reporting nature of the HDA moiety. In order to prove the reversibility, linear polycarbonates (Mw = 4.200–20.000 g mol−1) including the reversible linkage in each repeating unit were generated and carefully analyzed using size exclusion chromatography (SEC), UV/Vis analysis and high temperature 1H NMR spectroscopy. Subsequently, polycarbonate networks bearing HDA units – allowing the networks to be fully degraded into small molecules – were synthesized, debonded and bonded several times in the temperature range between 25 and 120 °C within minutes. The present study thus introduces fully degradable polycarbonate networks based on a facile chemical concept as a viable alternative to networks based on C–C bond formation that disallow a complete degradation

Prevent or Cure - The Unprecedented Need for Self-Reporting Materials

Self‐reporting smart materials are highly relevant in modern soft matter materials science, as they allow for the autonomous detection of changes in synthetic polymers, materials, and composites. Despite critical advantages of such materials, for example, prolonged lifetime or prevention of disastrous material failures, they have gained much less attention than self‐healing materials. However, as diagnosis is critical for any therapy, it is of the utmost importance to report the existence of system changes and their exact location to prevent them from spreading. Thus, we herein critically review the chemistry of self‐reporting soft matter materials systems and highlight how current challenges and limitations may be overcome by successfully transferring self‐reporting research concepts from the laboratory to the real world. Especially in the space of diagnostic self‐reporting systems, the recent SARS‐CoV‐2 (COVID‐19) pandemic indicates an urgent need for such concepts that may be able to detect the presence of viruses or bacteria on and within materials in a self‐reporting fashion

Untapped toolbox of luminol based polymers

The objective of the current Perspective article is to highlight the present state of luminol based polymers, with a specific emphasis on how to include luminol derivatives into polymer chains using both electrochemical and chemical techniques with an underline on new synthetic methods. Importantly, the current limitations that limit the expansion of polymeric luminol derivatives will be discussed by drawing attention to the challenges of solubilising monomers, the harsh conditions leading to undesired side reactions during the polymerization process or the necessity of orthogonal post-modification reactions. Importantly, the article discusses the remaining challenges within the field, while suggesting strategies for the advancement of this versatile class of polymers

Chemiluminescent self-reporting supramolecular transformations on macromolecular scaffolds

We introduce the synthesis of a self-reporting system with chemiluminescent output, which is regulated via dynamic supramolecular complex formation. By free radical polymerization and subsequent post-polymerization modification, a copolymer decorated with luminol and superbase (i.e. 1,5,7-triaza-bicyclo-[4.4.0]dec-5-ene (TBD)) moieties was synthesized, which in turn forms supramolecular host–guest-complexation with randomly methylated β-cyclodextrin (Me-β-CD). Upon hydrogen peroxide addition, the host–guest-interactions with the self-assembly are broken, and the luminol is oxidized to 3-aminophthalic acid (3-APA). Critically, no additional base, buffer or catalyst is required to generate the striking blue light emission of the polymeric system that is detectable by the naked eye. Thus, a fast and easy detection of reactive oxygen species (ROS), such as hydrogen peroxide, under mild conditions is established. The self-reporting system and its chemiluminescent properties are characterized by 1D and 2D NMR spectroscopy (particularly NOESY), dynamic light scattering (DLS), UV/Vis spectroscopy and chemiluminescence (CL) measurements

Photo-induced chemistry for the design of oligonucleotide conjugates and surfaces

A photocaged diene is introduced at the 5′-end of oligonucleotides using the H-phosphonate approach. The photoenol-functionalized DNA is subsequently employed for the conjugation to a protein and the spatially controlled immobilization onto surfaces using a light-induced Diels–Alder cycloaddition. Fully functional protein–DNA conjugates and patterned DNA surfaces are obtained under mild irradiation conditions