Suzuki cross-coupling polymerisation of aryldibromides and aryldiboronate esters in a sodium dodecyl sulfate (SDS)-stabilised miniemulsion provides a versatile and direct route to fluorescent conjugated polymer nanoparticles (CPNs). These nanoparticles have a conjugated backbone based on poly(9,9-dioctylfluorene) (PFO), however, significant structural diversity is introduced by incorporation of electron withdrawing, heterocyclic comonomers (5-50 mol. %) in order to tune the emission wavelengths from blue to far-red/near-infrared. The robust nature of the polymerisation methodology allows for rapid assessment of the relationship between polymer composition, chain morphology and optical properties of the resultant CPNs. Moreover, the CPNs (after a simple and rapid purification step) can be used directly in fluorescence-based intracellular labelling experiments (in HCT116 cells), in which they display low cytotoxicity at biologically-useful concentrations.

The photochemical and photophysical properties of porphyrins and their derivatives make them useful materials in catalysis, photovoltaics, and biomedicine. The range of applications may be broadened through the synthesis of porphyrin-containing polymers. Polymers based on porphyrins may be prepared by radical polymerization and coupling reactions such as esterification, amidation, and click chemistry. In this work, we demonstrate the successful synthesis of polyesters containing porphyrin moieties in the backbone using Candida antarctica lipase B (CALB) as a catalyst in a two-step methodology comprising ring-closure and ring-opening reactions. The enzymatic reactions were facilitated by the addition of tri­(ethylene glycol) spacers to circumvent the bulkiness of the prophyrinic structure in the substrates. A tetraphenylporphyrin-based macrocyclic lactone was first synthesized and characterized and then polymerized to yield polyesters with good thermal stability and optical properties similar to those of their porphyrinic precursors. Films may be cast from the polymers dissolved in organic solvents. The thermal and mechanical properties of the polyesters have been studied.

Porphyrins and their derivatives have been widely used in catalysis, energy conversion, photonics, and biomedicine; however, their use in biological applications is restricted by their limited solubility in aqueous systems. We have prepared a water-soluble copolymer containing moieties of naturally occurring protoporphyrin IX using direct copolymerization of a poly(ethylene glycol) (PEG) methacrylate monomer with protoporphyrin IX via free-radical polymerization. The content of protoporphyrin IX in the copolymer was determined by 1H NMR and UV–vis absorption spectroscopies. Their solution properties and the photostability of the protoporphyrin IX moiety in the copolymer provide direct evidence of the covalent incorporation of protoporphyrin IX within the copolymer. The copolymer showed a reversible phase transition in aqueous solution due to the lower critical solution temperature (LCST). The phase transition temperature varies with the pH of the solutions because of the protonation of the carboxylic acid groups. This copolymer may be useful as an alternative thermoresponsive material for biomedical applications.

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