Australians have the highest incidence of melanoma globally, despite increasing awareness of the risks of excessive sun exposure. Although excess ultraviolet radiation (UVR) can cause irreparable cell damage and lead to cancer, some exposure is vital to maintain bodily processes such as vitamin D production. For an individual, finding the balance between healthy exposure and skin damage is largely guesswork. The ability to provide a simple, individualised indicator of cumulative UVR dosage could be transformative in preventing skin cancer. This review will provide a brief overview of the variety of UVR sensor technologies and explain the important role of colourimetric dosimeters. The chemistry behind some recent examples of colourimetric dosimeters will be discussed, identifying that molecular photoswitches are ideal candidates to enable this technology. We discuss the chemical mechanisms of photoswitches and how to modify their chemical structure to optimise their properties for use as dosimeters. Through this lens, diarylethenes have been identified as prime dosimeter candidates, owing to their sensitivity, stability, adaptability and the variety of visually striking colours possible. Finally, some specific challenges are identified in the design and fabrication of personalised colourimetric dosimeters that can equitably meet the requirements of all users in our community.

Biomass valorisation through the selective oxidation of carbohydrate and lipid derivatives offers access to an array of platform chemicals through energy- and atom-efficient catalytic processes. Supported metal nanoparticles are promising catalysts for the aerobic selective oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA), but typically require strong liquid base to achieve high selectivity. Here, we explore the utility of MgO as a solid base support for the Ru-catalysed aerobic oxidation of HMF, obtaining 68% FDCA yield at 160°C and 1.5 MPa of O2 using <1 mol-% metal.

Self-assembled monolayers were first described in the 1980s and have now become ubiquitous in many interfacial technologies. In this account, we discuss different self-assembled monolayer systems, outlining their positives and negatives. We then overview other researchers’ work and our own group’s journey in using self-assembled monolayers to develop new concepts in sensing and addressing general challenges faced by many types of sensors. Finally, we reflect on some of the challenges monolayer chemistry needs to address to facilitate further use of this powerful surface chemistry in commercial devices.

Five new coordination polymers, namely [Ln(L)(NO3)2]n (Ln = La (1), Pr (2) and Sm (3)), [Eu(L)(NO3)2·1.5H2O]n (4) and [Tb(L)(OAc)2(H2O)·3H2O]n (5) (HOAc = CH3COOH), were synthesised by reaction of lanthanide nitrates with 1,3-bis(4-carboxybenzyl)benzimidazolium chloride (H2L+Cl−) under solvothermal conditions. All the coordination polymers were characterised by powder X-ray diffraction, infrared spectroscopy, thermogravimetric analysis, elemental analysis and single crystal X-ray diffraction. Complexes 1–5 exhibit two different 2-D structures due to the variation in reaction temperature. Complexes 1–4 are isostructural and crystallised in the monoclinic system, C2/c space group, showing a two-dimensional layer with Ln chains linked by L− ligands. Complex 5 crystallised in the P21/n space group, featuring a 2-D layer different from 1–4 with Tb dimers linked by L− ligands through carboxylates. Further, the luminescence properties of complexes 3–5 were investigated. In addition, the fluorescence lifetime and quantum efficiency of complex 4 were measured.

After a brief review of electronic nose technology, the use of an Australian electronic nose to identify an unknown odour out of a set of known odours is described. Multivariate supervised learning is accomplished by applying Bayes’ theorem to data from metal oxide semiconductor sensors responding to each of a number of target odours. An odour from an unknown source is then assigned a probability of membership of each of the training sets by applying either a Naïve Bayes algorithm to the deemed independent data from each sensor, or to a multinormal distribution of the data. A flat prior (equal probabilities of each outcome) is usually adopted, but for particular situations where one odour is known to predominate, then suitably weighted priors can be used. A source ‘none of the above’, which has a small likelihood covering the space of the possible sensor responses, is included for completeness. This also avoids the assignment to a source that has an extremely small probability but which is greater than that of any other source. Examples are given of a single source (detecting diabetes from a patient’s breath), and three sources of unpleasant odours in a meat processing plant.

Peptide therapeutics play an increasingly important role in modern drug discovery. Improving the pharmacokinetic profile of bioactive peptides has been effectively achieved with chemical modifications, especially macrocyclisation reactions. Consequently, there is a great demand for highly constrained compounds such as bicyclic peptides. In our previous research, we introduced peptide–bismuth bicycles and peptide–arsenic bicycles as new classes of constrained peptides. In this work, we extend our peptide bicyclisation strategy towards antimony. Similar to arsenic and bismuth, antimony(III) selectively binds to three cysteine residues in peptides, enabling the in situ formation of stable bicycles. The bicyclisation reaction occurs instantaneously under biocompatible conditions at physiological pH. Antimony–peptide bicycles remain largely intact in the presence of the common metal chelator ethylenediaminetetraacetic acid (EDTA) and the main endogenous thiol competitor glutathione (GSH). Furthermore, when challenged with bismuth(III) from water-soluble gastrodenol (bismuth tripotassium dicitrate), antimony–peptide bicycles convert into the corresponding bismuth–peptide bicycle, highlighting the superior thiophilicity of bismuth over other pnictogens. Our study further expands the toolbox of peptide multicyclisation with main group elements previously underexplored in chemical biology.