Chemical sensors play an important role in our understanding of chemical and biological systems, providing sensitive and rapid detection of a variety of substrates. Array-based sensing approaches avoid the ongoing challenge of designing and synthesizing selective receptors for particular analytes, a labor-intensive process that can frustrate the development of sensors. Instead, cross-reactive sensor arrays utilize multiple sensing elements that interact uniquely with each analyte and produce a distinct pattern of responses, enabling identification. To date, there are a variety of strategies both to gain cross-reactivity and diversity of sensors required for array-based sensing, and to broaden the scope of analytes for detection. Sensor arrays constructed using macromolecular components, such as polymers and nanoparticles, offer an attractive route to the discrimination of multiple, similar analytes, particularly within the context of biological sensing, where recognition over large areas is often required. Here, we focus on macromolecular sensing arrays underpinned by optical detection methods, which can enable rapid, sensitive detection of a range of analytes. We discuss the current state-ofthe art and explore the challenges to be overcome in translating exciting scientific advances to applications beyond the laboratory.

A thiocoumarin that exhibits varying fluorescence responses to metal ions in different solvents can be used in a single-probe multiple-solvent array for distinguishing metal ions.

Platinum complexes remain frontline anticancer therapies, even after 50 years of usage in clinical applications. However, there is still a lack of methodology to robustly detect and quantify these complexes in biological fluids. We report here a fluorescent sensor array comprising six sensors that demonstrates progress toward the detection of platinum levels in chemotherapy patients. Linear discriminant analysis was performed to examine each multidimensional data set, and the array was able to discriminate platinum from other biologically relevant metals and heavy metals and separately able to differentiate and identify platinum complexes with different coordination environments with 100% accuracy. Finally, the array showed sensitivity to various cisplatin and oxaliplatin concentrations in human plasma and was able to discriminate between a cohort of 27 cancer patients at different stages of platinum treatment. We envisage that our array system could lead to a better understanding of blood platinum concentrations of chemotherapy patients and could inform the modification of dosage regimes to minimize dose-limiting side effects.

No abstract

The use of stable isotope ratio mass spectrometry (IRMS) as a profiling tool for methylamphetamine has evolved over the last decade. Stable isotope ratios of carbon (δ C), nitrogen (δ N), and hydrogen (δ H) of methylamphetamine are useful in determining the precursor used to manufacture methylamphetamine, and in many cases the synthetic origin of the methylamphetamine precursor. More recently, samples of seized methylamphetamine show that a resolution step is being employed in the manufacturing process. We sought to determine whether the δ C, δ N, and δ H values were affected by either a resolution performed on racemic methylamphetamine or a resolution on racemic ephedrine, a commonly used precursor to methylamphetamine. We found that for the types of resolution studied, IRMS is still able to provide useful information on the provenance of a methylamphetamine sample.

No abstract