A nice paper in J Chem Ed just out (behind the paywall, but contacting author usually works). It introduces the concept of paper based diagnostics for the analysis of small amounts of sample. Essentially a small amount of paper cut out using a decorative paper punch is pre-treated with indicator and allowed to dry. Once dried, this can then be used to test a sample for acidity or whatever else is of interest. A drop of analyte is transferred to the paper using a swab or capillary tube.
The paper and supplementary information provides elaborate details of context based forensic scenarios, along with instructor and student directions (which are detailed but need a good edit). There’s lots of good stuff too on the scientific inquiry.The indicators test for “cyanide” – thankfully just hydroxide ions – and creatine. (I’m not sure I agree with the principle of pretending it’s cyanide, but that’s another matter).
Developing the idea:
It struck me that it could be interesting to develop this idea further, and get students at upper level/early undergraduate to develop a more elaborate matrix for testing a particular range of analytes – e.g. anions. Any suggestions welcome. What could be adsorbed and dried onto paper that would give a colour change with a drop of analyte. Clever chemists: hear the call!