**Author details**

Charlton van der Horst1 , Bongiwe Silwana<sup>2</sup> , Emmanuel Iwuoha1 and Vernon S. Somerset3 \*

\*Address all correspondence to: somersetv@cput.ac.za

1 SensorLab, Department of Chemistry, University of the Western Cape, Bellville, South Africa

2 Department of Chemistry, Durham University, Durham, United Kingdom

3 Department of Chemistry, Faculty of Applied Sciences, Cape Peninsula University of Technology, Bellville, South Africa
