Rapid and Onsite Detection of Fuel Adulteration.

In numerous developing countries, the lower cost of subsidized liquid fuels such as kerosene compared to market-rate fuels often results in fuel adulteration. Such misuse of kerosene is hard to detect with conventional detection technologies because they are either time consuming, expensive, not sensitive enough or require well-equipped analytical laboratories. In this work, we developed an inexpensive and easy-to-use device for rapid and onsite detection of fuel adulteration. The working principle of our fuel adulteration detection is sensing changes in the mobility of fuel droplets on non-textured (i.e., smooth) and non-polar solid surfaces. Using our device, we demonstrated rapid detection of diesel (market-rate fuel) adulterated with kerosene (subsidized fuel) at concentrations an order of magnitude below typical adulteration concentrations. We envision that our inexpensive, easy-to-use, and field-deployable device as well as the design strategy will pave the way for novel fuel quality sensors.