Low-cost, high-speed identification of counterfeit antimalarial drugs on paper.
With the emergence of artesunate antimalarial counterfeiting in Southeast Asia and sub-Saharan Africa, we present the production of a rapid, inexpensive and simple colorimetric-based testing kit for the detection of counterfeit artesunate in order to preserve life and prevent the development of multi-drug resistant malaria. The kit works based on paper microfluidics which offer several advantages over conventional microfluidics, and has great potential to generate inexpensive, easy-to-use, rapid and disposable diagnostic devices. Here, we have developed a colorimetric assay that is specific to artesunate and turns yellow upon addition of the sample. The test can be done within minutes, and allows for a semi-quantitative analysis of the artesunate tablets by comparing the developed yellow color on the paper test to a color-coded key chart that comes with the kit. A more accurate and precise analysis is done by utilizing a color analyzer on an iPhone camera that measures the color intensity of the developed color on the paper chip. A digital image of the chip was taken and analyzed by measuring the average gray intensity of the color developed on the paper circle. A plot of the artesunate concentration versus the average gray scale intensity was generated. Results show that the intensity of the yellow color developed on the paper test was consistent and proportional to the amount of artesunate present in the sample. With artesunate concentrations ranging from 0.0 to 20mg/mL, a linear calibration plot was obtained with a detection limit of 0.98 mg/mL.
['Koesdjojo|Myra T|MT|', 'Wu|Yuanyuan|Y|', 'Boonloed|Anukul|A|', 'Dunfield|Elizabeth M|EM|', 'Remcho|Vincent T|VT|']
D000962:Antimalarials D037621:Artemisinins D000077332:Artesunate D001210:Asia, Southeastern D003124:Colorimetry D058110:Counterfeit Drugs D006801:Humans D008288:Malaria D044085:Microfluidics D010209:Paper D013607:Tablets
Artesunate Malaria Paper microfluidics Colorimetric assay Fabrication