Paper microfluidic devices for forensic serology

A method of fabricating a microfluidic device, the method comprising:

• providing a substrate;
• providing a pattern on the substrate including one or more channels, and one or more test spots on the channels, respectively;
• providing wax on the substrate, said wax outlining and surrounding each channel of the one or more channels except a portion of each channel that receives a test sample when in use;
• providing a tab protruding from the substrate and comprising a proximal end and a distal end opposite to the proximal end, said tab configured such that the distal end contacts a test sample when in use;
• and
• providing one or more colorimetric test reagents in each test spot;
• the one or more colorimetric test reagents being suitable for testing for bodily fluids,
• the distal end of the tab being free from wax,
• the plurality of channels and the plurality of test spots comprising at least one of the following:
• a first channel, having a first test spot and a first colorimetric test reagent suitable for testing for feces;
• a second channel, having a second test spot and a second colorimetric test reagent suitable for testing for vaginal fluid;
• a third channel, having a third test spot and a third colorimetric test reagent suitable for testing for perspiration, and
• the plurality of channels and the plurality of test spots further comprising:
• a fourth channel, having a fourth test spot and a fourth colorimetric test reagent that comprises phenolphthalein, ethanol, and sodium perborate for testing for blood;
• a fifth channel, having a fifth test sot and a fifth colorimetric test reagent that comprises acid phosphatase spot reagent for testing for semen;
• a sixth channel, having a sixth test spot and a sixth colorimetric test reagent that comprises starch and iodine for testing for saliva;
• and
• a seventh channel, having a seventh test spot and a seventh colorimetric test reagent that comprises urease and Nessler's reagent for testing for urine.

A microfluidic device comprising:

• a paper substrate;
• a wax pattern on the paper substrate and comprising a plurality of channels and a central stem that feeds into the plurality of channels, the wax of said wax pattern outlining and surrounding each channel of the plurality of channels except a portion of each channel that receives a test sample when in use;
• a tab protruding from the paper substrate and comprising a proximal end and a distal end opposite to the proximal end, said tab configured such that the distal end contacts a test sample when in use;
• a plurality of test spots on the channels, respectively;
• and
• a colorimetric test reagent in each test spot;
• the distal end of the tab being free from wax;
• each colorimetric test reagent being suitable for testing for bodily fluids;
• the plurality of channels and the plurality of test spots comprising the following:
• a first channel, having a first test spot and a first colorimetric test reagent suitable for testing for blood;
• a second channel, having a second test spot and a second colorimetric test reagent suitable for testing for semen;
• a third channel, having a third test spot and a third colorimetric test reagent suitable for testing for urine;
• a fourth channel, having a fourth test spot and a fourth colorimetric test reagent suitable for testing for saliva;
• a fifth channel, having a fifth test spot and a fifth colorimetric test reagent suitable for testing for feces;
• a sixth channel, having a sixth test spot and a sixth colorimetric test reagent suitable for testing for vaginal fluid;
• and
• a seventh channel, having a seventh test spot and a seventh colorimetric test reagent suitable for testing for perspiration,
• the first colorimetric test reagent comprising phenolphthalein, ethanol, and sodium perborate for testing for blood;
• the second colorimetric test reagent comprising acid phosphatase spot reagent for testing for semen;
• the third colorimetric test reagent comprising urease and Nessler's reagent for testing for urine;
• and
• the fourth colorimetric test reagent comprising starch and iodine for testing for saliva.