Paper Test Strips Developed for Bioactivity

Hemoglobin tests printed on paper, the left half of which indicates that the sample does not contain detectable amounts of hemoglobin. Two bars running across the right side of the test means the sample does contain a detectable amount of hemoglobin. (VTT Technical Research Centre of Finland)

VTT Technical Research Centre of Finland in Espoo has developed a method of using printing technology to produce simple tests with treated paper to indicate the presence of bioactivity. VTT has demonstrated the feasibility of this method by printing a hemoglobin test paper that reveals whether a given sample contains hemoglobin (pictured right).

VTT says the paper is printed with antibodies that react to the sample. The test result can be read in the form of a line, for example, which either does or does not appear depending on the sample, much like over-the-counter pregnancy tests familiar to consumers. Using paper also makes it possible to print instructional images or text either on or alongside the test.

Printed paper tests can be used to show the presence of a given substance. The test can be adapted to different purposes by exchanging one identifying antibody printed on the paper for another. The paper can be manufactured using normal printing equipment. However, printing sensitive biomolecules requires different handling and storage procedures than those followed with normal printing inks.