Scientists at McMaster University have come up with a new methodology to create cheap biosensors using an inkjet printer. By applying a “lateral flow” sensing paradigm commonly seen in pregnancy test strips, the developers showed how one can implement a FujiFilm Dimatix Materials Printer to create sensors that can detect the presence of toxins, specifically acetylcholinesterase (AChE) inhibitors such as paraoxon and aflatoxin B1.
From a statement by McMaster:
The process involves formulating an ink like the one found in computer printer cartridges but with special additives to make the ink biocompatible. An ink comprised of biocompatible silica nanoparticles is first deposited on paper, followed by a second ink containing the enzyme, and the resulting bio-ink forms a thin film of enzyme that is entrapped in the silica on paper. When the enzyme is exposed to a toxin, reporter molecules in the ink change colour in a manner that is dependent on the concentration of the toxin in the sample.
This simple and cost-effective method of adhering biochemical reagents to paper is expected to bring the concept of bioactive paper a significant step closer to commercialization. The goal for bioactive paper is to provide a rapid, portable, disposable and inexpensive way of detecting harmful substances, including toxins, pathogens and viruses, without the need for sophisticated instrumentation. The research showed that the printed enzyme retains full activity for at least two months when stored properly, suggesting that such sensor strips should have a good shelf life.
Portable bio-sensing papers are expected to be extremely useful in monitoring environmental and food-based toxins, as well as in remote settings in less industrialized countries where simple bioassays are essential for the first stages of detecting disease.
Press release: Toxin detection as close as an inkjet printer …
Abstract in Analytical Chemistry: Development of a Bioactive Paper Sensor for Detection of Neurotoxins Using Piezoelectric Inkjet Printing of Sol-Gel-Derived Bioinks …
Image: This is topography of inkjet-sprayed PVAm, and AChE (50 U/mL) and DTNB doped sodium silicate (SS) thin films on paper. Credit: McMaster University
