A test system for the printing of functional nucleic acids onto different carriers and verification of its functionality by DNA dyes

Abstract

The creation of inkjet printed biosensors belongs to rising applications of functional printing. One of their many uses is the detection of antibiotic residues in milk or meat from food-producing animals, which have been excessively treated. For example, they are treated with the fluoroquinolone ciprofloxacin (CFX), which we want to detect with an aptamer-based fluorescence biosensor, printed onto a carrier material. For that purpose, inkjet printing and several carrier materials are analyzed in their ability to obtain the functionality of nucleic acids. The printing process is analyzed by characterizing DNA and buffer solutions and by comparing printed with unprinted DNA using an agarose-gel test. The carrier materials are preselected by analyzing the auto-fluorescence excitation and emission spectra of ten different materials out of which three with the lowest intensity at the CFX excitation and emission peaks are chosen. After printing with DNA onto these materials, the fluorescence induced with DNA dyes is measured. The experiments show that nucleic acids can be inkjet printed without damage and that many foils and papers commonly used in the laboratory show auto fluorescence when excited in the UV-spectrum. Other properties of the carrier materials are important as well. Here a selection containing the paper Whatman Grade 1, the foil Hostaphan GUV 4600 and the nitrocellulose HF 120 are compared in their ability to sustain the functionality of nucleic acids printed onto them. Although, we were able to select a suitable material for future experiments of printing a CFX-biosensor, there are still open questions concerning the interactions between nucleic acids and different carrier materials.