Piezoelectric inkjet printing of a cross-hatch immunoassay on a disposable nylon membrane.

The development of a cost-effective method for manufacturing immunoassays is a key step towards their commercial use. In this study, a piezoelectric inkjet printer and a nylon membrane were used to fabricate a disposable immunoassay. Using a piezoelectric inkjet printer, a cross-hatch pattern of goat anti-mouse antibody (GalphaM) and rabbit anti-horseradish peroxidase (RalphaHRP) antibody were deposited on the nylon membrane. These patterns were subsequently treated with a solution containing rabbit anti-goat antibody labeled with horseradish peroxidase (RalphaG-HRP). The effectiveness of the immobilization process was examined using tetramethylbenzidine (TMB), which oxidizes in the presence of HRP to form a visible precipitate. Optical evaluation of the TMB precipitate was used to assess the precision of the features in the inkjet-printed pattern as well as antibody functionality following inkjet printing. Uniform patterns that contained functional antibodies were fabricated using the piezoelectric inkjet printer. These results suggest that piezoelectric inkjet printing may be used to fabricate low-cost disposable immunoassays for biotechnology and healthcare applications.