Long-Term Stability Monitoring of Printed Proteins on Paper-Based Membranes

Abstract

Monitoring of long-term stability of proteins on paper-based membranes is important as it is directly related to paper-based sensor fabrication. By using a simple piezo printhead inkjet printer, recombinant proteins and antibodies were printed on paper-based membranes to test their stability and sensitivity under varying lengths of storage and temperature conditions. Our data show that a printed IgG-HRP antibody on simple printing paper maintains >50% functionality up to ∼2 months under 4 and -20 °C storage. Antibodies printed on polyvinylidene difluoride (PVDF) and nitrocellulose showed 5.3 and 9.7% decreases, respectively, in initial signal intensities compared to printing paper. Prostate-specific membrane antigen and tumor necrosis factor alpha recombinant proteins printed on paper-based membranes can be detected by antibodies, and antibody signal intensities can be detected up to 28 days after storage at 4 and -20 °C when printed on PVDF membrane or printing paper. These data suggest that printed proteins on simple printing paper and PVDF membrane can maintain their functionality up to few months when stored at 4 °C or lower and can be potentially applied in paper-based sensor development.

Figure 1

Anti IgG-HRP antibody printing on a paper-based platform. (A) Printing of anti-IgG-HRP antibody on a paper-based membrane, (B) printing scheme and printed IgG-HRP antibody on printing paper, (C) concentration of the anti-IgG-HRP antibody vs chemiluminescence intensity from printed anti-IgG-HRP. Each experiment was performed in triplicate, and values are expressed as the mean ± SD.

Figure 2

Stability of the printed anti-IgG-HRP antibody. (A) Chemiluminescence data from the printed IgG-HRP antibody (r.t. and −4 °C). −20 °C not shown. The chemiluminescence intensity profile from the printed anti-IgG-HRP antibody on (B) printing paper (C) nitrocellulose (D) PVDF after the designated storage period. Each experiment was performed in triplicate, and values are expressed as mean ± SD.

Figure 3

Printed TNF-α and PSMA detection on a paper-based platform. (A) Schematic image of the printed TNF-α and PSMA detection model, (B) chemiluminescence from printed TNF-α and PSMA. Chemiluminescence intensity profile from printed (C) PSMA and (D) TNF-α on a paper-based platform. Each experiment was performed in triplicate, and values are expressed as mean ± SD.

Figure 4

Stability of printed PSMA and TNF-α on a paper-based platform. The chemiluminescence profile from printed PSMA on (A) printing paper, (B) nitrocellulose, and (C) PVDF and from TNF-α on (D) printing paper, (E) nitrocellulose, and (F) PVDF membrane. Each experiment was performed in triplicate, and values are expressed as the mean ± SD.