Analytical Sciences

3,3′,5,5′-Tetramethylbenzidine Oxidation on Paper Devices for Horseradish Peroxidase-based Assays

Lori Shayne Alamo BUSA,*1,*2 Takeshi KOMATSU,*1 Saeed MOHAMMADI,*1 Masatoshi MAEKI,*3 Akihiko ISHIDA,*3 Hirofumi TANI,*3 and Manabu TOKESHI*3,*4,*5,*6

*1 Graduate School of Chemical Sciences and Engineering, Hokkaido University, Kita 13 Nishi 8, Kita, Sapporo 060-8628, Japan
*2 Physical Sciences Department, College of Arts and Sciences, Nueva Vizcaya State University, Bayombong, Nueva Vizcaya 3700, Philippines
*3 Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, Kita 13 Nishi 8, Kita, Sapporo 060-8628, Japan
*4 ImPACT Research Center for Advanced Nanobiodevices, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8603, Japan
*5 Innovative Research Center for Preventive Medical Engineering, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8601, Japan
*6 Institute of Innovative for Future Society, Nagoya University, Furo-cho, Chikusa, Nagoya 464-8601, Japan

We report on the colorimetric oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) by hydrogen peroxide using horseradish peroxidase on photolithography-fabricated (P-PAD) and wax-printed (W-PAD) paper-based analytical devices. Fabricating PADs via photolithography exposes the hydrophilic areas to polymers (photoresists) and solvents, not only reducing the hydrophilicity, but also affecting the TMB–H₂O₂ assay system with an unavoidable incomplete elimination of photoresist during fabrication. Detection signals are then observed in the presence of photoresist residues on the P-PAD, even at a blank HRP concentration.

J-STAGE: View this article in J-STAGE