Abstract
Diagnostic assays for developing countries have a prerequisite of low-cost along with high sensitivity and specificity. Paper, a commonly available material, provides a great economical and portable platform for fabricating biosensors. The present work focuses on the fabrication of a paper-based analytical device (PAD) using commonly accessible materials. The electrodes have been drawn using a pencil followed by filling with in-house prepared graphite ink and the barrier wall around the detection/sample zone has been prepared using a glue gun. The PAD has been developed in 2-dimensional (2D) and 3-dimensional (3D) designs. The principle of antibody-antigen interactions has been used for the realization of an economical and highly selective paper-based biosensor for E. coli O157:H7, paving way for economically weaker sections of the society to monitor their health. The electrochemical measurement results on paper substrate have turned out to be highly promising for the advancement of paper-based point-of-care (POC) diagnostics for pathogens like E. coli O157:H7.
Acknowledgement
The authors would like to offer special gratitude to late Prof. Vinay Gupta whose achievements and unparalleled dedication towards work remain a constant source of support and motivation. He continues to inspire us even today when he is no longer amongst us. The authors gratefully acknowledge the Defence Institute of Physiological and Allied Research (DIPAS), a laboratory of the Defence Research and Development Organization (DRDO), India for providing the E. coli cell culturing facilities. One of the authors, Nidhi Dhull, is thankful to CSIR (Council of Scientific & Industrial Research) for the research fellowship.