Conductive Paper with Antibody-Like Film for Biomolecule detection

This work reports a simple and inexpensive way of producing a device that displays a sensitive response for a given biomolecule. The device consists in hydrophobic paper, covered by a graphite home-made ink and by a sensory material, a plastic antibody tailored on-site by an electrical stimulus.

The target biomolecule was carnitine, a potential biomarker in ovarian cancer. The concept presented herein may be extended to other biomolecules, including other cancer biomarkers

Authors and Affiliations:

Ana Patrícia Moreira Tavares, Nádia Silva Ferreira, Liliana Adelina Afonso Novo de Almeida Truta, Maria Goreti Ferreira Sales

BioMark-CINTESIS/ISEP, Instituto Superior de Engenharia do Porto, do Instituto Politécnico do Porto, Portugal

Abstract:

This work reports a novel way of producing a sensing film on an inexpensive substrate support, designed for electrical transduction of an intended biomolecule. The support uses cellulose paper as substrate, made hydrophobic with solid wax and covered by a home-made conductive ink having graphite as core material. The hydrophobicity of the paper was confirmed by contact angle measurements and the conductive ink composition was optimized with regard to its adhesion, conductivity, and thermal stability. This support was further modified targeting its application in quantitative analysis. Carnitine (CRT) was selected as target compound, a cancer biomarker. The recognition material consisted of an antibody-like receptor film for CRT, tailored on the support and prepared by electrically-sustained polymerization of 3,4-ethylenedioxythiophene (EDOT) or dodecylbenzenesulfonic acid (DBS). Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy analysis confirmed the presence of the polymeric film on the support, and the performance of the devices was extensively evaluated with regard to linear response ranges, selectivity, applicability, and reusability. Overall, the paper-based sensors offer simplicity of fabrication, low cost and excellent reusability features. The design could also be extended to other applications in electrical-based approaches to be used in point-of-care (POC).

Journal: Scientific Reports

Link: http://www.nature.com/articles/srep26132