Pad printing inks based on reduced graphene oxide and various cellulose binders: Rheological properties, printability and application in electrochemical sensors

Pad printing is not a widely used printing technique, but it offers the possibility of a simple, fast, and low-cost production of various high-resolution electrode structures. Here, the pad-printed reduced graphene oxide (rGO) electrodes are prepared from pad-printable inks containing rGO powder and different concentrations of two cellulose-based polymers: ethylcellulose and cellulose acetate butyrate. The applicability of rGO inks for pad printing is analyzed according to their rheological parameters and printability. Based on viscosity, storage (G') and loss modulus (G'') values, 10wt% of ethylcellulose and 15 wt% of cellulose acetate butyrate appear to be most suitable for pad printing. The effect of polymer concentration on rGO electrodes homogeneity and mechanical stability is also evaluated. Cyclic voltammetry measurements for [Fe(CN)(6)](3-/4-) redox system are performed with rGO/cellulose inks pad-printed onto transparent conductive oxide substrates with the best results when using ethylcellulose as a binder. Finally, the square-wave voltammetric method assesses the viability of rGO electrodes for the fast detection of ascorbic acid (detection limit of 15 mu M) coupled with satisfactory precision (4.5%, n = 5) and long-term stability during electrochemical measurements.

Automated summary

This study demonstrates the preparation of pad-printable inks containing reduced graphene oxide (rGO) and cellulose-based polymers (ethylcellulose and cellulose acetate butyrate) for pad printing. The most suitable polymer concentrations for pad printing are determined based on rheological parameters and printability analysis. The resulting rGO electrodes, printed with ethylcellulose as a binder, show good performance in detecting ascorbic acid.