Silver‐Based Conductive Ink on Paper Electrodes Based on Micro‐Pen Writing for Electroanalytical Applications

AbstractNano‐silver conductive inks have attracted the attention of researchers due to their high electrical conductivity, good chemical stability, and wide applicability. As the mainstream conductive ink, it is mostly used in inkjet printing, but its application is limited due to the high sintering temperature. In this paper, silver nanoparticles were synthesized by reducing silver nitrate with sodium borohydride. Using silver nanoparticles as basic conductive fillers and graphene or copper nanoparticles as auxiliary conductive fillers, silver conductive inks, silver/graphene conductive inks and silver/copper conductive inks suitable for micro‐direct writing printing were prepared. Electrode patterns were printed on photo paper by micro‐pen writing printing. The prepared paper electrode can detect nitrate using electrochemical analysis. The results show that the paper electrodes prepared with the three conductive inks can be used for the analysis of potassium ferricyanide and potassium nitrate. The minimum square resistance of paper electrodes prepared with silver conductive ink is 0.11 Ω/sq. It can be cycled 60 times in electrochemical applications with small standard deviation and high reproducibility and stability. Analysis and detection can also be performed in nitrate concentrations ranging from 60 μM to 1000 μM. This low silver‐containing, green, and low resistivity flexible electrode offers a solution for the simplicity and economy of electronic devices.