▎ 摘　　要

The development of low-cost, disposable electrode materials has been at the forefront of sensor technology in recent decades. Paper, offers possibilities for multi-functional, disposable and economically friendly sensing capabilities and has proved to be a suitable reagent storage and substrate material in paper-based analytical devices (PADs). In this work, we report a simple inkjet printing procedure on photographic paper for the fabrication of single analyte electrochemical sensors. A three-electrode system, consisting of a 3 mm diameter working electrode (WE), a counter electrode (CE) and a reference electrode (RE) were prepared by inkjet printing of silver conductive inks for comparison to common commercial screen printed electrode (SPE) brands. In a second step, carbon coating and modification of the working electrode surface with an electrochemically reduced graphene oxide, gold nanoparticle (ERGO-AuNP) film, to improve electrode sensitivity and selectivity was employed. Improved electron-transfer kinetics, increased active surface area and enhanced catalytic properties were achieved due to the ERGO-AuNP layer inclusion. Electrical and topographical characterization of the printed layers was performed in the fabrication process. Printing of Ag-NP ink showed good resistivity (1.8-6.3 omega) on photographic paper. The prepared printed paper-based electrodes (PPE) offer a quantitative analysis of Ni(II), based on the accumulation of Ni(dmgH)(2) complexes at the modified electrode surface by square-wave adsorptive cathodic stripping voltammetry (SW-AdCSV). This study offers the first investigation on the feasibility of adsorptive electrochemical sensing methods at porous cellulose paper-based substrates. Instrumental parameters including deposition potential and deposition time were optimized for both electrochemical sensors. Improved sensitivities were achieved at the modified integrated electrodes over the unmodified derivate with a limit of detection (LOD) of 32.19 mu g L-1 achieved for the ERGO-AuNP-CC-Ag-PPE. This is well below the EPA and WHO standards of 0.1 mg L-1 or 0.1 ppm for Ni2+ in drinking water.