Highly Loaded Mildly Edge‐Oxidized Graphene Nanosheet Dispersions for Large‐Scale Inkjet Printing of Electrochemical Sensors

Abstract

Inkjet printing of electrochemical sensors using a highly loaded mildly edge-oxidized graphene nanosheet (EOGN) ink is presented. An ink with 30 mg/mL EOGNs is formulated in a mixture of N-methyl pyrrolidone and propylene glycol with only 30 min of sonication. The absence of additives, such as polymeric stabilizers or surfactants, circumvents reduced electrochemical activity of coated particles and avoids harsh postprinting conditions for additive removal. A single light pulse from a xenon flash lamp dries the printed EGON film within a fraction of a second and creates a compact electrode surface.An accurate coverage with only 30.4 μg of EOGNs per printed layer and cm 2 is achieved. The EOGN films adhere well to flexible polyimide substrates in aqueous solution. Electrochemical measurements were performed using cyclic voltammetry and differential pulse voltammetry. An all inkjet-printed threeelectrode living bacterial cell detector is prepared with EOGN working and counter electrodes and silver-based quasi-reference electrode. The presence of E. coli in liquid samples is recorded with four electroactive metabolic activity indicators.

Evaluation of Inkjet-Printed Reduced and Functionalized Water-Dispersible Graphene Oxide and Graphene on Polymer Substrate—Application to Printed Temperature Sensors

“…Applications of such materials include flexible conductive tracks [ 29 ], chemical sensors and TFTs [ 30 ], photodetectors [ 32 ], and RF circuits [ 33 ]. More specifically, inkjet-printed graphene dispersions in cyclohexanone–terpineol as solvents and ethyl cellulose as stabilizer [ 35 ] have been used for the development of FETs [ 36 ], micro-supercapacitors-energy storage devices [ 37 , 38 , 39 , 40 , 41 ], optical devices and photodetectors [ 42 ], sensors [ 43 ], and antennas [ 44 ].…”

Voltammetry in Two‐Electrode Mode for Rapid Electrochemical Screening Using a Fully Printed and Flexible Multiplexer Sensor

“…Figure 2 presents the cyclic voltammograms of these 4 mediators in 0.1 M KNO 3 for comparison of their working potential ranges. [Fe(CN) 6 ] 3−/4− was scanned from −0.4 to 0.4 V, FcMeOH from −0.3 to 0.3 V, Ru[(NH 3 ) 6 ]Cl 3 from −0.7 to 0 V and K 2 [IrCl 6 ] from 0.2 to 1 V [28,29] …”

Additive Manufacturable Materials for Electrochemical Biosensor Electrodes

“…[ 270,271 ] The effect of IJP layers on electrochemical performance was recently investigated using graphene ink. [ 272 ] An electrochemical signal was detected using two deposited layers, however, subsequent increases in layers was discovered to increase both the peak and capacitive currents. This inferred that the real surface area and overall porosity increased as more layers were deposited.…”