Process-property correlations in laser-induced graphene electrodes for electrochemical sensing

Abstract

Laser-induced graphene (LIG) has emerged as a promising electrode material for electrochemical point-of-care diagnostics. LIG offers a large specific surface area and excellent electron transfer at low-cost in a binder-free and rapid fabrication process that lends itself well to mass production outside of the cleanroom. Various LIG micromorphologies can be generated when altering the energy input parameters, and it was investigated here which impact this has on their electroanalytical characteristics and performance. Energy input is well controlled by the laser power, scribing speed, and laser pulse density. Once the threshold of required energy input is reached a broad spectrum of conditions leads to LIG with micromorphologies ranging from delicate irregular brush structures obtained at fast, high energy input, to smoother and more wall like albeit still porous materials. Only a fraction of these LIG structures provided high conductance which is required for appropriate electroanalytical performance. Here, it was found that low, frequent energy input provided the best electroanalytical material, i.e., low levels of power and speed in combination with high spatial pulse density. For example, the sensitivity for the reduction of K3[Fe(CN)6] was increased almost 2-fold by changing fabrication parameters from 60% power and 100% speed to 1% power and 10% speed. These general findings can be translated to any LIG fabrication process independent of devices used. The simple fabrication process of LIG electrodes, their good electroanalytical performance as demonstrated here with a variety of (bio)analytically relevant molecules including ascorbic acid, dopamine, uric acid, p-nitrophenol, and paracetamol, and possible application to biological samples make them ideal and inexpensive transducers for electrochemical (bio)sensors, with the potential to replace the screen-printed systems currently dominating in on-site sensors used. Graphical abstract

Laser-Induced Graphene Based Flexible Electronic Devices

“…Meanwhile, the conductivity, electrochemical performance [24,27,35,36], biocompatibility [37,38], and hydrophobicity [39][40][41] of LIG also have been systematically studied. A variety of LIG devices have been developed, including sensors [14][15][16][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42], supercapacitors [17,[43][44][45][46][47][48][49][50][51][52][53][54][55], nanogenerators [54][55][56][57][58]…”

“…Furthermore, a variety of natural and synthetic materials, ranging from plants [ 22 , 23 , 24 ], textiles [ 24 , 25 , 26 , 27 ], papers [ 28 , 29 , 30 ] to other organic films [ 17 , 27 , 31 , 32 , 33 , 34 ], are experimentally demonstrated in serving as the carbon source to form LIG. Meanwhile, the conductivity, electrochemical performance [ 24 , 27 , 35 , 36 ], biocompatibility [ 37 , 38 ], and hydrophobicity [ 39 , 40 , 41 ] of LIG also have been systematically studied. A variety of LIG devices have been developed, including sensors [ 14 , 15 , 16 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 ], supercapacitors [ 17 , 43 , 44 , …”

“…Meanwhile, the conductivity, electrochemical performance [ 24 , 27 , 35 , 36 ], biocompatibility [ 37 , 38 ], and hydrophobicity [ 39 , 40 , 41 ] of LIG also have been systematically studied. A variety of LIG devices have been developed, including sensors [ 14 , 15 , 16 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 ], supercapacitors [ 17 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 ], nanogenerators [ 54 , 55 , 56 , 57 , 58 , 59 , 60 , …”

'All In One' SARS-CoV-2 variant recognition platform: Machine learning-enabled point of care diagnostics

“…Graphene is a well-known promising material for various chemical or biosensing applications due to its highly advanced electrical and mechanical properties( Behrent et al, 2021 ; Kaidarova et al, 2020 ; Novoselov et al, 2012 ). Additional to various chemical synthesis methods, it was discovered that direct lasing of polymers forms high quality graphene by photothermal reactions( Beduk et al, 2020 ).…”

Compared EC-AFM Analysis of Laser-Induced Graphene and Graphite Electrodes in Sulfuric Acid Electrolyte

“…In this novel one-step process, the porous graphene film was patterned by pointing a CO 2 laser onto a commercial polyimide foil in an ambient environment. No baking step nor need of materials, other than polyimide foil, were required [ 41 , 42 ]. Among the different carbon-containing materials, the first material used as a precursor was Kapton, a classic polyimide developed in the 1960s by DuPont.…”