Laser-scribed graphene presents an opportunity to print a new generation of disposable electrochemical sensors

Abstract

Graphene application within electrochemical sensing has been widely reported, but mainly as a composite, which adds summative effects to an underlying electrode. In this work we report the use of laser-scribed graphene as a distinct electrode patterned on a non-conducting flexible substrate. The laser-scribed graphene electrode compared favourably to established carbon macroelectrodes when evaluating both inner sphere and outer sphere redox probes, providing promise of extensive utility as an electrochemical sensor. The laser-scribed graphene electrode demonstrated the fastest heterogeneous electron transfer rate of all the electrodes evaluated with a k(0) of 0.02373 cm s(-1) for potassium ferricyanide, which exceeds commercially available edge plane pyrolytic graphite at 0.00260 cm s(-1), basal plane pyrolytic graphite at 0.00033 cm s(-1) and the very slow and effectively irreversible electrochemistry observed using single layer graphene. Finally and most significantly, a proof of principle system was fabricated using the laser-scribed graphene as working electrode, counter electrode and underlying base for the Ag/AgCl reference electrode, all in situ on the same planar flexible substrate, removing the requirement of macroscale external electrodes. The planar three electrode format operated with the same optimal electrode characteristics. Furthermore, the fabrication is inexpensive, scalable and compatible with a disposable biosensor format, considerably widening the potential applications in electrochemical bio-sensing for laser-scribed graphene.

Breathable Nanowood Biofilms as Guiding Layer for Green On‐Skin Electronics

“…However, the compressive resistance of our porous biofilms is still insufficient for keeping a stable CN alignment structure for a “reliable” heat‐ and sweat‐guidance when on‐skin use. Our recent work demonstrated that 1) constructing a laser‐reduced graphene oxide (L‐rGO) film covering the AD‐BCA film even increased the E r and H to 23.761 and 12.493 GPa, respectively ( E r = 0.89 TPa and H = 0.95 TPa for monolayer graphene, E r and H decrease as the graphene layer number increases, and E r approaches the constant of bulk graphite (≈27 GPa) as layer number > 6), and 2) L‐rGO film is breathable and protects the pore structure of AD‐BCA substrate film from compacting by laser shock . Furthermore, rGO film also serves as the electrical functional layers in sensors, nanogenerators, etc., of On‐skinE.…”

Nanomaterial‐enabled Rapid Detection of Water Contaminants

“…For the future development of water sensors, several directions are proposed. First, printing technology has been widely used for sensor electrode fabrication . Similar to the blood glucose sensor using a testing strip to collect the blood sample, electrodes could also be fabricated on a disposable testing strip and used for water contaminant detection.…”

Laser‐Scribed Graphene Oxide Electrodes for Soft Electroactive Devices

“…[14] Such laser-scribed graphene oxide (LSGO) can be produced under a range of different conditions e.g., using femtosecond lasers, [15] pulsed CO2 lasers, [16] or continuous diode lasers [17] and has even been demonstrated using a commercial LightScribe® DVD drive. [18] Laser scribing is an easy method to produce high-detail, conductive patterns on GO films and LSGO has already been used to fabricate a range of different devices such as supercapacitors, [18] various sensors, [19][20][21][22] electronic components such as transistors [23] or memory [24] and even loudspeakers [25] and LEDS. [26] Electrodes for ionic polymer actuators have also been fabricated.…”