3D Carbon Microelectrodes with Bio-Functionalized Graphene for Electrochemical Biosensing

Abstract

An enzyme-based electrochemical biosensor has been developed with 3D pyrolytic carbon microelectrodes that have been coated with bio-functionalized reduced graphene oxide (RGO). The 3D carbon working electrode was microfabricated using the pyrolysis of photoresist precursor structures, which were subsequently functionalized with graphene oxide and enzymes. Glucose detection was used to compare the sensor performance achieved with the 3D carbon microelectrodes (3DCMEs) to the 2D electrode configuration. The 3DCMEs provided an approximately two-fold higher sensitivity of 23.56 µA·mM−1·cm−2 compared to 10.19 µA mM−1·cm−2 for 2D carbon in glucose detection using cyclic voltammetry (CV). In amperometric measurements, the sensitivity was more than 4 times higher with 0.39 µA·mM−1·cm−2 for 3D electrodes and 0.09 µA·mM−1·cm−2 for the 2D configuration. The stability analysis of the enzymes on the 3D carbon showed reproducible results over 7 days. The selectivity of the electrode was evaluated with solutions of glucose, uric acid, cholesterol and ascorbic acid, which showed a significantly higher response for glucose.

A review on graphene based transition metal oxide composites and its application towards supercapacitor electrodes

“…Despite of the invincibleness graphene is an good conductor of heat, electricity and optically transparent [6,7]. Because of the amazing characteristics graphene has been selected for a broad range of applications ranging from electronics to optics bio-devices and sensors [8][9][10]. Recently Nano-technologists are quite enthusiastic about graphene.…”

Functionalized Carbon Materials for Electronic Devices: A Review

“…These types of biosensors can be used as an efficient indicator of sugar level for biological diagnoses. Hemanth et al [97] also reported an enzyme-focused electro-chemical biosensor. This biosensor was fabricated using a 3D pyrolytic carbon micro-electrode that was deposited with biologically functionalized rGO.…”

“…Hemanth et al [97] fabricated a bio-functionalized graphene 3D carbon electrode biosensor. The reduction and functionalization of Hummers-modified GO was obtained by treatment with branched polyethylenimine (PEI) in a single reaction [98].…”

“…( a ) Schematic illustration of 2D and 3D carbon-based biosensors, reproduced with permission from [97], published by MPDI, 2018; ( b ) graphene-based sensor chip above holder reproduced with permission from [100], published by Elsevier, 2016; and ( c ) synthetic layout of rGO-TiO 2 thin-film sensor, reproduced with permission from [105], published by Elsevier, 2017.…”

Pathogen detection with electrochemical biosensors: Advantages, challenges and future perspectives

“…Especially, 3D-structured nanomaterials, e.g., graphene, have been used in electrochemical nano-biosensors, which could further enhance the sensitivity compared 2D-structures [ 19 ]. In another study, pyocyanin toxin from cystic fibrosis patients was detected with an amperometric electrochemical nano-biosensor.…”