Screen-Printed Carbon Nanotube Electrodes (CNT-SPEs) as Flexible Electrochemical Biosensors, CFEBSPCNTE

Screen-Printed Carbon Nanotube Electrodes (SPCNTE) incorporate single-walled (SWCNTs) or multi-walled carbon nanotubes (MWCNTs) into thick-film planar strips. By introducing a 3D percolating network of high-aspect-ratio carbon, they address the principal limitation of standard screen-printed carbon electrodes (SPCEs): sluggish electron transfer kinetics caused by insulating polymer binder coverage.

The Primary Sensor Implementations: (1) Dehydrogenase-Based Enzymatic Biosensors: Oxidizing enzymatically generated NADH at low voltages (+0.2 V) enables amperometric detection of ethanol (alcohol dehydrogenase), lactate (lactate dehydrogenase), and malate without electrode fouling. (2) Neurotransmitter Resolving Platforms: The negative surface charge of carboxylated CNTs separates the overlapping oxidation potentials of Ascorbic Acid (AA), Dopamine (DA), and Uric Acid (UA) into discrete, well-resolved differential pulse voltammetric (DPV) peaks separated by >150 mV}. (3) High-Capacity Immunosensing Matrices: Acid-treated MWCNTs display dense surface carboxyl groups (-COOH). Standard carbodiimide chemistry (EDC/NHS) covalently anchors capture antibodies or DNA aptamers with significantly higher surface density than planar graphite. (4) Trace Stripping Analysis of Heavy Metals: Combined with bismuth (Bi) or gold (Au) nanoparticles, the 3D CNT scaffold enhances stripping peak resolution and limits of detection for trace Pb^{2+}, Cd^{2+}, and As^{3+}.

References:

1. H. Beitollahi, et al., Applications of electrochemical sensors and biosensors based on modified screen-printed electrodes: a review, Anal. Methods (2020) 12 (12): 1547–1560.
2. Keiichiro Yamanaka, et al. Printable Electrochemical Biosensors: A Focus on Screen-Printed Electrodes and Their Application, Analytical and Bioanalytical Chemistry, 2005, 382, 884–886.