Electrochemical Biosensor of Nanocube-Augmented Carbon Nanotube Networks

Abstract

Networks of single-walled carbon nanotubes (SWCNTs) decorated with Au-coated Pd (Au/Pd) nanocubes are employed as electrochemical biosensors that exhibit excellent sensitivity (2.6 mA mM(-1) cm(-2)) and a low estimated detection limit (2.3 nM) at a signal-to-noise ratio of 3 (S/N = 3) in the amperometric sensing of hydrogen peroxide. Biofunctionalization of the Au/Pd nanocube-SWCNT biosensor is demonstrated with the selective immobilization of fluorescently labeled streptavidin on the nanocube surfaces via thiol linking. Similarly, glucose oxidase (GOx) is linked to the surface of the nanocubes for amperometric glucose sensing. The exhibited glucose detection limit of 1.3 muM (S/N = 3) and linear range spanning from 10 muM to 50 mM substantially surpass similar CNT-based biosensors. These results, combined with the structure's compatibility with a wide range of biofunctionalization procedures, would make the nanocube-SWCNT biosensor exceptionally useful for glucose detection in diabetic patients and well suited for a wide range of amperometric detection schemes for clinically important biomarkers.

The Electrochemical Behavior of Au/AuNPs/PNA/ZnSe-QD/ACA Electrode Towards CySH Oxidation

“…Detection of biomolecules at low concentrations is critically important to the early diagnosis and successful treatment of diseases [1][2][3]. In addition, there have been continuous researches for fabrication of new electrode materials for developing new sensitive and selective electrochemical biosensors for the detection of the trace amounts of biomolecules [1][2][3].…”

“…In addition, there have been continuous researches for fabrication of new electrode materials for developing new sensitive and selective electrochemical biosensors for the detection of the trace amounts of biomolecules [1][2][3]. Sulfur-containing amino acids, such as homocysteine (HCySH) and L-cysteine (CySH) play crucial roles in biological systems for the diagnosis of disease states [4,5].…”

Enhanced Control of Single-Walled Carbon Nanotube Properties Using MPCVD with DC Electrical Bias

“…Chiral selectivity, with respect to metallic or semiconducting behaviour, is important for optimal operation of many types of devices. Metallic CNTs are obviously well suited for applications requiring high current carrying capacity, such as electrical interconnects (Close, et al, 2008;Kreupl, et al, 2002); however, they may also be advantageous in devices requiring high sensitivity to small electrical potential changes, such as electro-chemical biological sensors (Claussen, et al, 2009). Field effect transistors utilizing semiconducting SWNT channels have been extensively studied and have been found to exhibit ballistic electronic transport even at room temperature operation (Franklin and Chen, 2010).…”

Enzyme-based Electrochemical Biosensors

“…Many efforts have been made to detect the biomolecules at very low concentrations. Networks of SWCNTs decorated with Au-coated Pd nanocubes are employed as electrochemical biosensors showing a limit of detection as low as 2.3 nM for H 2 O 2 , in which Au-coated Pd nanocubes were grown at the defect sites of template SWCNT networks through a simple electrodeposition process (Claussen et al, 2009). Fig.…”