Cascading reaction of arginase and urease on a graphene-based FET for ultrasensitive, real-time detection of arginine

Abstract

Herein, a biosensor based on a reduced graphene oxide field effect transistor (rGO-FET) functionalized with the cascading enzymes arginase and urease was developed for the detection of L-arginine. Arginase and urease were immobilized on the rGO-FET sensing surface via electrostatic layer-by-layer assembly using polyethylenimine (PEI) as cationic building block. The signal transduction mechanism is based on the ability of the cascading enzymes to selectively perform chemical transformations and prompt local pH changes, that are sensitively detected by the rGO-FET. In the presence of L-arginine, the transistors modified with (PEI/urease(arginase)) multilayers showed a shift in the Dirac point due to the change in the local pH close to the graphene surface, produced by the catalyzed urea hydrolysis. The transistors were able to monitor L-arginine in the 10-1000 μM linear range with a LOD of 10 μM, displaying a fast response and a good long-term stability. The sensor showed stereospecificity and high selectivity in the presence of non-target amino acids. Taking into account the label-free, real-time measurement capabilities and the easily quantifiable, electronic output signal, this biosensor offers advantages over state-of-the-art L-arginine detection methods.

Arginase as a Potential Biomarker of Disease Progression: A Molecular Imaging Perspective

“…The classical labeling of L-arginine with stable carbon and nitrogen isotopes ( 13 C and 15 N) allows studying the metabolic flux of this amino acid in normal or pathological tissue samples by magnetic resonance and mass spectroscopy [ 92 ]. Currently, the development of novel, highly sensitive, reliable, and reproducible methods to evaluate arginase in real time remains an active research topic [ 213 , 214 , 215 ]. These in vitro analytical methods may be useful for screening potential arginase inhibitors and assessing the extent of their inhibitory activity.…”

Novel Graphene Biosensor Based on the Functionalization of Multifunctional Nano-bovine Serum Albumin for the Highly Sensitive Detection of Cancer Biomarkers

“…According to the calculated value (122.8 ng mL −1 ) of K d , the available receptors on the dBSA functionalized GFETs biointerface were sufficient for the detection of CEA molecules under different concentrations in this study. According to the fitting results, the limit of detection was estimated to be approximately 337.58 fg mL −1 , which was lower than for other graphene FET biosensors [41,61,62]. Well-defined drain-source current changes were observed for low CEA concentrations (337.58 fg mL −1 ) in diluted serum, which were much smaller than the cutoff value (5 ng mL −1 ) used in clinical diagnosis.…”

Recent Progress in the Development of Biosensors for Chemicals and Pesticides Detection

“…The functionality of the FETs biosensors have been enhanced through applied nanomaterials such as graphene, carbon nanotubes, and metals oxides [102], [107], [108]. The use of graphene and graphene-related nanomaterials in FETs have presented switchable charge-carrier mobility through their interaction with molecules [106].…”

“…The use of graphene and graphene-related nanomaterials in FETs have presented switchable charge-carrier mobility through their interaction with molecules [106]. Biosensors based on nanomaterials field-effect transistors have gained much attention as a cutting-edge approach in the biosensor application due to their attractive features such as their excellent performance in aqueous solution, real-time and fast response, high sensitivity and operated at very low voltage [107], [109], [110].…”