A Graphene-Based Glycan Biosensor for Electrochemical Label-Free Detection of a Tumor-Associated Antibody.
Filip KvetonAnna BlsakovaLenka LorencovaMonika JerigovaDusan VelicOla BlixtBo JanssonPeter KasakJan TkacPublished in: Sensors (Basel, Switzerland) (2019)
The study describes development of a glycan biosensor for detection of a tumor-associated antibody. The glycan biosensor is built on an electrochemically activated/oxidized graphene screen-printed electrode (GSPE). Oxygen functionalities were subsequently applied for covalent immobilization of human serum albumin (HSA) as a natural nanoscaffold for covalent immobilization of Thomsen-nouvelle (Tn) antigen (GalNAc-O-Ser/Thr) to be fully available for affinity interaction with its analyte-a tumor-associated antibody. The step by step building process of glycan biosensor development was comprehensively characterized using a battery of techniques (scanning electron microscopy, atomic force microscopy, contact angle measurements, secondary ion mass spectrometry, surface plasmon resonance, Raman and energy-dispersive X-ray spectroscopy). Results suggest that electrochemical oxidation of graphene SPE preferentially oxidizes only the surface of graphene flakes within the graphene SPE. Optimization studies revealed the following optimal parameters: activation potential of +1.5 V vs. Ag/AgCl/3 M KCl, activation time of 60 s and concentration of HSA of 0.1 g L-1. Finally, the glycan biosensor was built up able to selectively and sensitively detect its analyte down to low aM concentration. The binding preference of the glycan biosensor was in an agreement with independent surface plasmon resonance analysis.
Keyphrases
- label free
- electron microscopy
- high resolution
- cell surface
- carbon nanotubes
- room temperature
- mass spectrometry
- atomic force microscopy
- ms ms
- human serum albumin
- solid phase extraction
- single molecule
- ionic liquid
- magnetic resonance
- liquid chromatography
- quantum dots
- high throughput
- risk assessment
- magnetic resonance imaging
- single cell
- solid state
- high performance liquid chromatography
- transcription factor
- climate change
- hydrogen peroxide
- dna binding
- low density lipoprotein