Abstract
Features of layer-by-layer (LbL) self-assembled graphene based flexible cancer sensor Detection limit of prostate specific antigen (PSA) is down to 4 fg/ml (0.11 fM). Label free and HRP labeled. Low cost due to self assembly technique and polyethylene terephthalate (PET) substrate.
(a) Schematic illustration of interaction between capture antibodies and target protein molecules in a label free detection. After graphene biosensor modified by capture antibodies encounters PSA solution, the immunoreaction will take place, and the conductance of graphene changes due to the absorption of PSA on the surface of the graphene. (b) Schematic illustration of a graphene sensor in a labeled detection. HRP labels the different concentration of PSA, and catalyzes the conversion from ascorbic acid to dehydroascorbic acid, causing the local pH shifts. The conductance of graphene is sensitive to pH shifts. 

Detection limit of prostate specific antigen (PSA) is down to 4 fg/ml (0.11 fM). Label free and HRP labeled. Low cost due to self assembly technique and polyethylene terephthalate (PET) substrate.
(a) Schematic illustration of interaction between capture antibodies and target protein molecules in a label free detection. After graphene biosensor modified by capture antibodies encounters PSA solution, the immunoreaction will take place, and the conductance of graphene changes due to the absorption of PSA on the surface of the graphene. (b) Schematic illustration of a graphene sensor in a labeled detection. HRP labels the different concentration of PSA, and catalyzes the conversion from ascorbic acid to dehydroascorbic acid, causing the local pH shifts. The conductance of graphene is sensitive to pH shifts. 

{'paper_id': '120118041', 'title': 'An ultrasensitive and low-cost graphene sensor based on layer-by-layer nano self-assembly', 's2_url': 'https://api.semanticscholar.org/CorpusID:120118041', 'source': 'S2ORC'}