Highly Efficient Carboxylated Graphene Oxide-Based Surface Plasmon Resonance Aptasensors Detect hCG Protein to Diagnose Down's Syndrome in Clinical Serum Samples
27 Pages Posted: 28 Jan 2019
Date Written: January 25, 2019
This study developed a surface plasmon resonance (SPR) aptasensor suitable for the detection of clinical serum biomarkers. Studies in precision medicine clearly emphasize the need for a carboxyl-functionalized graphene oxide (GO) biosensing material that can rapidly and accurately detect a low concentration of biomolecules to identify various diseases. The developed carboxyl-GO-based SPR aptasensor showed excellent sensitivity and limit of detection without the use of antibodies and without any specific preference. An hCG protein detection limit of 1 pg/mL in buffer samples and 1.9 pM in clinical serum samples were achieved. The results showed that the carboxyl-GO-based chip was well below the normal physiological level of serum protein (0.5 ng/mL). A high correlation coefficient was obtained in the range of 1.9 pM to 135 pM. The results showed a serum hCG concentration of 30.18 to 135 pM with a 5k-fold dilution factor, and that an SPR angle shift of more than 30 millidegrees (m°) was associated with a significant risk of fetal Down's syndrome (DS) compared to normal pregnant women. The results clearly showed that the detection of hCG protein in serum samples from pregnant women at 12-19 weeks can diagnosis Down's syndrome with high selectivity and sensitivity. Our findings suggest the potential application of carboxyl-GO film in proof-of-concept studies for serum assays as a new type of SPR material, and that peptide and carboxyl-GO films may be conducive to the development of future point of care testing and rapid diagnostic devices for a clinical cancer diagnosis and prognosis.
Keywords: surface plasmon resonance (SPR), Aptasensor, Carboxyl-functionalized graphene oxide (GO-COOH), Peptides, human chorionic gonadotropin (hCG), Down's syndrome (DS)
Suggested Citation: Suggested Citation