A sliver deposition signal-enhanced optical biomolecular detection device based on reduced graphene oxide

Abstract

The development of high-sensitive biomolecular detection system is of great significance for diseases early diagnosis. The novel optical sensor based on the polarization-sensitive absorption of graphene has a great potential in biological detection. However, the detection sensitivity of the device can hardly meet the needs of clinical analysis currently. This study applies sliver deposition signal amplification to the optical biomolecular detection device based on reduced graphene oxide for the sensitive immunoassay. In redox cycling enzymatic silver deposition reaction, the more alkaline phosphatase label bound on chip surface will cause a faster silver deposition rate. The specific antibody detection confirms that the sliver deposition can enhance the detection signal significantly. In cardiac biomarker Creatine Kinase-MB measurement, the minimum detection concentration is 0.1 ng/mL. To be more important, within the range from detection limit to 10 ng/mL, the signal intensity is highly correlated with target protein concentration, so the biomolecular detection device can meet clinical assay requirements. The signal-enhanced optical biomolecular detection device based on reduced graphene oxide shows excellent sensitivity and selectivity, and provides a new strategy for biomolecules detection, which can be applied in diseases accurate prediction and diagnosis.