Mohadeseh Zarei Ghobadi - Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran
Sayed-Hamidreza Mozhgani - Department of Virology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
Hedayatollah Ghourchian - Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran

Designing efficient biosensors for early detection of viruses are important. Although, the usual techniques comprising real-time polymerase chain reaction (RT-PCR) and Enzyme-linked immunosorbent assay (ELISA) are highly selective, they are time-consuming, expensive, and need to professional operators. Nanomaterial-based biosensors can be utilized to develop biosensors. Graphene oxide (GO) denotes a two-dimensional honeycomb lattice composed of single-layer carbon atoms, which can absorb the biomolecules on its surface. Moreover, gold nanoparticles (AuNPs) with inimitable optical properties can quench the fluorescence of the carbon nanomaterials like graphene oxide and carbon nanotube. Herein, we developed a new biosensor for long segment detection of the human T cell-lymphotropic virus 1 genome via designing proper probes and tracing the fluorescence energy transfer between graphene oxide and gold nanoparticle. The fluorescence emission of GO was quenched when probes-AuNPs were adsorbed on its surface. In order to enhance the quenching efficiency, both two probes were functionalized with AuNPs, thus high number of AuNPs were placed close to the GO sheets. In the presence of target, the probes were desorbed from the GO surface and hybridized with the target. As a result, the fluorescence emission of GO nanosheets was recovered . The limit of detection of the biosensor was determined to be around 10 pg/mL. Our results proposed that the further development may be useful to detect other viruses.

Biosensor, Graphene oxide, Gold nanoparticles, HTLV-1