Opto-electrochemical functionality of Ru(II)-reinforced graphene oxide nanosheets for immunosensing of dengue virus non-structural 1 protein

Peptide-based direct electrochemical detection of receptor binding domains of SARS-CoV-2 spike protein in pristine samples

“…Raman spectroscopy is a nondestructive chemical analysis technique that is used to investigate the lattice network and electronic properties of GO and MB-GO sheets [35] , [38] , [40] Using a 532 nm laser, the Raman spectra of MB, GO, and MB-GO ( Fig. S5 ( b )) samples were recorded.…”

“…C-N symmetrical stretching (1388 cm -1 ) and C-C ring stretching were visible in the spectra of pure MB (1627 cm -1 ) [41] Furthermore, the GO spectra exhibits four distinct peaks at 1583, 2703, 1350, and 1623 cm -1 , which are attributed to the G, G', D, and D' bands, respectively. The G and G' bands are formed by the C-C bond stretch and are shared by all sp 2 carbon atoms in a 2D hexagonal lattice [35] , [42] The double resonance process activates first and second order Raman scattering, resulting in the formation of these bands. Furthermore, the occurrence of D and D' bands is linked to lattice deformation or defects involving sp 3 carbon atoms [42] The in-plane optical branches (longitudinal and transverse modes) are responsible for both D bands.…”

“…The surplus electrode materials on the surface were gently removed by immersing for 2 seconds in a PBS solution [28] , [29] , [30] , [31] , [32] To avoid non-specific bindings, the electrode was treated with bovine serum albumin (BSA) solution (4 μL, 0.05 mg/mL). After rinsing with PBS buffer for 2 s, the prepared BSA/NP/ b /MB-GO/SPE sensor platform was demonstrated for probing SARS-CoV-2 SP antigen [33] , [34] , [35] …”

Human virus detection with graphene-based materials

“…Bio-affinity layers of protein-G at the GO-Ru(II) electrode interface supported the localization of monoclonal antibodies selective for binding the epitopes of non-structural 1 protein antigen. Chronoamperometric or fluorescence quenching based immunoassays allowed detection of DENV with LOD of 0.5 ng mL −1 ( Kanagavalli and Veerapandian, 2020 ). Jin et al prepared an impedimetric biosensor based on 3-aminopropyltriethoxysilane (APTES) functionalized GO for DENV detection via primer hybridization using different oligonucleotide sequences.…”

Graphene-based analytical lab-on-chip devices for detection of viruses: A review

“…Jin et al 49 designed a surface-based impedimetric biosensor using self-assembled functionalized GO wrapped SiO2 particles for label-free detection of dengue virus with LOD 1fM. Opto-electrochemically active ruthenium bipyridine complex was attached to the surface of GO by Kanagavalli et al 50 for the detection of the dengue virus. The immunosensor showed a linear response both under the chronoamperometric and fluorescence quenching-based immunoassays with a LOD of 0.38 and 0.48 ng/mL, respectively.…”