Graphene nanoribbon derived from multi-walled carbon nanotube: An efficient viral gene hosting and biosensing molecular platform for the electroanalysis of HIV-1 gene

Abstract

Graphene nanoribbon (GNR) is a carbon nanomaterial with strikingly distinct characteristics compared to graphene. GNRs possess high aspect ratio, variable band gap, high surface area and high density of reactive edge states which make it an emerging flat molecular platform alternative to graphene. GNR is not much explored in sensing applications compared to graphene. Here, for the first time, we are reporting the application of GNRs, derived from multiwalled carbon nanotube (MWCNT), as an efficient flat molecular platform for hosting and biosensing of Human immune deficiency virus-1 (HIV-1) gene. For the construction of HIV-1 sensor, GNRs were synthesized by unzipping of MWCNTs and deposited onto glassy carbon electrode (GCE) followed by the immobilization of HIV-1 probe (ssDNA) onto the resulting GCE/GNR platform to obtain GCE/GNR/ssDNA sensor. Subsequently, the sensor was employed in the analysis of target gene (cDNA) by measuring the voltammetric response generated from hybridization between ssDNA and cDNA. Differential pulse voltammetry (DPV) responses recorded at different target gene concentrations displayed perfect linear correlation (R2 = 0.991). The sensor exhibited low detection limit (2.3 aM), low quantification limit (7.67 aM) and high sensitivity (5.5 μA aM−1 cm−2) which is possibly due to synergic effects of GNRs. Sensor exhibited acceptable stability, repeatability and displayed good selectivity when tested with mismatched target DNA sequences. Further, sensor’s diagnostic applicability was verified by spiking target gene in human blood sample which showed high recovery (4 %) indicating its practical utility in the electroanalysis of HIV-1 gene in human blood samples.