Reduced graphene oxide-gadolinium oxide-functionalized paper based immunosensor for electrochemical detection of gentamicin

Excessive consumption of antibiotics like gentamicin (GEN) can lead to hostile effects as antibiotic resistance. Therefore, the detection is important for which, reduced graphene oxide-Gadolinium oxide nanocomposite (rGO@Gd2O3 NC) was composed through co-precipitation method by using of rGO for the detection of GEN. The structural, morphological and functional group characterization were done using XRD, FT-IR, SEM and TEM techniques. The cyclic voltammetry (CV) shows excellent electrocatalytic activity and superior performance towards GEN detection. Through the use of GEN monoclonal antibodies (anti-GEN) on a screen-printed electrode (SPE), a very sensitive electrochemical immunosensor was fabricated. Covalent interactions were employed to construct the electrochemical immunosensor, while bovine serum albumin (BSA) was employed as a blocking agent on the anti-GEN/rGO@Gd2O3/SPE electrode surface. The analysis of the CV response of the BSA/anti-GEN/rGO@Gd2O3/SPE bioelectrode demonstrated linear detection range from 1 pM – 100 μM, along with limit of detection (LOD) of 0.424 pM and sensitivity of 44.87 μA pM-1 cm− 2. Additionally, rGO@Gd2O3 immunosensor, exhibited a good level of linearity with R2 value of 0.981. These findings indicate the excellent potential of the rGO@Gd2O3 electrochemical immunosensor for accurately detecting GEN in milk samples containing spiked concentrations.