Ultralight 3D Graphene Oxide Aerogel Decorated with Pd-Fe Nanoparticles for the Simultaneous Detection of Eight Biomolecules

In this proof-of-concept study, anultralight grapheneoxide aerogel(GOx-Aero) decorated with bimetallic palladium-iron nanoparticles(Pd-Fe) was synthesized and immobilized on a glassy carbonelectrode (GCE) for electrochemical sensor applications. The mainobjective of this work was to develop a sensitive electrochemicalsensor capable of simultaneously detecting eight biomolecules, includingascorbic acid (AA), dopamine (DA), uric acid (UA), 8-hydroxyguanine(8HG), guanine (G), adenine (A), thymine (T), and cytosine (C). Tothe best of our knowledge, this is the first time that an electrochemicalsensor has been able to detect eight biomolecules simultaneously.The bimetallic GOx aerogel significantly enhanced the performanceof the sensor by increasing the electroactive area, conductivity,and anodic peak current response. The sensor demonstrated sharp, well-defined,and continuous oxidation peaks for all eight analytes of interestand wide linear ranges of 5.0-1750, 0.25-100.0, 0.5-500.0,0.5-375.0, 0.5-500.0, 0.5-500.0, 5.0-1500.0,and 5.0-1500.0 mu M for AA, DA, UA, 8HG, G, A, T, and C,respectively. The prepared sensor also exhibited excellent stability,reproducibility, and sensitivity with a very low limit of detection(LOD) of 553.7, 1.8, 69.6, 43.2, 42.9, 72.3, 57.2, and 318.4 nM forAA, DA, UA, 8HG, G, A, T, and C, respectively. The Pd-Fe-GOx-Aero-GCEwas also tested in various real samples such as artificial saliva,artificial cerebrospinal fluid (CSF), salmon sperm DNA, and genomicDNA from calf thymus, where it demonstrated good recovery values.Additionally, the novel developed sensor was used to monitor the interactionbetween the anticancer drug, cisplatin, which has well-described bindingaffinity with the G and A bases in DNA. Overall, Pd-Fe-GOx-Aero-GCEdisplayed an extremely promising platform not only for the simultaneousdetection of eight biomolecules in complex biological matrices butalso for DNA-drug interaction studies toward the developmentof electrochemical high-throughput drug screening assays, which isof great importance in the field.