Highly selective trace level detection of DNA damage biomarker using iron-based MAX compound modified screen-printed carbon electrode using differential pulse voltammetry

Abstract

In this work, we demonstrate a facile, one-step synthesis of iron-based MAX compound (Fe3AlC2 nanoflakes) modified screen-printed carbon electrode (FAC/SPCE) for non-enzymatic, trace-level electrochemical detection of DNA damage biomarker 8‑hydroxy-2′-deoxyguanosine (8OHdG) in human biofluids. The SEM micrographs and XRD reveals the flake-like morphology and crystallographic phase of the Fe3AlC2 nanoflakes. The FAC/SPCE sensor exhibits a wide linear detection range from 100 pM to 100 μM of 8OHdG with high sensitivity (i.e., 23.85 μA/nM.cm2) and a very low detection limit (LOD) of 50 pM. This outstanding performance of the FAC/SPCE sensor can be ascribed to the good electrical conductivity and electrocatalytic activity of the Fe3AlC2 nanoflakes facilitated with Al2+/Al3+ redox couple. In addition, the sensor displays an outstanding selectivity towards 8OHdG in the presence of serums albumins obtained from human (HSA) and bovine (BSA) and other interfering metabolites like glucose (Glu), dopamine (DA), ascorbic acid (AA) and uric acid (UA). The sensor is efficacious towards trace-level recognition of 8OHdG in simulated human blood serum with good recovery percentages ranging from ∼96.96% to ∼101.48%. This excellent performance of the sensor over other reported electrochemical sensors proves it as an ideal bioanalytical platform for the medical diagnosis of various deadly diseases and disorders.