Electrochemical biosensors are promising platforms for the detection of biomarkers. In particular, plasmonic-assisted electrochemical sensors offer high sensitivity and low LOD, yet the electrical properties need to be improved. Here, we propose a non-enzymatic, sunlight-driven nanostructured plasmonic assisted electrochemical electrode for the ultrasensitive and quantitative detection of hydrogen peroxide (H2O2). Briefly, the electrode is fabricated through a simple fab-less technique which produces a non-compact self-assembly monolayer of beads on a Si wafer, followed by a metal deposition, wet-chemical etching for nanocavity formation and then finalized with exfoliated Graphene (Gr) drop-cast. The nanocavities formation was studied through morphological, optical, and electrochemical characterization via FESEM, UV-Vis, and cyclic voltammetry, electrochemical impedance spectroscopy, and chronoamperometry (CA), respectively. Nanocavities optimization demonstrated the benefits of combining gold electrochemical catalytic properties with nanocavities plasmonic effect. Moreover, the addition of Gr grants a reduction in the electrode’s resistivity of more than 70 %, suggesting electron mobility enhancement of the electron transfer. Herein, the electrical properties of the proposed electrode offer a highly sensitive sensor with a high affinity towards the detection of low concentrations of H2O2 via CA, with an outstanding low LOD of 1 pM in a linear range of 1 pM-100 mM. Additionally, the proposed device successfully detected and measured the increased levels of H2O2 released from human cancer cells over healthy cell lines in PBS buffer and diluted human plasma. Furthermore, we successfully implemented the proposed electrode and integrated it with a controlled fluidic sample deliver in a portable fashion.

Development of a simple and fab-less electrode for the plasmon-enhanced electrochemical detection of hydrogen peroxide released from human cancer cells

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.