Electrochemical HO sensor based on a Au nanoflower-graphene composite for anticancer drug evaluation.

Reliable HO sensors for in situ cellular monitoring under drug stimulation can be developed as a powerful and versatile tool for drug evaluation. Herein, a novel electrochemical biosensor capable of detecting and quantifying HO was fabricated by graphene and shape-controlled gold nanostructures. With the help of polyelectrolytes, gold exhibited hierarchical flower-like nanostructures. This kind of nanozyme material exhibited a prominent electrochemical response for HO. Electrocatalytic activity for HO reduction with high sensitivity (5.07◊10 mA μmol L cm) and good detection capability (the lowest detection limit is 4.5 μmol L (S/N = 3)) were achieved. This electrochemical biosensor was successfully used to measure the concentration of HO released from HepG2 hepatoma cells. Ascorbic acid (AA) and Camellia nitidissima Chi saponins (CNCS) were selected as model drugs, and their anticancer activities were compared by in situ monitoring of HO. Interestingly, the electrochemical sensor showed remarkable sensitivity, accuracy, and rapidity compared with the traditional enzymatic detection kit. In brief, the as-synthesized nanostructured HO sensors can be applied to assess the antitumor properties of candidate drugs and inspire developments for personalized health care monitoring and cancer treatment.