A novel amperometric biosensor for hydrogen peroxide and glucose based on cuprous sulfide nanoplates

A facile, greener and template free route has been developed to produce cuprous sulfide (Cu₂S) nanoplates (NPs) with average diameters of 70-150 nm, via one step solvothermal decomposition of a single-source precursor (SSP) Cu(ACDC)₂ [ACDC = 2-aminocyclopentene-1-dithiocarboxylate] in the presence of ethylenediamine (EN) and triethylenetetramine (TETA) as structure orienting agents. The precursor complex and nanomaterials were thoroughly characterized by several common techniques and measurements, which give the composition and characteristics of the materials. Amperometric biosensors for hydrogen peroxide (H₂O₂) and glucose have been constructed by immobilizing the synthesized Cu₂S NPs in glutaraldehyde on a glassy carbon (GC) electrode using a direct drop-coating method. The proposed sensor has displayed faster response, high and reproducible sensitivity (64.27 μA mM⁻¹) with linear range of 10 μM to 3.75 mM, towards the electrochemical biosensing of H₂O₂ at -0.35 V (vs. Ag/AgCl). The sensor also showed high and reproducible sensitivity (61.67 μA mM⁻¹) towards glucose determination with linear range of 10 μM to 3.1 mM. The anti-inference ability of electroactive molecules and favorable stability are some of the advantages of the proposed sensor. Finally, using the sensor we have determined the glucose concentration in a human blood serum sample. The results strongly demonstrate the usefulness of Cu₂S NPs for biosensor design and other biological applications.