The current study explored an aqueous banana fruit (Musa Acuminata) peel extract to synthesise zinc oxide nanoparticles (ZnO NPs) via a green approach. Powder X-ray diffraction (PXRD) revealed that the produced NPs exhibited an average crystal size of about 35 nm. The XRD pattern confirmed the formation of crystalline ZnO NPs with hexagonal wurtzite structure with space group P6_3mc. The SEM pictures unequivocally showed agglomerated and uneven morphologies for ZnO NPs. The UV-Visible and UV-DRS studies showed the maximum absorbance of 302 nm and the energy gap value of 3.46 eV. The synthesized ZnO NPs exhibit greater photodegradation efficiency when exposed to Fast Orange(FO) dye under UV light in a span of 120 min. The maximum zone of inhibition of 16 mm was recorded for the calcined ZnO NPs against the Gram-negative bacteria Escherichia Coli. The electrochemical impedance spectroscopy (EIS) revealed an enhanced behaviour of ZnO NPs' which can be attributed to their reduced charge transfer resistance. Lithium was detected by the modified ZnO electrode sensor at extremely low concentrations of 1–5 mM. These findings confirmed the multifunctional applications of the synthesized biogenic ZnO NPs.