Reduction and widespread consumption of fossil fuels have been diverted researcher attention towards alternative energy resources and a variety of biomass resources (energy crops, agricultural waste, animal waste and municipal waste) conversion into bioethanol production. Here, we have evaluated the efectiveness of green synthesized zinc oxide in term of harvesting efciency, reducing sugar and fermentation products. Biomass was harvested by ZnO nanoparticles and got 92.9% harvesting efciency within 5 min at 200 mg/L of ZnO nanoparticles. ZnO-harvested algae treated with nitric acid, sodium hydroxide, and potassium hydroxide give highest reducing sugars ranging from 150 to 200 μg/μL. The average value of bioethanol percentage varies between 1.60 and 6.02% among all samples which were fermented using Saccromyces cerivicae (yeast) as fermenting agent. Highest ethanol was shown by ZnO-harvested algae treated with nitric acid, sodium hydroxide, and potassium hydroxide which was in range of 3.78–6.02% v/v. Green synthesized nanoparticles method with reducing agent coating is an interesting and fascinating multiple application as compared to conventional physical and chemical methods. The outcome of this work is very useful for local biomass conversation into frst and second-generation bioethanol production on large scale commercial process
