A pupil from Wellington College in Belfast has won the overall Northern Ireland award at the BT Young Scientist and Technology exhibition.
Harvey Donnelly won the best project prize for his work on electrochemical cell reactions.
St Killian’s College in Ballymena was named best Northern Ireland school.
Four thousand two hundred and fifty-one pupils entered 2,031 science projects for the awards, held at the RDS in Dublin.
The winners at the 54th annual awards were announced on Friday night.
A pupil from Colaiste Choilm in Cork, 15-year-old Simon Meehan, took the overall top award and a prize of 7,500 euros.
He discovered a natural antibiotic in the blackberry plant which could be effective in combating bacteria, including that which causes the hospital-acquired infection MRSA.
The prestigious education exhibition and awards have been held since 1963 and attract thousands of visitors.
A number of pupils from St Killian’s College also won individual awards in the technology categories.
Ellen Martin and Rachel McAuley received first place in the junior technology awards while Niall Black, Orla McNaughton and Ciaran Cairns received third place in the senior award.
Pupils from Loreto College in Coleraine, Cookstown High School, St Mary’s College in Londonderry and South-Eastern Regional College also received awards.
The Department of Education permanent secretary Derek Baker was at the RDS to congratulate the Northern Ireland prizewinners.