A solid state electrochemiluminescence (ECL) sensor based on Ru(bpy)32+-encapsulated silica nanoparticles (RuNP) covalently immobilised on a screen printed carbon electrode has been developed and characterised. RuNPs were synthesised using water-in-oil microemulsion method. amino groups were introduced on their surface. and they were characterised by transmission electron microscopy. https://foldlyers.shop/product-category/screws/