how would i give an effect to a person if they have a custom item in there offhand

give @a emerald[custom_name='["",{"text":"Wealth Shard","italic":false,"bold":true,"color":"dark_green"}]',lore=['["",{"text":"Have you ever wanted to ","italic":false,"color":"green"}]','["",{"text":"be rich all the power ","italic":false,"color":"green"}]','["",{"text":"with money take this shard","italic":false,"color":"green"}]','["",{"text":"and show how strong Plutus is","italic":false,"color":"green"}]']] (Ps that the item and im really new to this)