Yes, there might be. Fanfiction websites like FanFiction.net or Archive of Our Own could potentially have such stories. However, it's not a very common or mainstream plot within the Naruto fanfiction realm. You'd have to search through these platforms using relevant keywords to find one.
In this fanfiction, Percy might sacrifice himself in a grand battle. He could be facing a powerful enemy that was about to strike Zoe. Percy, being the heroic type, jumps in front of Zoe at the last moment. His last thoughts could be of his friends and all the adventures he had. Zoe, in turn, is left with a deep sense of guilt and sorrow, vowing to carry on Percy's legacy. She might become even more determined to fight for the cause they both believed in, all while mourning the loss of her dear friend.
In this kind of fanfiction, it's often a very tragic and heroic concept. Percy sacrificing himself to save the seven would be a huge shock to the other characters. It might lead to a lot of grief and also a new sense of purpose for the remaining seven. They would have to carry on with their mission while also dealing with the loss of Percy, which could add a lot of depth to their character development.
Well, in a 'sakura dies saving team 7 fanfic', the plot could go like this. Sakura might be in a situation where Team 7 is facing an overwhelming threat. She could put herself in harm's way to buy time for Naruto, Sasuke and Kakashi. For example, if they are being attacked by a group of powerful ninjas, Sakura might use her chakra - enhanced strength to create an opening for the others to flee. And in the end, she succumbs to her injuries while the rest of Team 7 is saved.
The theme of legacy is also quite common. Percy's death leaves behind a legacy that the other characters have to uphold. They have to carry on his mission of protecting Olympus and also keep his memory alive. There's also often a theme of grief and how the characters deal with the loss of someone so important.
I haven't come across a particular 'naruto dies saving sasuke fanfic' myself. However, you might want to check Naruto - centered forums where fans discuss and share such stories. Maybe by asking around in those communities, you'll find what you're looking for.
One possible plot could be that Sarada gets into a dangerous situation, like being attacked by a powerful enemy. Sakura, being her mother, jumps in to protect her without hesitation. Sakura uses all her medical ninjutsu skills and combat abilities to fend off the enemy, but in the end, she sacrifices herself to ensure Sarada's safety.
I'm not sure of a specific 'naruto dies saving kakashi fanfiction' off - hand. You could try searching on fanfiction - dedicated websites like Archive of Our Own or FanFiction.net.
Perhaps there's a prophecy involved. The fanfic could be set up where it's foretold that Boruto will bring about a great change, but only if he survives a certain threat. Naruto, aware of this, sacrifices himself to ensure Boruto lives on. This could then trigger a series of events where Boruto has to deal with the political fallout in the village, as some may blame him for Naruto's death, while others see him as the key to the future. It could also lead to a rift between Boruto and some of his friends who struggle to understand why Naruto had to die for him.
Perhaps the village is invaded by a horde of powerful demons. Naruto, after a long and grueling battle, realizes that the only way to stop them is to seal them all away, like the way the Fourth Hokage sealed the Nine - Tails. But this sealing jutsu demands the life of the caster. Without hesitation, Naruto performs the jutsu, sacrificing himself to save the village he loves so much.