Whisk the egg, buttermilk, hot sauce and 3/4 teaspoon of seasoned salt together in a bowl until smooth. Place the chicken breasts into a resealable zip top bag, and pour the buttermilk mixture over top. Press out the air and seal. Marinate in the refrigerator 3 hours to overnight.
Preheat deep fryer to 350 degrees F.
Combine the flour and bread crumbs with 1/4 teaspoon of seasoned salt, and pepper in a pie dish or shallow pan. Drain the chicken breasts from the marinade, and shake off the excess. Press into the bread crumb mixture, and gently shake off the excess.
Fry the chicken in the hot oil until brown and crispy on the outside and no longer pink on the inside, about 10 minutes. Drain on a paper towel-lined plate before serving.