Explosion dont work

I have a fireball prefab, which i attatch a particle system. Then with this code i want to launch when collides ) ontriggerenter) :

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 
 //Fireball script that reacts to collisions of other enemies, at the start with PlayerCharacterElyEnemy, could add others...
 
 
 public class FireballMainCharacter : MonoBehaviour {
 
     // Use this for initialization
     public float speed=10.0f;
     public int damage=1;
     private ParticleSystem exp;
     //public ParticleSystem exp;
 
     void Start () {
         // Move the object forward along its z axis speed*unit/second.
     //this.gameObject.transform.Translate(0, 0, speed * Time.deltaTime);
     exp = GetComponent<ParticleSystem>();
     }
 
     // Update is called once per frame
     void Update () {
         // Move the object forward along its z axis speed*unit/second.
     //this.gameObject.transform.Translate(0, 0, speed * Time.deltaTime);
     this.gameObject.transform.Translate(0, 0, speed * Time.deltaTime);
     }
 
     //Called when another object collides with this trigger
     void OnTriggerEnter( Collider other){
 
         
         PlayerCharacterElyEnemy player= other.GetComponent<PlayerCharacterElyEnemy>();
         
         //Check if other object is PlayerCharacter
         if( player!= null) {
                 Debug.Log("ElyEnmy: llamo a hurt" + player.name);
                 player.Hurt(damage);
                 //player.transform.Rotate(-75, 0, 0);
             }
     //    Debug.Log("Other hit" + other.name);
 //        player.transform.Rotate(-75, 0, 0);
         Explode();
         //IMPORTANT: We have to destroy the fireball, once it has been collided with other object....before check with objects
         Destroy(this.gameObject);
 
     } // End OnTriggerEnd
 
     public void Explode() {
       //  var exp = GetComponent<ParticleSystem>();
         exp.Play();
         Debug.Log("Explode done");
         Destroy(gameObject, exp.duration);
     }
 }

But actually it doesnt work... any ideas ?? Also any tips or recommended settings to have a nice explosion ? This is for a gun shoot, i need also another to laser shoot, and cannon shoot....

Thanks