DestruirAlContacto.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class DestruirAlContacto : MonoBehaviour {

    public GameObject explosion;

    void OnTriggerEnter2D(Collider2D colision) {
        if (colision.tag == "Frontera") {
            return;
        }

        Instantiate (explosion, transform.position, transform.rotation);
        Destroy(colision.gameObject);
        Destroy(gameObject);
    }
}