intersection test between two objects in unity

this C# script is to detect collision between two objects. let's say there is a player and a enemy, add player & enemy with collider, add the script to the enemy, and then do something..in this case, enemy will be destoyed.

using UnityEngine;
using System.Collections;
public class col : MonoBehaviour {
 public float collisionRadius = 1.1f;
 private GameObject _player;

 void Start() {
     _player = GameObject.FindGameObjectWithTag("Player");
 }

 void Update() {
     Vector3 playerPoint = _player.collider.ClosestPointOnBounds(transform.position);
     float playerRadius = Vector3.Distance(_player.transform.position, playerPoint);

     if (Vector3.Distance(transform.position, _player.transform.position) <= collisionRadius + playerRadius) {
         // Do something!
Debug.Log ("Hello");
         GameObject.Destroy(gameObject);
     }
 }
}