Cant seem to hurt the 2D enemy

I have tried various ways to inflict damage and nothing seems to work… this is my latest attempt:

using UnityEngine;
using System.Collections;
using System;

public class FireBlast : MonoBehaviour
{
public float speed;
private Player player;
private int BaseLayer;

public int damagePerShot = 20;
public float timeBetweenBullets = 0.15f;
public float range = 50f;

float timer;
Ray2D FirePoint;
RaycastHit2D shootHit;
int shootableMask;
float effectsDisplayTime = 0.2f;

void Start()
{
    player = FindObjectOfType<Player>();

    if (player.transform.localScale.x < 0){
        speed = -speed;
        transform.localScale = new Vector3(-1f, 1f, 1f);
    }
}

void FixedUpdate()
{
    GetComponent<Rigidbody2D>().velocity = new Vector2(speed, GetComponent<Rigidbody2D>().velocity.y);
}

void OnTriggerEnter2D(Collider2D other)
{
    // Reset the timer.
    timer = 0f;

    // Set the shootRay so that it starts at the end of the gun and points forward from the barrel.
    FirePoint.origin = transform.position;
    FirePoint.direction = transform.forward;

    // Perform the raycast against gameobjects on the shootable layer and if it hits something...
    if (Physics2D.Raycast(FirePoint.origin, shootHit.point, range, shootableMask, 10f))
    {
        // Try and find an EnemyHealth script on the gameobject hit.
        EnemyHealth enemyHealth = shootHit.rigidbody.GetComponent<EnemyHealth>();

        // If the EnemyHealth component exist...
        if (enemyHealth != null)
        {
            // ... the enemy should take damage.
            enemyHealth.TakeDamage(damagePerShot, shootHit.point);
        }
    }
}

}

I am trying to kill enemies with a basic health system… Please help!

So that is triggers on contact of the enemy collider.