eg

grab.cs

using UnityEngine;
using System.Collections;

public class grab : MonoBehaviour {

	// Use this for initialization
	void Start () {
	
	}
	
	// Update is called once per frame
	void Update () {
	
        RaycastHit2D hit = Physics2D.Raycast(transform.position, Vector2.right);
        Debug.DrawRay(transform.position, Vector2.right);
        if (hit.collider != null) {
        	Debug.Log("grabbed " + hit.collider.name);
        } else {
        	Debug.Log("nothing");
        }
	}
}