Model and conroller relationship laravel 5

I'm new at laravel, and i have some problem to manage relationship with model and controller.

I have indexcontroller, where called:

$usersModel = new \App\Models\Users();
if ($usersModel->checkOnExistsByEmail($params['user_email'])){
     //...find it
}

Model file:

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class Users extends Model {
    protected $table = 'users_data';

    public function scopeCheckOnExistsByEmail($query,$email){

        $count = $query->where('user_email','=',$email)->count();
        if ($count == 0){
            return false;
        }else{
            return true;
        }

    }

}

After that i've got an a error:

Object of class Illuminate\Database\Eloquent\Builder could not be converted to string

Could someone explain whats i do wrong? Thank you very much.

via Chebli Mohamed