PDO

<?php
    require_once 'conf.php';

    class Conecta extends conf{

        var $pdo;

        function __construct(){
            $pdo = new PDO('mysql:host='.$this->host.':dbname='.$this->db, $this->usuario, $this->senha);
        }

        function login($email, $senha){
            $stmt = $this->PDO->prepare("SELECT * FROM usuarios WHERE email = :email AND senha = :senha");
            $stmt->bindValue(":email",$email);
            $stmt->bindValue(":senha", $senha);

            $exec = $stmt->execute();
            $run = $stmt->fetchAll(PDO::FETCH_ASSOC);
            return self::$run;
        }
    }