MySQL utf-8

<?php
//>=php 5.3.6
try {
    $user = '';
    $pass ='';
    $db = 'my_nick';
    $dbh = new PDO("mysql:host=localhost;dbname=$db;charset=utf8", $user, $pass);
    $dbh->exec("CREATE TABLE IF NOT EXISTS `$db`.`tabella2` (
    `campo` varchar(6) NOT NULL
    ) ENGINE=MyISAM DEFAULT CHARSET=utf8");
    $stmt = $dbh->prepare("INSERT INTO `$db`.`tabella2` (`campo`) VALUES (:value)");
    $stmt->bindParam(':value', $value, PDO::PARAM_STR, 6);
    $value = "\xC3\xA0".'bc';
    $stmt->execute();
    foreach($dbh->query("SELECT `campo` from `$db`.`tabella2`",PDO::FETCH_ASSOC) as $row) {
        header('Content-type: text/plain; charset=utf-8');
        print_r($row);
    }
    $dbh = null;
} catch (PDOException $e) {
    print "Error!: " . $e->getMessage() . "\n";
    die();
}
?>