Laravel bulk insert optimization

I'm currently using a make shift INSERT on DUPLICATE UPDATE function that relies on a DB raw query from eloquent. I'm looking to improve the quality of the code and the speed. Please take a look

function bulkInsertBookTable($data)
{
    $inserts = [];
    foreach ($data as $item) {
        $inserts[] = implode(', ', ['"' . $item['book_id'] . '"', $item['isbn']]);
    }

    $inserts = Collection::make($inserts);

    $inserts->chunk(500)->each(function($ch) {
        $insertString = '';
        foreach ($ch as $element) {
            $insertString .= '(' . $element . '), ';
        }

        $insertString = rtrim($insertString, ", ");

        try {
            DB::insert("INSERT INTO book_datas (`book_id`, `isbn`) VALUES $insertString ON DUPLICATE KEY UPDATE `isbn`=VALUES(`isbn`)");
        } catch (\Exception $e) {
            print_r([$e->getMessage()]);
        }
    });
}

NOTE:

createOrUpdate function is only valid on model level and does not allow mass insert. Doing Model::insert() will allow to have a $data = [] inserted as long as fillable is used however it will reject if there is a duplicate key