After json_encode() 100⬠became 100âÂ\u0082¬

Question

I am making an api in which i fetch data which contains column some special character value when i convert them in json format it's value is change from 100⬠to 100âÂ\u0082¬ . I don't want this \u0082 extra characters .

Here is my code

$UserDetailSql    = "SELECT * FROM `characteristic` WHERE event_id='" . $events->id . "'"; 
 //$this->_db->my_query("SET NAMES 'UTF8'");
 $UserDetailSqlVal = $this->_db->my_query($UserDetailSql);
 $temp_char = array();
 while($characteristic = $this->_db->my_fetch_object($UserDetailSqlVal)){
     $char_temp['characteristic_id'] = $characteristic->characteristic_id; 
     $char_temp['title_description'] = $characteristic->title;
     $char = $this->_common->getEventCharacterstics($characteristic->characteristic_id);
     $char_temp['title'] = $char->title; 
     $char_temp['image'] = IMG_PATH.'characterstics/'.$char->image; 
     $temp_char[] = $char_temp;
}
$temp['characteristic'] = $temp_char;
echo json_encode($temp);`   

Here $characteristic->title can have catalan or spanish or english data.The value i give in heading is this column.

I tried utf8_encode(),htmlentities(),htmlspecialcharacters() but no luck please help i am fed up now.Thanks in advance.