1. Trace Analysis and Biosensor Research Center; Prince of Songkla University, Hat Yai; Songkhla 90112 Thailand, Tel: +66-74-288753 Fax: +66-0-7455-8849
2. Center of Excellence for Innovation in Chemistry, Faculty of Science; Prince of Songkla University, Hat Yai; Songkhla 90112 Thailand
3. Department of Chemistry, Faculty of Science; Prince of Songkla University, Hat Yai; Songkhla 90112 Thailand
4. Department of Applied Science, Faculty of Science; Prince of Songkla University, Hat Yai; Songkhla 90112 Thailand
5. Department of Physics, Faculty of Science; Prince of Songkla University, Hat Yai; Songkhla 90112 Thailand